ACCORDING to the international panel on climate change (IPCC) any direct temperature rise from increasing carbon dioxide levels is greatly amplified by positive feedback from water vapour. As the theory goes, rising carbon dioxide levels from human activity causes some temperature rise which causes more water to evaporate. Because water vapour is the dominant greenhouse gas, the additional water vapour absorbs even more energy, so global temperatures rise even, more causing still more water to evaporate and so on in an amplifying spiral. In this way the roughly half degree direct impact from doubling carbon dioxide is claimed to be amplified to three degrees or more.
An interesting theory, but now consider the following scenario;
We know the earth rotates about an axis tilted about 23 degrees relative to the sun. This is what causes the seasons and what sets the Tropics of Cancer and Capricorn. Imagine a location on the Tropic of Capricorn (23 degrees south) – say Mackay in Queensland. In summer the sun is directly overhead – average solar input of around 310 watts/sq meter. In winter the sun is at maximum elevation 44 degrees – average solar input of around 220 watts/sq meter. That is a difference summer to winter of about 90 watts/sq meter which, according to Stefan’s law, without any feedbacks would give a temperature difference summer to winter of about 16 degrees. The amount of positive or amplifying feedback claimed by the IPCC would inflate that about 6 times to more than 90 degrees C, extinguishing all life in Mackay.
Yet according to the long term records from the Bureau of Meteorology, the average summer maximum is 30.3C and the winter maximum 22C, a difference of less than 8 C. That is not only far less than 90 degrees but is far less than even the 16 degrees predicted in the absence of any feedback at all. How is that possible?
Maybe the thermal mass of the environment averages out much of the summer winter difference? Unlikely, consider the significant temperature change between day and night. If the temperature can change significantly in a few hours it could certainly change profoundly over 6 months. Also, if the above were the reason one would also expect to see it similarly averaged out in other places. Yet if we compare Mackay with say Alice Springs, both are at very similar latitudes yet again according to the Bureau of Meteorology long term records the summer maximum in Alice Springs is 36.4 and the winter maximum 19.7C a difference very close to the predicted 16C and double that of Mackay. Interestingly, not only is the summer winter difference greater at Alice Springs but the annual average is also greater 28C versus 26C and this is despite the fact that Alice Springs is at an elevation of 550metres which should make it 3.5 degrees cooler.
What does stand out at Mackay relative to Alice Springs is that the humidity is much higher in summer than it is in winter. Higher humidity means more water vapour content in the air and a higher summer temperature increases the water vapour content even further. But isn’t this going the wrong way? According to the IPCC, all this extra water vapour should massively increase the retained heat, making the temperature difference between summer and winter much larger not smaller. It should also raise the average temperature compared to Alice Springs not reduce it.
Well maybe the green house effect acts very slowly taking a long time to become apparent. Certainly IPCC has suggested exactly that with claimed time constants in decades. Our senses can give us some insight into that claim. Step outside any winters evening and you can immediately tell if the sky is cloudy or clear. I am sure most of you will agree from personal experience that it will be much colder when the sky is clear and a thermometer will confirm it. This comes about because clouds act exactly like greenhouse gasses, trapping energy radiated from the surface. Indeed clouds form a significant part of the overall greenhouse effect. Of course, clouds, unlike green house gases, also have a second effect and that is to reflect incoming solar energy away from Earth (the albedo effect). Again anyone who has been outside when a cloud comes between them and the sun can testify that the drop in radiant energy is immediately detectable. What our simple experiments are showing is that green house effects are clearly detectable at a very local level over time scales much less than a day, rather than only over 10’s of years.
So how is it possible that the summer/winter temperature variation at Mackay is so much less than the change in solar input would suggest? The reason is that water vapour generates lots of feedback effects and many of them are very strongly negative (feedback that reduces the impact of changes in energy input). Evaporating water takes a very large amount of energy. As more water evaporates in the summer it absorbs the necessary energy from the environment reducing the temperature rise. Greater humidity also leads to more condensation and thus clouds which reflect a larger fraction of the incoming solar energy back out to space and away from Earth’s surface. It also takes energy to lift the water vapour several kilometres into the atmosphere against earth’s gravity to the altitude where it condenses to form clouds and falls back as rain (after all that is where the energy for hydroelectricity comes from). The temperature data clearly shows that these negative feedback mechanisms strongly dominate over the slight increase in retained energy with increasing water vapour concentration.
The IPCC temperature rise claims are based on an assumption of strong net positive feedback in our climate system yet natural systems virtually all exhibit strong negative feedback around an equilibrium point. Negative feedback is the opposite of positive feedback. It acts to oppose any disturbance acting on a system and seeks to maintain the current equilibrium. In short it is a stabilising factor whereas positive feedback is a destabilising factor. Long term stability of any natural system almost guarantees that there is strong negative or stabilising feedback in operation. The climate, while showing periodic variations, has been stable enough for life to form and flourish for millions of years despite significant changes in forcing over the millennia and this makes it virtually certain that strong negative feedback is in operation. The fact that IPCC claim a large degree of positive feedback in our climate system suggests there may be a flaw in their theory.
If, as I believe, the net feedback from water vapour is negative rather than positive then the actual temperature rise by 2070 even with a doubling of carbon dioxide is likely to be less than the half a degree predicted in the absence of feedback, probably no more than 0.2 to 0.3 degrees.
by Michael Hammer
Melbourne, Australia
*********************************
Michael Hammer graduated with a Bachelor of Engineering Science and Master of Engineering Science from Melbourne University. Since 1976 he has been working in the field of spectroscopy with the last 25 years devoted to full time research for a large multinational spectroscopy company.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
I’ll go further than MH and say water is a temperature moderator, mitigating the trend in either direction; which is also a step up from Miskolczi who allocates a role for water in OD maintainence; or is that the same as Miskolczi?
Anyway, the AGW idea that water should produce an enhanced greenhouse effect is counterintuitive and frankly imbecilic.
Don’t you just hate it when engineers, those of us trained to make scientific theories actually work, stick their noses into academic sacred cows?
This thread is going to be interesting because as it is a thoughtful comment not relying on peer reviewed sources, the AGW crowd here will have to start relying on their own understanding of physics, or lack of, to counter it.
What a well thought out piece, with illustrations we lurkers can relate to. Back in the days when Dr Pielke Sn r. had comments on his website I asked whether the IPCC models had fully compensated for the many ways that water cools in its cycle, and from memory, he said he didn’t believe they had, and that it warranted further investigation. I manage to make use of these properties of water by cooling my house evaporatively, situated by choice in a dry warm area in summer, with only
150watts of power.
A piece that seems to put most of the arguments about the makeup of greenhouse gases, as apart from their sheer pressure, to one side is here, thanks to a pointer from Jae on WUWT
http://www.ilovemycarbondioxide.com/pdf/Rethinking_the_greenhouse_effect.pdf
I have heard the argument before, but this does use NASA’s own figures.
Julian; you may be interested in this piece, about atmospheric pressure, which Alan Siddons also recommended;
http://www.geocities.com/atmosco2/atmos.htm?200820
“Anyway, the AGW idea that water should produce an enhanced greenhouse effect is counterintuitive and frankly imbecilic.”
So you accept that there is a greenhouse gas effect and G&T are wrong?
What a terribly ill thought out piece. Where does the figure of 6 come from, as a multiplier? Does the author understand anything about the characteristic response times of the climate system? Temperatures drop at night, yes, in response to a forcing of -1360 W/m². But how far towards the equilibrium response do they get? How long would they take to reach the equilibrium response? I don’t think the author has even thought that these questions were relevant, let alone considered the answers.
Michael, of course water vapor cools. It isn’t a feedback, its a direct term. It’s right there in the Kiehl and Trenberth diagram – a latent heat flux of 78 W/m2. That’s the global average, over arctic, deserts and all, night and day. So if 78 is the average, then of course under the summer tropic sun the latent heat flux is huge, and removes an enormous amount of heat. It would be comparable to sunlight.
But the heat doesn’t vanish; it is all given back when the vapor condenses. That is why it is treated as a vertical transport term. But it is removed for long enough that it smoothes out the daily max, as people here remark.
What your logic is missing is the effect of horizontal transport of both sensible and latent heat. This is also very great, but doesn’t change the heat budget of the Earth. It does however even out the effects of local water vapor blocking of IR. As you allow, this is actually fairly slow.
That’s the reason why water vapor has a big feedback effect to amplify global warming (from any cause). It makes a small change to IR transmission, but that change operates everywhere, night and day, and the temperature builds up over years. The heat that it blocks stays in the system. But locally, the excess heat of IR blocking due to local humidity moves horizontally hundreds of kilometers a day and is quickly mixed.
RW, I assume the figure 6 is from the realistic .5 DegC rise in the coming century compared to the 3 DegC figured by the IPCC due to “forcings”
Thank you cohenite, that paper was very interesting and should be more widely publicised, it puts a lot of very elegant nit picking in its place, the waste paper basket!
Nick; your assertion that horizontal transport of water vapor evens out the effect of local water vapor blocking out IR overlooks the other side of the equation; increased albedo; SH is increasing slightly at near surface levels where clouds and increased albedo come into play; upper atmosphere water is declining increasing the window; this, of course, was the subject of MH’s first paper.
Nick Stokes
“The heat that it blocks stays in the system. ”
Based on observation or theory?
Well done MH! In my experience he is always right.
“Anyway, the AGW idea that water should produce an enhanced greenhouse effect is counterintuitive and frankly imbecilic.”
So you accept that there is a greenhouse gas effect and G&T are wrong?
“Well done MH! In my experience he is always right.”
Except that Nick Stokes just pointed out why he is wrong.
Louis
Based on incontrovertible theory. Latent heat does not leave the Earth. Wind does not leave the Earth. The only heat energy that leaves the Earth is IR radiation. And that only leaves in response to elevated temperatures.
Coho, your missing the point. Albedo is a different feedback, but also does not produce significant local response. Horizontal transport by wind and moving water vapor is much faster, but does not move heat from the Earth. IR transport is smaller, but does affect the Earth’s energy budget. The heat goes more slowly (in W/m2), but then it’s gone.
“Albedo is a different feedback, but also does not produce significant local response.” We’ll let that go for a moment; your comment about radiation being the only heat removalist from the Earth overlooks this;
http://www.agu.org/pubs/crossref/2003/2003GL018363.shtml
Cohenite, I’ll take your silence as agreement that there is a greenhouse effect, and G&T are wrong.
Nick “Latent heat does not leave the Earth.”
However as the water condenses to form clouds it radiates to space almost without obstruction whereas the downward radiation is impeded.
“And that only leaves in response to elevated temperatures.”
Given the equation for radiation heat loss is
Q = \epsilon \sigma [Th^4 – Tc^4]
( http://www.engineeringtoolbox.com/radiation-heat-transfer-d_431.html )
Where Th ~ 288K and Tc ~ 3K the temperatures are always elevated and will be for billions of years to come yet.
Commenter jae wrote on this more than a year ago. Idso published on climate sensitivity calculations back in the late 1990’s, over various time scales. I replicated their interseasonal analysis using solar insolation and weather data (winter-summer differences) from several dozen locations scattered around the US. The data is all readily available from US government websites. The climate sensitivity averaged out to 0.1 C/W/m^2, or about 0.4 C for a doubling of CO2 (3.7 W/m^2 added forcing). Inland (lower humidity) was about 0.15 C/W/m^2, and coastal (higher humidity) was about 0.05 C/W/m^2.
Increased water vapor is overall a negative feedback effect in the real world.
A neat post. Sure you have not included advection, but it is the principle that counts. Do the GCMs include the seasonal and diurnal effects? This fits in nicely with your previous posting. How anyone can believe in positive feedback effects defeats me. There is no historical evidence for positive feedbacks and resulting “tipping points”. All previous climate shifts have been due to solar effects (Milankovitch etc), plate tectonics, volcanoes, etc.
Quite right. No evidence for sudden, rapid climate change at all. No wild jumps in temperature at all over the last 450,000 years! Clearly, the very gradual changes in solar insolation due to orbital variations correspond exactly with those very gradual changes you can see in the graph.
Comment from: Louis Hissink April 1st, 2009 at 9:04 pm
“Nick Stokes
“The heat that it blocks stays in the system. ”
Based on observation or theory?”
I am surprised at the question.
The heat staying “in the system” is simply a matter of definition. If heat is blocked from escaping into outer space, (by the “greenhouse effect”) it remains in the earth atmosphere system.
If you are going to start a discussion that the GHE is not a factor, doesn’t exist, or is contrary to the first and second law of thermodynamics as some deniers have argued, that is another matter.
If you don’t believe the greenhouse effect exists, that is another discussion entirely.
RW: All due to CO2 then?
I think that author of the blogpost is overestimating his competence and underestimating the competence of the scientists who research climate for a living. This seems to be a problem with a lot of so called climate sceptics.
For some reason, Dr Hammer neglected to analyse the effect of the latent heat of vaporization. He was so pleased to find a supposed hole in the AGW theory, that he overestimated how thorough and correct his analysis is. He left out a component in the heat budget of a region that is essential to understanding of climate.
I find this is a frequent occurence among those who post their work in the blogosphere.
Scientists who do research regularly and publish peer reviewed work, are less likely to make such an error, because they are taught to have humility.
Nick Stokes wrote: “Michael, of course water vapor cools. It isn’t a feedback, its a direct term. It’s right there in the Kiehl and Trenberth diagram – a latent heat flux of 78 W/m2. That’s the global average, over arctic, deserts and all, night and day. So if 78 is the average, then of course under the summer tropic sun the latent heat flux is huge, and removes an enormous amount of heat. It would be comparable to sunlight.
But the heat doesn’t vanish; it is all given back when the vapor condenses. That is why it is treated as a vertical transport term. But it is removed for long enough that it smoothes out the daily max, as people here remark.”
Isn’t it more accurate to say here, rather than giving back heat when water vapor condenses, increased water vapor decreases the lapse rate, causing radiation to be emitted at a higher altitude(than would OTW be the case)? When water vapor at the top of a column of air condenses, it will transfer that energy to the air below it, *not to the surface*. It seems pretty clear that the farther away from the surface that radiation is when it is ultimately emitted, the less likely it will be to find its way back to the surface.
Cheers, 🙂
Michael:
Great post (because it agrees with me 🙂 ). Seriously, I have been showing similar examples for a couple of years, now: http://www.esnips.com/HomeAction.ns;jsessionid=CF4AB47958F72DAAC629988AA31E2B7F
The idea that the “greenhouse effect” has a lag is ridiculous. If the greenhouse gases are increasing “downradiation” they HAVE to be doing it almost instantaneously whenever the sun is out and there are no clouds. Therefore, a humid tropical area, which has the maxium amount of greenhouse gases (primarily HOH) should, according to AGW’s silly radiation-heating hypothesis, be MUCH hotter than a desert at the same latitude and elevation. The reverse is true. In fact, it is rare for any area over water to get much over 33 C; whereas deserts commonly get over 50 C.
Think about it for a moment. On a clear day at high noon in the summer on most parts of the globe, the measured solar insolation is around 1,000 w/m^2. If you assume blackbody radiation, the associated temperature in a greenhouse with that amount of insolation should be around 91 C. Which is about what happens. If you add ANY so-called “backradiation” from greenhouse gases, the temperature in the greenhouse (assume the glass is transparent to IR) should be much higher. It never is. Even if you assume the average 324 watts given by K&T, the temperature would be 117 C!
Also, the positive water vapor feedback idea is silly, because it would lead to a runaway heating on a clear day in humid areas, even if there were no CO2. The water vapor would feed back on itself in a never ending cascade.
The thing that is really exploding the AGW/CO2/WATER FEEDBACK bullshit is the temperature records for the last 10-14 years. Where has all that putative man-caused energy gone? Actual data (as opposed to the AGWers computer models) shows clearly that the oceans are becoming colder. Same with the atmosphere.
We will be in a lot worse condition if it cools 2 C than if it warms 6 C!
Exactly right jae.
RW; not sure what your point is; sudden shifts in climate have occurred just recently;
http://1.bp.blogspot.com/_0oNRupXJ4-A/R0bUzxqFBgI/AAAAAAAAAG4/s8Hpo9G-kSU/s1600-h/Picture+28.png
In respect of the LIA, this NASA paper postulates that a small down trend in insolation can have major climatic effects;
http://www.giss.nasa.gov/research/briefs/shindell_06/
The paper states that a 0.25% reduction in insolation produced regional temperature declines “5-10 times larger” than the global reduction of a few tenths of a degree.
Good morning and thanks for the interest you are all showing in my posted thoughts. Looking through the responses so far there seem to be two that require specific comment from me.
RW; you comment that I totally misunderstand the time constants in the climate system and that at night the temperature does not come anywhere close to equilibrium. I am very well aware that it doesn’t and I never claimed it did. You have missed the point I was trying to make which is that the “green house” impact of clouds is readily discernable to our unaided senses over a time period of a hour or so. The significance is that the “green hosue effect” is not some subtle thing only discerable globally over a period of years to decades but instead is something we can easily experience through our unaided senses over extremely short time periods. I suggested doing the experiment in the evening because clouds have two impacts (as I also mention) they reduce insolation and they inhibit outgoing heat. We don’t feel the latter during the day because the former greatly dominates (which is why I claim increased clouds give nett cooling and are thus a negative feedback term). However if we try the experiment when solar influx is not operating the former effect is easily discernable.
Nick; you make several points. Firstly that the action of water vapour is not a feedback. I totally disagree with you. An increase in energy input to the system (ie: earths surface) causes a rise in temperature and the system responds by changes to its state – some of the liquid water moves to the gaseous phase so as to counteract the increase in temperature. It is not a forcing, it is a reponse of the system to an external forcing which is precisely what a feedback term is. Itis exactly analogous to the action of a buffering agent in a chemical system which is a very clear feedback term promoting stability. Even more obviously, it is also one of the feedback mechanism our bodies use to maintain homeostasis – more commonly known as perspiration. Plants do exactly the same thing.
You then go on to point out that the heat is not lost but is transported laterally and upwards. I have no argument with that and yes I am fully aware of transport of heat through both convection and latent heat effects. The point I was trying to make which you seem to have overlooked is that green house effects are discernable over very short time scales in our local environment. If the positive feedback effect of water vapour was as strong as IPCC are claiming we should experience a massive effect in our local environment and we don’t. Consider, Hansen is claiming we are approaching a tipping point which is another way of saying we are approaching a point where nett positive feedback exceeds 1 so that the system runs away either to destruction or to a point where a new negative feedback term becomes significant enough to re-impose stability at a new equilibrium point. This is supposedly from a very small change in carbon dioxide forcing of about 2 watts/sqM.
Yet in the scenario I talk about the forcing is 90 wattts/sqM, there is a huge change in water vapour firstly from the 8C rise in temperature and then from the massive increase in humidity. This should take us far over the tipping point in a local region. One should experience that as a massive and increasing radiant flux burning us more and more as the humidity rises and we should see thermometers soar. We don’t, in fact we see theopposite with tenmperatures plateauing. Of course you can claim thats all becuase the heat is flowing away sideways but what about calm still days where there is no wind nor even much of a low to cause an updraft. We don’t experience run away on those days either. You might argue that the heat is all going into evaporating still more water but the humidity is often not increasing significantly for several hours so that cannot be the case.
I am suggesting that green house effects are easily discernable on a local short term basis to our unaided senses and to very simple instrumentation such as thermometers. We can use this fact to get at least an empirical check on some of the green house claims and when we do so we find very good reason to doubt the claims. This should ring very large warning bells in our minds.
As an inteersting exercise – can you think of any natural stable system which exhibits clear NET positive feedback? I and some collegues had a go at this a little while ago and could not think of any. Maybe you can do better if so please let me (and others on this blog site) know. If not, what makes us think that climate exhibits massive net positive feedback.
Cheers
Nick Stokes:
“Louis
Based on incontrovertible theory. Latent heat does not leave the Earth. Wind does not leave the Earth. The only heat energy that leaves the Earth is IR radiation. And that only leaves in response to elevated temperatures.”
Jan beat me to it.
SJT you d…….d, most of us do not dispute the greenhouse effect, only the significance of the role of co2 in the effect. We know without it the planet would be uninhabitable.
SJT you d…….d, most of us do not dispute the greenhouse effect, only the significance of the role of co2 in the effect. We know without it the planet would be uninhabitable.
G&T say there is no greehouse effect. Can we all discard G&T now?
Michael Hammer
Hansen’s belief in a thermal tipping point derives from his PhD work on the Venusian atmosphere decades ago; he studied under Carl Sagan.
The idea that Venus is hot because of a run-away greenhouse effect can be traced to Sagan and others some decades ago when the first Venus probes showed that Venus was indeed hot as Velikovsky deduced from historical data – his interpretation being that Venus was a young newly formed planet.
However as Velikovsky could not possibly be right, an alternative explanation was needed and the runaway greenhouse CO2 effect proposed. It bears repeating that prior to the Venus probe data, Venus was supposed to have a similar climate to Earth, our sister planet.
However the Venus runaway greenhouse explanation was not based on in situ experiment but a deduction, using existing knowledge, to explain its thermal state. By sheer dint of argument from authority the runway greenhouse hypothesis became accepted as a factoid.
Hansen’s understanding of CO2 and its greenhouse effect dates from that period in and it is the reason why AGW adherents assume CO2 will produce a net positive feedback, via water etc.
You, and others have shown this to be wrong here on Earth. The implication is that if so, then so also Venus, and that raises the spectre of Velikovsky’s ghost. If questioning AGW causes apoplexy in mainstream science, expressing any interest whatsoever in Velikovsky causes bouts of acute heated apoplexy.
This is why Hansen believes what he does – his science has become detached from its empirical roots and is dominated by the deductive method. It is based on the deduction that Venus is hot because of a runaway greenhouse effect.
What if this initial assumption is wrong?
Louis – Hansen also has another factor motivating him 😉
janama: Oh, give me a break. If you believe this completely, you should commit suicide for the betterment of the Planet.
“However as Velikovsky could not possibly be right,”
Velikovsky? I think that blur you just saw was Mr Hammer running away as fast as he could from Louis.
jae – Dr Hansen was a signatory to the posted proclamation. It came from this paper.
Annual rainfall (I believe this is from Trenberth’s energy balance
paper) = 1m/year
Latent heat flux = 1000kg/m2*2.26MJ/kg/3600/24/365= 71.6 W/m2
The forcing for water vapor is supposed to be about 15 watts for a
doubling.
The increase in temperature from from a doubling of CO2, without
feedback, is acknowledged by everyone to be about 3.8 watts/m^2, which
would result in an increase of around 1C. I’ve seen actual estimates
ranging from 0.7 C to 1.2 C. With a 1C increase, the saturation level
of water vapor would increase 7%. That 7% increase implies a
[(ln 1.07)/(ln 2)] * 15 watts = 0.0677/0.6931 = 1.47 watts/m^2.
If there was NO increase in precipitation, NO change in convection, No
change in clouds, this would result in a temperature of about [(3.8 +
1.47)/(3.8)]* 1C
= 1.39 C.
Trenbeth’s figures give about 390 watts in heating the surface
directly, 22 watts convection, and 78 watts in latent heat, somewhat
higher than my computed estimate of 71.6 watts/m^2. Climate models
predict an increase in precipitation less than the increase in
humidity, around 3% rather than the full 7%.
Multiplying my 71.6 watts by that 1.03 increse in precipitation gives
73.75, for an increase in watts of 2.1 in latent heat of
vaporization. The net increase in SURFACE flux with a doubling of CO2
and water vapor feedback would be
3.8 + 1.39 -2.1, or a DECREASE of 0.71 watts compared to CO2 alone!
I’d suspect there’d also be an additional reduction factor due to clouds. About 30% of
incoming radiation is reflected away by clouds. With rain increasing 3%, wouldn’t clouds also increase, driving the reflection up to 0.309?- Maybe not,
maybe the rain only increases at night.There would be more heat in the atmosphere due to water vapor, an extra 1.39 watts, but more than that 1.39 watts
would be eaten up in LATENT heat, which clouds would radiate away into space.
I think an additional factor would be a decrease in cloud levels at night. Suppose the current temperature is 20 C, and the humidity is 52% , I’ll round up to 7.37g /kg mixing ratio. If that’s the case, air can rise dry adiabetically for 1 dynamic kilometer, where the temperature will drop 10K, hitting the condensaton level and at that point the lapse rate will be 5.39 K/ dynamic km.
Now let the area warm to 30 c. If the humidity is still 52%, you get 14.37 g per kg mixing ratio. That 14.37 is more than 14.2, so the more moist vapor will condense at a lower level. the actual relationship is closer to exponential than linear, so you’d be overestimating the condensation level by computing it as 14.2/14/37 = 0.988 G km, at which point the moist lapse rate will drop to 4.4 C/ G km. In summary, evening temperatures will be higher so there’ll be relatively more water vapor in the atmosphere. That exponential increase of
water vapor in the atmosphere with increase in temperature also acts 1/exponentially in hitting the condensation level. Clouds at night will be radiating heat to space from lower levels, and at higher temperatures during the evening hours.
Incidentally, a real life experiment in increasing water vapor has already been done, in the California central valley.
http://ams.confex.com/ams/pdfpapers/68739.pdf
As a result of irrigating the desert, daytime temperatures DECREASED slightly, nighttime temperatures didn’t fall as much, leading to a slight overall warming, with relatively cooler days and warmer nights.
Louis; You raise a very interesting point that warrants some debate. I have heard the comment about thermal runaway on Venus many times and it seems to me it overlooks the obvious. Most systems sit at an equilibrium point. This is a point where all forces balance so the net force goes to zero. There are in fact two types of equilibrium points, one where any displacement generates a force which pushes the system back towards the equilibrium point, this is stable. The second is one where a displacement pushes the system further away from equilibrium – a pencil balanced on its tip is a good example. Clearly this is an unstable equilibrium point.
Now consider a system which has say two stable equilibrium points with an unstable equilibrium in between the two. You sit at the first stable point and a displacement pushes you back towards it. But if the displacement is so large that it carries you through the unstable equilibrium point then the sign of the feedback reverses and pushes you further away from the original equilibrium and towards the second equilibrium point. Of course if there is no second equilibrium point it pushes the system to infinity.
A tipping point is simply an unstable equilibrium point. What the AGW proponents are suggesting is that earth’s climate has an unstable equilibrium point extremely close to the stable operating point. So close, that a change in input of just 2-3 watts/sqM will take us beyond it. I find it exceptionally difficult to believe that the climate could have remained conducive to life for billions of years if that were the case.
Now for the case of Venus. People seem to assume that for it to be as hot as it is there must have been thermal runaway ie: it must have gone through an unstable equilibrium point. Why make such an assumption? Why not consider that Venus has a simple stable operating point and it is sitting at it? Because we assume the stable point would be an Earth like temperature? We have absolutely no reason to think that. Consider;
Venus receives about 2 times the energy from the sun that Earth does, that should make it hotter for a start. Then even more significantly, its atmospheric pressure is about 90 times higher than Earth and most of this atmosphere is green house gas compared to a very small fraction on Earth. The carbon dioxide concentration is around 100,000 times as high as on earth. Even with a logarithmic relationship, a factor of 100,000 becomes significant . Then most significantly as temperature rises, according to Planks law, the energy radiated moves to shorter wavelengths and carbon dioxide, water vapour and other GHG absorb very strongly indeed at these shorter wavelengths. CO2 has huge absorption bands at 2 and 4 microns which will be massively pressure broadened at 90 bar to something approaching a continuum or black body absorber. This means the greenhouse effect is going to be much much stronger. All this means the equilibrium temperature has to be substantially higher than for earth and it is. Why assume a runaway effect, this is just the natural equilibrium point given the planetary conditions. ?
Sure if we somehow siphoned off 99% of Venus’s atmosphere the temperature would come down but maybe Venus is too close to the sun to ever get to earth like conditions. There is research suggesting a viable range of distances from the sun for a life bearing planet and from memory I think Venus was outside the range.
No thermal runaway, just the natural equilibrium point for a very different set of planetry considitons.
Cohenite,
Take another look at the Shindell paper. Co authors include G.A Schmidt and M.E. Mann. Looks like another attempt to deny *global* effects of the sun. This time it is cooling not getting rid of a *global* MWP. Also takes no account of the cosmic ray theory.
Anything by Schmidt and/or Mann is suspect, IMO.
Yeah, I know Eyrie; I use the paper simply because it at least acknowledges a LIA, even if regionally; it also has ramifications for GMST; if sufficient regions are anomalously low and other regions only slightly low or steady a lower GMST will still be produced which may or may not reflect changes in radiative flux; for example, a large reduction in temperature in cooler areas will produce an overall large anomalous down trend in GMST without a commensurate decrease in IR flux because this was already lower in the cooler regions.
Michael,
Quiite – Venusian temperature is quite easily explained as you detail and does not need a runaway greenhouse effect – it’s location being adequate to explain its present thermal state.
Hence the idea that earth could end up like Venus based on the fallacious runaway greenhouse effect if we keep emitting more CO2 is thus equally fallacious.
The other opinion of the Greenhouse effect by Hans Schluter (pdf linked earlier on this thread) shows this as well.
It is ironic that the intemperate reaction to Velikovsky’s hypothesis, that resulted in the creation of a factoid, was then used to lend authority to the current AGW belief of a human induced tipping point from CO2 emissions.
Our future is the thermal hell on Venus if we keep burning more oil and coal and gas!
No, not based on observation and measurement.
“Hence the idea that earth could end up like Venus based on the fallacious runaway greenhouse effect if we keep emitting more CO2 is thus equally fallacious.”
If you bothered to look up the consensus, you would realise there is no claim being made of runaway AGW. A waste of time arguing against it.
You would also note MH neatly sidestepped Velikovsky.
The actual water vapour data available shows that humidity is, well, a constant entity.
This data is from the radiosondes (and has consequently been discredited by the pro-AGW crowd) but newer supposedly more-accurate data show almost exactly the same trends.
There has been a very small increase in humidity at the lowest levels of the atmosphere and declining humidity in the upper levels of the troposphere (where the climate models predict a large increase) but the weighted average is Constant it appears.
In other words, there is NO feedback from water vapour, either positive or negative.
http://img147.imageshack.us/img147/7908/specifichumidity.png
Michael Hammer- Good discussion of Venus. If memory serves, Venus and Earth have similar dry adiabatic lapse rates-
Earth = 9.76 K/km
Venus = 10.47 K/km .
The higher Venusian pressure results in a thicker atmosphere, which together with the lapse rate results in a higher surface temperature. The temperature in the Venusian atmosphere at 1 bar altitude is not much different from the temperature on Earth.
“According to measurements by the Magellan and Venus Express probes, the area from 52.5 to 54 km has a temperature between 293 K (20 °C) and 310 K (37°C), and the area at 49.5 km above the surface is where the pressure becomes the same as Earth at sea level.”
Mars is another example often discussed, but I have not seen much discussion of another planet having a very dense atmosphere and very high surface temperature- Jupiter.
http://burro.astr.cwru.edu/stu/advanced/jupiter.html
Jupiter has a blackbody temperature of about 110 K. However, atmospheric contraction of 1 mm/year is causing additional heating, raising the top of atmosphere temperature to 160 K.
Jupiter is thought to have a liquid rock surface with an estimated temperature of 24,000 K. This is covered by a liquid hydrogen layer at 10,000,000 bar. Total atmospheric column is about 620 miles. Adiabatic dry lapse rate is estimated to be 2 K/km.
Atmospheric pressure seems to be a key determinant of surface temperature. Thee is no need for tipping points or runaway nonsense to explain the existence of these planetary atmospheric conditions seen today.
SJT,
There is no consensus in science, but Hansen’s belief in the Venus situation was a reaction to Velikovsky, nothing more, nothing less.
What has been shown is that an intemperate reaction to wild idea was root of the present wilder idea that AGW will cause a climatic catastrophe on Earth.
As for sidestepping Velikovsky, er, the subject was Venus and the explanation for its thermal state, not Velikovsky.
“What the AGW proponents are suggesting is that earth’s climate has an unstable equilibrium point extremely close to the stable operating point. So close, that a change in input of just 2-3 watts/sqM will take us beyond it. I find it exceptionally difficult to believe that the climate could have remained conducive to life for billions of years if that were the case.”
Wow. Finally, the crux of the matter expressed plainly! Thanks, M Hammer for taking the time to explain the central mechanism of AGW–which has been rendered rather opaque by the IPCC–in language the lay public, like me, can understand.
This debate should be made accessible to every thinking citizen, including those in parliament, now that the science is about to directly effect every one’s daily life in the form of government legislation.
However, I’m disappointed that STJ and many supporters of the AGW hypothesis here seem unwilling to offer any cogent counter-argument addressing Hammer’s points directly.
LOL. The real “bottom line” in all this, as I think Tom Vonk said some time ago, is what Mother Nature shows us (She has already given us 10-14 years to “wise up,” but many fools don’t get it, yet). The AGW freaks will not see anything but propaganda until they are shivering in some hovel somewhere, with their candle in their hand, mumbling about how there used to be enough electricity to go around. Poor people don’t believe in Gaia, and they exploit the Earth. Make me poorer, and I will exploit the Earth more. I will even eat endagered species to stay alive. Gasp! Wake up, Gotham City folks!
““What the AGW proponents are suggesting is that earth’s climate has an unstable equilibrium point extremely close to the stable operating point. So close, that a change in input of just 2-3 watts/sqM will take us beyond it. I find it exceptionally difficult to believe that the climate could have remained conducive to life for billions of years if that were the case.””
There have been several mass extinctions in that time. Life goes on, but the process of adaption and change can be brutal.
In the paper “Falsification of the Atmospheric CO2 Greenhouse Effect within the Frame of Physics” by Gerhard Gerlich a nice description is given about an experiment by Wood in 1909 that proved the the greenhouse effect does not work for ….. greenhouses!
Does anybody know of an actual experiment that demonstrates a greenhouse effect? That is a material transparent to visible light and opaque to some infrared light (around 10 um) is placed over a surface and causes a temperature increase over the same setup using a material transparent to visible light and transparent to infrared. No cheating with models. Only real materials and actual temperature measurements in a setup using sunlight.
Moskolczi claims the only way to increase warming is to increase the actual mass of the atmosphere. His theory says that the increase in CO2 is automatically compensated by a decrease in water vapor at high altitudes where it is most important. This is confirmed by measurements. Surely if the greenhouse effect is so real someone can demonstrate it with actual materials. Wood demonstrated that anything opaque to infrared blocks the incoming infrared from the sun. Greenhouses work by stopping convection.
By the way, the climate lags the orbital geometry by about 1 month. In Minnesota its coldest about Jan 20 and warmest about July 20, one month after the solstices.
“There have been several mass extinctions in that time. Life goes on, but the process of adaption and change can be brutal.”
SJT,
Ya mean like this?
http://www.gemini.edu/node/259
Bit Velikovsky I reckon.
SJT:
As mass extinctions are associated with ice ages one has some difficulty relating these with the current obsession with global warming, sorry, I mean climate change.
What, we are now to expect an ice age from increased emission of CO2??
How many goal posts have you left in your quiver?
Shawn “Isn’t it more accurate to say here, rather than giving back heat when water vapor condenses, increased water vapor decreases the lapse rate, causing radiation to be emitted at a higher altitude(than would OTW be the case)?”
Well, no, my statement is accurate – yours is more complicated. The saturated lapse rate is lower, but requires the air to be saturated. Unless the water does actually condense, it’s just another gas. And the water vapor content at saturation is a function of temperature and pressure, but is not increased by evaporating more water.
So how the lapse rate responds to more evaporation is unclear. It doesn’t cause IR to be emitted at a higher altitude. Actually IR is being emitted everywhere; the GHG effect is to ensure that only the IR emitted at high altitude (in absorbed bands) actually escapes. And then the key thing is that it’s colder there, so emission is less- there’s a “bite” out of the spectrum.
So a lower lapse rate doesn’t change (in itself) the altitude of effective emission, but may cause the air to be warmer there. To that extent it reduces the GE. However, in its GHG capacity, WV blocks IR and increases the GE, so the two things cancel a bit.
So that’s complicated – my simple point is that latent heat cools one place but warms up another – it evens out temperature, but does not remove heat from the system, unless the WV in the air permanently increases.
Eric “If you are going to start a discussion that the GHE is not a factor, doesn’t exist, or is contrary to the first and second law of thermodynamics as some deniers have argued, that is another matter”.
The so-called deniers are not claiming that the GFE (or whatever is causing the warming that leaves the Earth at an average +15 C) contradicts the 2nd law, they are claiming what Michael describes in the article is contradicting it. The notion that CO2 traps heat, then re-emits it to the surface, creating a positive feedback loop, is sheer nonsense. Since the CO2 is warmed by IR from the surface, the heat it back-radiates would have to warm the surface to a temperature higher than what it was when it warmed the CO2. That represents an amplification of heat that would be required to create a positive feedback loop in such a closed system. That is what contradicts the 2nd law.
Two scientists have commented on this. One was the engineer Jeffrey Glassman who claimed Gavin Schmidt of NASA GISS and realclimate.org did not know what feedback is. The point to note is that Schmidt fumbled badly in trying to explain feedback by offering a mathematical equation that did not describe feedback adequately. He described it subjectively and loosely, failing to explain the gain (amplification) required to create a positive feedback loop.
If Schmidt doesn’t understand feedback, neither does Hansen. Roy Spencer thinks they don’t understand it either. He has measured the effect of water vapour and it has a sign opposite to what modelers like Schmidt and Hansen are using in their GCM’s. Then again, Schmidt is a mathematician and Hansen an astronomer.
http://www.rocketscientistsjournal.com/2006/11/gavin_schmidt_on_the_acquittal.html
The other scientists are Gerlich and Tscheuschner.
http://arxiv.org/pdf/0707.1161v3
On page 77, they take Stephen Rahmstorf, an IPCC reviewer, an AGW advocate and realclimate contributor to task:
“The use of a perpetuum mobile of the second kind can be found in many modern pseudoexplanations of the CO2-greenhouse effect. Even prominent physicists have relied on this argumentation….”
“The renowned German climatologist Rahmstorf has claimed that greenhouse effect does not contradict to the the second law of thermodynamics:
[Rahmstorf quote] ” “Some `sceptics’ state that the greenhouse effect cannot work since (according to the second law of thermodynamics) no radiative energy can be transferred from a colder body (the atmosphere) to a warmer one (the surface). However, the second law is not violated by the greenhouse effect, of course, since, during the radiative exchange, in both directions the net energy flows from the warmth to the cold.”[unquote]
“Rahmstorf’s reference to the second law of thermodynamics is plainly wrong. The second law is a statement about heat, not about energy. Furthermore the author introduces an obscure notion of “net energy flow”. The relevant quantity is the “net heat flow”, which, of course, is the sum of the upward and the downward heat flow within a fixed system, here the atmospheric system. It is inadmissible to apply the second law for the upward and downward heat separately redefining the thermodynamic system on the fly”.
That’s exactly what the AGW crowd do. They include the solar heat twice. The surface is warmed by broad-spectrum solar radiation in the first place. Then the surface and atmosphere are treated as a closed system with positive feedback, in which a subset of the broad-spectrum radiation warms the atmospheric GHG’s. G&T seem to be claiming that the upward and downward heat ‘within that system’ are governed by the 2nd law, and under that constraint, there has to be a loss in the cycle, not a gain as required by positive feedback. Heat has to travel through a medium (air) to get to atmospheric gases and they in turn have to travel back through the same medium. Air acts like an insulator to heat flow, not an amplifier.
The AGW crowd are adding energies to that closed system heat, like the incoming solar radiation. That’s twice it has been added. You can’t do that because there’s a time constraint. The solar radiation that initially warmed the surface is not the same energy that is being falsely added a second time. That second lot is to keep the surface at the temperature it was, otherwise it would cool. You can’t use that second quantity to both warm the surface and act as a positive feedback. Besides, the Sun’s energy is not part of the closed system. IMHO, they are getting lost in the math instead of examining the real physical nature of the system. Then again, what do I know?
As if that’s not bad enough, in the textbook, Fundamentals of Atmospheric Radiation, they claim that scenario, of GHG’s warming the surface, has only ever been accomplished in models. There is no way to measure the effect directly and NASA has admitted that. The positive feedback is a theory, and a bad one at that. As far as GHG’s trapping heat, slowing it down…whatever…The FAR textbook claims that is rubbish. As they put it, photons of heat from the surface cannot be viewed as truant school children being corralled by the GHG’s acting as a truant officer. They are saying the physics involved is far too complicated and G&T agree.
That’s the issue in a nutshell. AGW climate scientists come across as a load of hackers who simply don’t understand basic physics. They have no proof for their theories other than wild conjectures based on computer model theory. I read a debate between Rahmstorf and Lindzen and the first thing that struck me about Rahmstorf was his willingness to introduce emotional claims into the argument. Schmidt is famous for that, going so far as to ban Steve McIntyre from commenting at realclimate. Hansen is another case altogether, with his tipping point theory and ‘throw the skeptics in jail’ ploys.
Alan MacIntire; I just went through your analysis and it is really interesting. Others reading this, please take the time to go through Alan’s work. Of very particular interest is your point that with higher surface temperatures the humidity of rising air reaches saturation at a lower altitude which in turn means clouds will form at lower altitudes. I confess I had not realised that point but it seems very valid. If the clouds are lower they will be warmer and thus radiate more energy to space. Another related point which Nick quite rightly made now a couple of times, the energy absorbed in evaporating water is released again as the water condenses. if one is transporting more water vapour upwards, and it condenses as lower altitude the energy density will be greater which should reduce the lapse rate slightly for the lower troposphere (if I understand your work correctly, I think that is the basis for the change in moist lapse rate you quote from 5.39 to 4.4 C/dynamic km). This of course would further increase cloud temperatures and increase cloud radiation to space. This indeed is a further negative feedback term I had not realised.
I did have an earlier post on this website (3rd March) and in both the paper and especially the subsequent blog discussion, the issue of clouds was raised and according to my calculations they contribute very significantly more energy radiation to space than credited in the K&T model.
Good summary Gordon; the AGW crew would argue that the second law is not compromised because the AGW effect is a delaying one; the ‘blanket’ that spruikers talk of, but there is no storage or pipeline for heat in the system.
Nick; “my simple point is that latent heat cools one place but warms up another – it evens out temperature, but does not remove heat from the system, unless the WV in the air permanently increases”; I don’t get this; if energy is moved horizontally as latent heat surely this effect occurs;
“Energy balance models suggest that the atmospheric circulation operates close to a state of maximum entropy production. Here we support this hypothesis with sensitivity simulations of an atmospheric general circulation model. A state of maximum entropy production is obtained by (i) adjusting boundary layer turbulence and (ii) using a sufficiently high model resolution which allows sufficient degrees of freedom for the atmospheric flow. The state of maximum entropy production is associated with the largest conversion of available potential energy into kinetic energy which is subsequently dissipated by boundary layer turbulence. It exhibits the largest eddy activity in the mid latitudes, resulting in the most effective transport of heat towards the poles and the least equator-pole temperature difference. These results suggest that GCMs have a fundamental tendency to underestimate the magnitude of atmospheric heat transport and, therefore, overestimate the equator-pole temperature gradient for the present-day climate, for the response to global climatic change, and for atmospheres of other planetary bodies”
from Kleidon et al; the point here is that work uses energy ‘stored’ as latent heat; when the horizontal air reaches the poles energy has been expended; in terms of OLR radiation from the poles has less energy than lower latitudes; this effect actually works against you because if the energy as latent heat was not moved it would have a greater effect at the warmer latitudes; the equilibrium mechanisms simply disprove GW at every turn.
Gordon Robertson; It grieves me very much to haveto disagree with a fellow AGW skeptic but in the interests of getting the science right I feel I have to. There are several ways of seeing the greenhouse effect. One simple way, is to compare the emission spectrum from earth, as measured by the Nimbus satellite, with the black body curve. What you will see is significant notches in the Nimbus spectrum corresponding to the absorption lines of the green house gases. How could that come about if the GHG was not blocking radiation from Earth.
Another view, one can buy insulating material in hardware shops which simply consists of a stack of multiple layers of aluminium foil with a very small airgap between each foil and the next. How could a stack of metal be an insulator? Yet these stacks although very thin are surprisingly good insulators and in fact better than an equal thickness of foam. They work because each layer radiates heat back to the previous layer in an exactly analogous fashion to what I described in my previous posting on 3rd March on this site. This is exactly what you claim is not possible.
Another way of looking at things. Radiant heat is electromagnetic energy as is light, the only difference is the wavelength. So lets imagine we have a torch which emits a beam of light. I can shine that torch at a brighter torch does it stop emitting when I do so? No of course not, the light from the torch I am holding will radiate onto the brighter torch.
The second law of thermodnamics does not say a colder object cannot radiate heat to a warmer object. What it says is that NET heat flow is always from warmer to colder. This is because both objects will be radiating heat to each other but the warmer object radiates more than the colder one so the net flow is from warmer to colder.
Yet another way of thinking of the situation. Explain how a thermos flask works. There is a vacumm between the inner and outer skins so the only form of energy transport possible is radiation and certainly the hot liquid inside will radiate by virtue of its temperature. Yet the outer surface of the thermos flash is significantly cooler than the hot liquid inside so by your position it would not be able to return the radiated energy to the hot liquid keeping it hot.
From my perspective the green house effect is real and does occur but what is very much at question is how large is the sensitivity to changes in energy input. I contend that the climate system is well buffered (ie: lots of negative feedback) and it thus very resiliant towards changes in energy input. So what is at issue is not whether the effect is there but its magnitude.
Gary P; you ask “Does anybody know of an actual experiment that demonstrates a greenhouse effect? That is a material transparent to visible light and opaque to some infrared light (around 10 um) is placed over a surface and causes a temperature increase over the same setup using a material transparent to visible light and transparent to infrared.”
I have to tell you I can think of such an experiment (although with solids not gases). In slide projectors the slide is easily damaged by heat. For that reason it is common to put a heat absorbing filter in the light beam before the slide (its a piece of doped glass) to remove the infra red component. I the process the heat absorbing filter gets very hot and causes the light box to also get hotter than it would otherwise.
The dicroic quartz halogen lamps used in downlights do something similar except that the reflective coating reflects visible light but transmits infrared light so the rear of the lamp gets much hotter than it would otherwise but the light emitted is “cooler”- hence the need for good cooling behind the lamp.
Michael (and Alan)
“Of very particular interest is your point that with higher surface temperatures the humidity of rising air reaches saturation at a lower altitude which in turn means clouds will form at lower altitudes.”
That seems wrong. If the surface and lower atmosphere warm, air of a given humidity will reach saturation at a higher altitude. Now it’s true that the air may pick up more water and become more humid, but that is different. In fact, the first assumption is probably that the gradient of relative humidity would be about the same.
If greater humidity is the result, it could produce lower, warmer clouds. But then there are also more clouds, which then block more of the even warmer ground.
I think the talk of moist lapse rate here is loose. The better term is saturated lapse rate. It applies when the air is saturated and water is condensing. If it isn’t condensing, it behaves as dry air. Only a small part of the profile is saturated.
cohenite “the AGW crew would argue that the second law is not compromised because the AGW effect is a delaying one…”
Bohren, in the Fundamentals of Atmospheric Radiation, called that theory nonsense. That’s good enough for me. The AGW lobby doesn’t explain how gases that make up no more than 2% of the atmosphere can delay anything. They conveniently miss the effect of N2 and O2 which make up 98% of the atmosphere and get their warmth from direct contact with the oceans (Stephen Wilde).
Don’t go away. I just read another theory that the solar wind has a lot to do with warming the planet.
http://www.rocketscientistsjournal.com/2007/07/solar_wind.html
Um…er…Louis…isn’t the solar wind made up of electrons and protons?
Gary P. ““Does anybody know of an actual experiment that demonstrates a greenhouse effect? That is a material transparent to visible light and opaque to some infrared light (around 10 um) is placed over a surface and causes a temperature increase over the same setup using a material transparent to visible light and transparent to infrared.”
Gerlich does such an experiment using glass and rock salt as the boundaries. It’s in the G&T paper that falsifies the GHE.
Hi Nick; Interesting point. If saturation partial pressure is exactly exponential with temperature then you are right that starting from the same relative humidity clouds should start to form at the same temperature. I need to think a bit more about this, also lets hear Alan’s input. On the other hand, if warming leads to higher humidity levels (which it does in the tropics if one looks at summer versus winter conditions) then clouds will form at higher temperature. Warmer clouds would radiate more. Yes more clouds are likely. Which way that goes depends on whether one sees clouds as having an overall warming or cooling influence. My view is that clouds especially low clouds give net cooling through increased albedo effect being stronger than the increased obstruction of outgoing thermal infrared.
Michael, I think you may be getting radiation, & reflection rather mixed up, in your latest example. Quite different effects, not interchangeable.
The idea that water is a feedback at all is overlooked in this discussion; Spencer has added enormously to the nature of water and clouds beginning with this;
http://www.climateaudit.org/?p=2543
Spencer also famously addressed the US Senate;
http://epw.senate.gov/public/index.cfm?FuseAction=Files.View&FileStore_id=e12b56cb-4c7b-4c21-bd4a-7afbc4ee72f3
This was followed by the joint effort with Braswell; Spencer is saying the GCMs have erroneously interpretated stochastic cloud variability, which is a form of non-feedback radiative fluctuation, as some sort of anti-Hurst effect having a predictable and continuous and positive feedback on CO2 forcing, and therefore climate sensitivity; as Spencer says in his Senate address [which should be compared with Hansen’s vainglorious efforts];
“The first method seperates the true signature of feedback, wherein radiative flux variations are highly correlated with temperature changes which cause them, from internally-generated radiative forcings, which are unrelated to the temperature variations which result from them. It is the latter signal which has been ignored in all previous studies, the neglect of which biases feedback dianoses in the direction of positive feedback (high climate sensitivity).”
Clouds effect temperature, and have done so in the past as Kump and Pollard postulate.
Gordon:
“Um…er…Louis…isn’t the solar wind made up of electrons and protons?”
Otherwise known as “electricity”. Most think electricity is flow of electrons and that is correct when it’s in wires.
In liquids there is movement of positive charged particles AND negative in opposite directions.
The movement is freer in the gas phase, and freest in the plasma phase.
The model under discussion here is the same as Dick Lindzen’s – (see WUWT) 30 April guest post. It assumes a simple radiating sun and earth in vacuo with nothing else. Restricted to this scenario I have no quibbles with it.
However given the debate here seems to tip one or t’other way, depending on the efficacy of the numeration of the arguments, strongly suggests we are using the wrong ideas to analyse the problem. This is the Hoyle explanation when a lot of scientists spending alot of money can’t seem to reach a conclusion.
The cosmic ray connection is crucial and is the first step of many to be made.
What bemuses me is the rejection that the earth itself, the solid bit under our feet, is thermally irrelevant. Its the earth”s internal behaviour that seems to power the PDO etc, but no one asks how this is achieved.
Instead think of the sun-earth as an electrical circuit and new insights might be possible.
Very interesting Mr Hammer…. It is rather strange to think that no AGW modeler has thought to go outside and look at their hypothesis at work…?
…. Or more exactly. Try to see their hypothesis at work.
However, it is not that strange when one considers that this topic is not about science, knowledge or climate….. But rather about funding and politics.
My only worry is whether our Democracy is strong enough to allow a debate that acknowledges science, knowledge and climate, so as to turn back the politics of a Green Socialist agenda, that needs the taxes and Emission Trading Schemes to power the bureaucracy it needs to implement that agenda.
It would be lovely to live in a world where Science was done for knowledge’s sake.
…. But alas, we must live with this one…. Which apparently, has a negative forcing for water vapor. Sounds wonderful to me:-)
Reading through and finding MH’s response to GR, one could say some of the opinion here is on solid ground, and “greenhouse” is real. However warmer clouds at lower altitudes radiating more heat to space creating negative feedback is going on to deny greenhouse effects at the surface and on the various vapour layers in between. But since I’m recovering from an internal hot house started weeks back with the help of some JW Red (medicinal only) I could have missed another vital point or two down the thread.
Gordon; having taken a few materials up to their vapour point and in some cases watching spontaneous combustion being controlled entirely by the heat source, I seriously doubt we are going anywhere with these bench tests for GHG feedback at higher than natural temps. Anyway; liquid salt, glass etc is too dangerous.
“Gerlich does such an experiment using glass and rock salt as the boundaries. It’s in the G&T paper that falsifies the GHE.”
If you believe G&T, you have also just falsified Michael Hammers essay. You can’t have it both ways. Either there is greenhouse effect or their isn’t.
Cohenite, testing, testing, anyone out there?
I take it you agree G&T is wrong, there is a greenhouse effect, in fact, Mr Hammer assumes it exists.
Readers may have noticed the most energetic commentator with seemingly boundless subject knowledge. Unfortunately for me at least, there is not one personal observation offered anywhere to back it all up.
Moving on, in R/L yours truly worked extensively with feed back systems of the mechanical and electronic type. IMO we are very loose in applying this vast and growing practical engineering experience with all its terms and expectations to infant disciplines like climate science, Gaia Theory and so on.
Little will, stop stalking me; as for G&T, I am keeping an open mind; you know, where you consider things on their merits rather than according to a didactic ideology; speaking of greenhouse; how much do you think it contributes to the assumed 33C?
Still waiting for a convincing rebuttal from the supporters of the AGW hypothesis in direct response to M. Hammer’s points. Snarky comments only reveal you have no credible response.
Come on, STJ give it a fair go, mate. Welcome, Gavin, I believe you have some expertise in this area, no?
Nick Stokes gave it a go and got a second round response from M. Hammer, and now Nick is in “denial,” talking to himself as if he can’t HEAR YOU.
Hey, Nick, we’re still waiting for you to respond to M. Hammer’s question to you: “Can you think of any natural stable system which exhibits clear NET positive feedback?” I’m just curious.
Michael Hammer said:
“Nick; you make several points. Firstly that the action of water vapour is not a feedback. I totally disagree with you. An increase in energy input to the system (ie: earths surface) causes a rise in temperature and the system responds by changes to its state – some of the liquid water moves to the gaseous phase so as to counteract the increase in temperature. It is not a forcing, it is a reponse of the system to an external forcing which is precisely what a feedback term is. Itis exactly analogous to the action of a buffering agent in a chemical system which is a very clear feedback term promoting stability. Even more obviously, it is also one of the feedback mechanism our bodies use to maintain homeostasis – more commonly known as perspiration. Plants do exactly the same thing.
You then go on to point out that the heat is not lost but is transported laterally and upwards. I have no argument with that and yes I am fully aware of transport of heat through both convection and latent heat effects. The point I was trying to make which you seem to have overlooked is that green house effects are discernable over very short time scales in our local environment. If the positive feedback effect of water vapour was as strong as IPCC are claiming we should experience a massive effect in our local environment and we don’t. Consider, Hansen is claiming we are approaching a tipping point which is another way of saying we are approaching a point where nett positive feedback exceeds 1 so that the system runs away either to destruction or to a point where a new negative feedback term becomes significant enough to re-impose stability at a new equilibrium point. This is supposedly from a very small change in carbon dioxide forcing of about 2 watts/sqM.
Yet in the scenario I talk about the forcing is 90 wattts/sqM, there is a huge change in water vapour firstly from the 8C rise in temperature and then from the massive increase in humidity. This should take us far over the tipping point in a local region. One should experience that as a massive and increasing radiant flux burning us more and more as the humidity rises and we should see thermometers soar. We don’t, in fact we see theopposite with tenmperatures plateauing. Of course you can claim thats all becuase the heat is flowing away sideways but what about calm still days where there is no wind nor even much of a low to cause an updraft. We don’t experience run away on those days either. You might argue that the heat is all going into evaporating still more water but the humidity is often not increasing significantly for several hours so that cannot be the case.
I am suggesting that green house effects are easily discernable on a local short term basis to our unaided senses and to very simple instrumentation such as thermometers. We can use this fact to get at least an empirical check on some of the green house claims and when we do so we find very good reason to doubt the claims. This should ring very large warning bells in our minds.
As an inteersting exercise – can you think of any natural stable system which exhibits clear NET positive feedback? I and some collegues had a go at this a little while ago and could not think of any. Maybe you can do better if so please let me (and others on this blog site) know. If not, what makes us think that climate exhibits massive net positive feedback.”
Michael Hammer “It grieves me very much to haveto disagree with a fellow AGW skeptic but in the interests of getting the science right I feel I have to.”
Likewise and having criticised Eli Rabbett for making incorrect statements like “thermal energy = heat” now you make a similar error I’m sorry to say.
wikipedia is not bad when used as a dictionary
http://en.wikipedia.org/wiki/Heat#Thermal_energy
“Thermal energy is a term often confused with that of heat. … Thermal energy then is often mistakenly defined as being synonym for the word heat. This, however, is not the case: an object cannot possess heat, but only energy.”
You can have bi-directional flow of energy but not of heat so this statement is incorrect
“The second law of thermodnamics does not say a colder object cannot radiate heat to a warmer object.”
A colder object can radiate energy to a warmer object but the flow of heat like the current in a conductor flows only from a high to low potential energy heat only flows from high to low temperature areas. Like electric current which can only do work while charges are moving toward a lower potential unless heat is moving from hot to cold (or from low entropy to high entropy) it can do no work.
The second law when it states heat can only spontaneously move for hot to cod it refers to heat not energy.
Wes, OK how about you trying rebuttal of what I had to say with a bit of content?
But yes, in nature there are many oscillating systems. They have positive feedback, and are unstable when they go into oscillation. But prior to that, you have positive feedback with stability.
For example, if wind blows over power lines, it can excite a resonance and make them hum. You could call that instability, and it is caused by shed vortices sending back acoustic waves which modify the shedding. Flutes etc work the same way. If the wires don’t hum, which they usually don’t, the same mechanism is still operating. There is still positive feedback, but the loop gain has just dropped back below one.
That last illustrates why more examples are not immediately obvious. We tend identify positive feedback by its instability effect. Until you see the instability, you’re not aware of the positive feedback.
Gordon R (02/04, 17:56), do you have a page reference to the book of Bohren (and Clothiaux?) where that claim is made?
What “instability”?
Nick “Flutes etc work the same way.”
Yes Nick I play a flute ( had the same teacher as Don Burrows and Jan Rutter) the pitch is determined by the resonant wavelength of the column but I don’t think there is any positive feedback in play since only ~15% of the energy put into creating a sound is actually converted to sound. I can tell you with absolutely no fear of contradiction that it’s harder work getting a big sound out of a flute and to get the same level as a reed instrument or brass is impossible (I played sax at one stage too).
No in order to show positive feedback you need to show that you are getting real amplification i.e. producing energy in the output at a greater rate that it’s input. Do you think you can do that?
The other thing you need to bear in mind is that systems where there is uncontrolled positive feedback tend to self destruct so they are unlikely to survive for long. A good example is a fire cracker when the fuse runs out.
I play a guitar too and I sometimes use resonance to tune it and I can assure you that the second string does NOT vibrate harder than the plucked string resonance is NOT positive feedback.
Here is resonance at work (not positive feedback)
http://www.youtube.com/watch?v=P0Fi1VcbpAI
That bridge broke even though the energy of the bridges vibrations was less than was actually put into it by the wind. These days they make bridges to be resonant at very high frequencies where there are no natural sources.
Jan,
There is certainly positive feedback, in any oscillating system. When a PA system starts howling, it’s still true that the sound energy out is only a fraction of the power used by the amp. It has to be.
With a flute, you supply an airstream largely free of oscillatory energy. You get out a marked frequency peak. At that frequency, there is much more energy than you put in.
But here’s another, more steady example. Just about any form of combustion. The reaction generates heat; the heat accelerates the reaction. With a Bunsen burner you need a match to get the positive feedback cycle going. Then it settles down to a steady flame. But it needs that positive feedback. If you run the flame through a metal mesh, the heat feedback is removed. The flame is quenched. That’s how Davy safety lamps worked.
It’s visually obvious with a candle. The wax supplies the energy to make the flame hot – the flame melts the wax. The flame is steady, but the feedback is there. If you make an otherwise identical candle out of napalm, you get thermal runaway. If you blow the (wax) candle, you block the positive feedback loop by blowing the heat away. The flame dies.
“Little will, stop stalking me; as for G&T, I am keeping an open mind;”
I’m not stalking you, I’m trying to finish off a conversation you walked out on. Made a change from moving the goal posts, I guess. “Keeping an open mind” is a start, I guess. Just remember, they are in complete contradiction of what Mike Hammer is saying.
Interesting thread here for open thinkers. Have no capacity to contribute in substance, except to oppose SJT’s clumsy attempts to close discussion down by asserting certain things ‘settled’ – very dumb and compartmentalised thinking.
“Hey, Nick, we’re still waiting for you to respond to M. Hammer’s question to you: “Can you think of any natural stable system which exhibits clear NET positive feedback?” I’m just curious.”
If you look at the geological record, the climate is inherently unstable, with wild swings apparent between two extremes. We don’t live in a ‘geological’ time scale, our lives are far too short, so we don’t see it happening.
Nick; your analogies are inappropriate; the feedback for a wax flame is the stored energy in the wax; if you put water on it you douse the flame; apply that thought to AGW.
Nick “here is certainly positive feedback, in any oscillating system.”
Rubbish a pendulum is an oscillating system there is no positive feedback there. Unless you keep pushing it the oscillations will dies away. Not only is not a positive feedback system with the bearing friction and air resistance it is a dissipative system.
A self sustaining oscillating system is a positive feedback system it is also dissipative in order to be self sustaining it must draw on an internal or auxiliary power reservoir and i can guarantee that your amplifier and microphone will draw more power from that source (usually about 100% more for a standard class B amplifier) than the oscillatory output. We had this discussion before about positive feedback or any amplification system requiring an internal power source to provide that extra power over and above the input signal.
“With a flute, you supply an airstream largely free of oscillatory energy. You get out a marked frequency peak. At that frequency, there is much more energy than you put in.”
No Nick there is more energy at a particular frequency than is put in at that frequency but that is conversion due to the resonance the energy input to sustain those oscillations is in the order of 700% more than we get out of it. (I’m listening to Gunilla von Bahr play Pachebel’s as a flute trio :- beautiful It was also played at my graduation). Nick there is no free lunch to be had here I’m sorry and my 45 years or so flute playing stands well and truly behind that If I stop blowing the sound soon stops, immediately in fact.
” The reaction generates heat; the heat accelerates the reaction. ”
Again there is an energy reservoir sustaining that this time chemical.
“The wax supplies the energy to make the flame hot”
Precisely there is that (chemical) power reservoir in the body of the candle.
Reply to M. Hammer
The Wood experiment used a model greenhouses with two types of windows. One had a infrared transparent salt window and the other a infrared opaque glass window. The “greenhouse effect” should have caused the model with the salt window to run cooler as the infrared energy was not trapped. Instead it allowed the infrared energy from sun in and the model with the salt window ran hotter, exactly opposite of the “greenhouse” theory. When he pre-filtered the sunlight with glass (well above the models and open so as to not interfere with convection) the model greenhouses ran at the same temperature. This falsified the greenhouse effect for greenhouses!
A description of Woods 1909 experiment can be found here.
http://arxiv.org/abs/0707.1161v4 page 32 of the pdf.
A model of the greenhouse effect has to have light going in and infrared coming out. The filters you describe have the energy going only one way.
One way to run the experiment would be to use Woods salt window and add a near infrared blocking filter to stop ~1-5um infrared well above the models as Wood did with his glass filter.
This would stop the near infrared from heating the floor of the model greenhouse.
Sigh …
http://www.cosis.net/abstracts/EMS05/00132/EMS05-A-00132.pdf
Water vapor feedback enhances greenhouse forcing in
Europe
C. Ruckstuhl (1), R. Philipona (2), B. Duerr (3) and A. Ohmura (1)
(1) Institute for Atmospheric and Climate Sciences, Swiss Federal Institute of Technology
(ETH), Zürich, Switzerland, (2) Physikalisch-Meteorologisches Observatorium Davos, World
Radiation Center, Switzerland, (3) MeteoSwiss, Zürich, Switzerland,
cruckstuhl@student.ethz.ch, r.philipona@pmodwrc.ch
Unexpected large temperature and humidity rises over the past two decades were recently
observed in Central Europe. Detailed analyzes of temperature changes over all
Europe from 1995 to 2002 show similar monthly evolutions, but large differences in
magnitude with annual means decreasing by -0.2(0.4) °C over western and increasing
by +1.4(0.5) °C over eastern longitudinal zones. Investigations of weather maps show
that the strong month-by-month temperature variations are driven uniformly over Europe
by general weather situations. The large east-west differences however, are considered
as prove that the strong temperature increase in Central and North-Eastern
Europe is neither caused by advection nor by changing general weather situations,
but are related to radiative forcings. Radiation measurements in Central Europe suggest
that anthropogenic greenhouse gases are the initial forcing (+0.35 Wm−2) for the
temperature rise, which is followed by strong water vapor feedback and an increasing
water vapor greenhouse forcing (+0.83 Wm−2). But in areas with a lack of available
water for evapotranspiration, like the Iberian Peninsula, decreasing temperatures are
observed and the large thermal heat sink from the ocean hinders temperature to increase
significantly over oceanic regions. ERA-40 reanalysis integrated water vapor
data show high correlation with surface temperature changes (r=0.84), and confirm
the non-uniform strong water vapor feedback greenhouse forcing.
But if you’re looking for simple empirical evidence you may be disappointed. It’s all dreadfully non-linear.
Barsugli, J.J., Shin, S-I. and Sardeshmukh, P.D. (2006). Sensitivity of global warming to the pattern of tropical ocean warming. Climate Dynamics, 27, 483-492. DOI: 10.1007/s00382-006-0143-7
Abstract The current generations of climate models are in substantial disagreement as to the projected patterns of sea surface temperatures (SSTs) in the Tropics over the next several decades. We show that the spatial patterns of tropical ocean temperature trends have a strong influence on global mean temperature and precipitation and on global mean radiative forcing. We identify the SST patterns with the greatest influence on the global mean climate and find very different, and often opposing, sensitivities to SST changes in the tropical Indian and West Pacific Oceans. Our work stresses the need to reduce climate model biases in these sensitive regions, as they not only affect the regional climates of the nearby densely populated continents, but also have a disproportionately large effect on the global climate.
The area of equatorial ocean to the north of Australia and the east of New Guinea in Dec/Jan/Feb is particularly important.
Something for wes & co on feedback loops models etc
http://www.uow.edu.au/arts/sts/sbeder/STS300/limits/simulations/positive.html
http://global.rmit.edu.au/encyclopedia/gaia_theory.php
http://www.dpi.nsw.gov.au/research/topics/climate-change/projects-modelling
and to Gary P: When did our atmosphere seem solid?
And here’s half a free kick for your Cohers. http://www.cdc.noaa.gov/people/gilbert.p.compo/CompoSardeshmukh2007a.pdf
Water vapour feedback indeed 🙂
To cohenite & co: if you can’t quickly explain why the sea around the East Coast of Australia and probably just about everywhere else is still rising, then I can go back to my bed!
Luke: “are considered as prove”..
“suggest that anthropogenic greenhouse gases are the initial forcing..”
balanced science speak, but AGW conjecture on conjecture as usual.
Are you actually someone with scientific training?
Michael is claiming that his instinct suggests that there is a smaller difference between summer and winter temperatures than he expects, on the basis of the claim by modelers, that water vapor, through the greenhouse effect, is creating positive feedback due to a long term temperature change. His claim is that the positive feedback due to WV should be immediately discernible.
We have to weigh his claim based on instinct, against the more detailed calculations of the scientists who research climate as their life’s work. They include the details that Michael’s hunches are leaving out, such as latent heat of transpiration, and convection into the upper atmosphere, and lateral motion. This is a complex system, and instincts of an amateur in such a situation are likely to be wrong.
If Michael could put his finger on what is going wrong with the models it would help to put the discussion on a more scientific track. This it would probably take the discussion to a realm requiring expertise in modeling, beyond the comprehension of many of the readers and posters on this blog, but I am curious to know what Michael thinks specifically is wrong.
Do the models actually predict a larger difference in summer and winter temperatures than is observed, as Michael claims they should? I haven’t seen the output myself, but I believe that it is unlikely that scientists would tolerate such a basic discrepancy in their models. Based on what I have read of the history, the very first general circulation models got reasonable agreement between the actual and modeled climate.
I also would like to know why Michael sets the feedback at a factor of six. I thought that the total positive feedback due to WV and the other positive feedbacks, including albedo gave a total of 3C instead of 1C for the equilibrium temperature increase due to direct radiative forcing.
Michael seems to rely on his observations on the daily changes in temperature, to claim that the climate scientists have got the positive feedback due to water vapor wrong, and have way overestimated it. Is he saying that somehow, the thermal radiation that should be emitted by water vapor in the atmosphere according to its temperature is not in fact being emitted, and there is something wrong with the fundamental theory of radiation? That is what seems to be implied, but not stated when he says things like:
“…Yet in the scenario I talk about the forcing is 90 wattts/sqM, there is a huge change in water vapour firstly from the 8C rise in temperature and then from the massive increase in humidity. This should take us far over the tipping point in a local region. One should experience that as a massive and increasing radiant flux burning us more and more as the humidity rises and we should see thermometers soar. We don’t, in fact we see the opposite with temperatures plateauing…”
In fact, it seems that my reading has told me that global warming stems mainly from an increase in nighttime temperatures, which is consistent with what one would expect from the GHE with positive feedback from WV.
http://www.waterencyclopedia.com/Ge-Hy/Global-Warming-and-the-Hydrologic-Cycle.html
“..The following seven arguments suggest that the hydrologic cycle already has measurably intensified. First, observed global warming is almost entirely due to an increase in nighttime temperature. Daily minimum temperatures have increased at twice the rate of daytime temperatures since 1950 (roughly 1.0°C versus 0.5°C). This suggests increased cloudiness and/or humidity at night, and increased evaporative cooling during the daytime. (This cooling is analogous to body heat evaporating rubbing alcohol from one’s skin, leaving one’s body somewhat cooled in the process.)…”
Well Laz-machine – as you know you can’t really prove anything – so hey maybe you’re not even a dickhead in reality. But scientific training – mate – I’m just the janitor.
Eric “This is a complex system, and instincts of an amateur in such a situation are likely to be wrong.”
First he is no amateur He is an engineer and most engineers do have training and experience in feedback and control systems which leads to good instincts regarding feedback. Most of us have a very good instinct that tells us that regardless of how well we design the feedback system we are not going to get any of it to work without turning the power on.
Bottom line is that positive feedback in a passive system i.e. one with no internal or auxiliary power reservoir is thermodynamically impossible. We can’t get more out of a system than we put into it.
Jan Pompe said,
“No in order to show positive feedback you need to show that you are getting real amplification i.e. producing energy in the output at a greater rate that it’s input. Do you think you can do that?”
Definition of feedback:
http://www.answers.com/topic/feedback
the process in which part of the output of a system is returned to its input in order to regulate its further output
The mathematical definition of positive feedback is as follows
O=g*I +f*O
where O is the output, g is the constant of proportionality between the input, I and the and f is the fraction of the output that is fed back to the input by the return loop. As long as this fraction is less than 1, the system will be stable and not run away.
Clearly if O is quantity of energy , since cannot be created or destroyed, the feedback mechanism must have a source of energy to increase the output by a factor f*O.
In the case of a microphone and amplifier system, clearly the amplifier is plugged into an electrical energy source and a portion of the sound from the speakers will come back into the microphone and be amplified again.
In the case of the earth/atmosphere system, and the temperature feedback mechanism, the source of the energy is the sun. Energy is constantly arriving from the sun, and leaving. The energy to increase the earth’s temperature is obtained by a feedback mechanism which reduces the rate at which energy from the sun exits.
It cannot therefore be argued that conservation of energy prevents positive feedback for temperature increases.
This argument is yet another piece of spaghetti thrown against the wall that will not stick.
“Shawn “Isn’t it more accurate to say here, rather than giving back heat when water vapor condenses, increased water vapor decreases the lapse rate, causing radiation to be emitted at a higher altitude(than would OTW be the case)?”
Well, no, my statement is accurate – yours is more complicated. The saturated lapse rate is lower, but requires the air to be saturated. Unless the water does actually condense, it’s just another gas. And the water vapor content at saturation is a function of temperature and pressure, but is not increased by evaporating more water.”
Uh, perhaps I should’ve said the overall lapse rate, but IAC, if a parcel of unsaturated air rises far enough, it will eventually cool until it reaches it’s saturation level, at which time it will drop to a lower lapse rate, which will then continue to cool more slowly, and ultimately, raise the level at which the heat is emitted.
Isn’t the primary reason the lapse rate for moist air is less than the lapse rate for dry air is because the condensation of water in moist air heats the air around it? The more condensation takes place the warmer the air stays and, thusly, the temperature stays higher longer, and emits more radiation from a higher altitude. More evaporation means more condensation(for the climate to be in equilibrium).
“So a lower lapse rate doesn’t change (in itself) the altitude of effective emission, but may cause the air to be warmer there. To that extent it reduces the GE. However, in its GHG capacity, WV blocks IR and increases the GE, so the two things cancel a bit.”
I actually agree pretty much with this statement, so perhaps I am misunderstanding your point. I thought you were saying that all the energy from evaporation was returned to the surface(as though evaporation didn’t make any difference to the budget).
However, personally, I am not so sure that we know whether they cancel a bit or a lot.
“So that’s complicated – my simple point is that latent heat cools one place but warms up another – it evens out temperature, but does not remove heat from the system, unless the WV in the air permanently increases.”
??? If the WV doesn’t permanently increase, neither does the increased GH effect from the WV.
Cheers, 🙂
Shawn wrote,
“??? If the WV doesn’t permanently increase, neither does the increased GH effect from the WV.
Cheers, :)”
You are confusing short term events with long term averages. The residence time of water vapor is the order of days. So water vapor which removes heat from the ocean or other body of water as it evaporated releases that heat to the atmosphere in a matter of days and returns to the surface as liquid or solid.
Over a period of years, if the average WV content of atmsphere has increased, the amount of energy required to do this is a negliible fraction of the total heat entering the earth system, from the sun, over that period of time.
The increase in average WV content over the years will certainly cause an increase in the GHE.
Eric, your response makes no sense to me, unless you think that “permanently increased WV”(from Nick’s post) means water vapor that is evaporated but not condensed. Since this is physically impossible IMO, I won’t argue the point.
IAC, your argument that energy to increase WV is “negligible” is inaccurate. A 7% increase of WV from a given forcing *requires that that forcing continue to act at that level*. If the forcing disappears so does the increased WV. It doesn’t ever become negligible.
Cheers, 🙂
from Gavin: “and to Gary P: When did our atmosphere seem solid?”
It seemed solid when some people put up sketches in various articles showing radiation being absorbed and emitted by various layers of the earth and atmosphere and did not include convection. If there’s no convection then it is solid.
OK, I agree that a little model greenhouse is very crude. But Wood showed in 1909 that the so called “green house effect” is not true for green houses. I am now wondering can a simple physical model even be built? The atmosphere is too complex to make a rigorously proven model. Did we even include the right phenomenon? Who expected the solar modulated cosmic ray flux to become important? A small physical model would be useful and if one cannot be built we may be missing something fundamental. Michael Hammer in his last post here described some of the issues with broadening of the absorption bands with pressure. I had not seen that discussed before. Glass and salt plates being solid will have broad band absorption and may indicate the importance of broadening of the absorption bands. A small working physical model, or the impossibility of such, may indicate what we are missing.
I have been humbled too many times in the lab by real data destroying my wonderful theory to be concerned about having a theory shot down. I look forward to a delicious meal of crow when a working model green house is demonstrated.
“RW; you comment that I totally misunderstand the time constants in the climate system and that at night the temperature does not come anywhere close to equilibrium. I am very well aware that it doesn’t and I never claimed it did. You have missed the point I was trying to make which is that the “green house” impact of clouds is readily discernable to our unaided senses over a time period of a hour or so.”
Actually what you said was this: “Maybe the thermal mass of the environment averages out much of the summer winter difference? Unlikely, consider the significant temperature change between day and night. If the temperature can change significantly in a few hours it could certainly change profoundly over 6 months”
This can only be read as saying that because it gets colder at night, then over six months the climate system must reach its equilibrium response. The logic is faulty, and the conclusion is wrong.
Louis Hissink – apparently you believe that Venus came out of Jupiter and was a comet and caused catastrophes on earth and is now a planet. If I were Ms. Marohasy I would block you from commenting here; you’re an embarrassment to yourself, and all who do not dissociate themselves from you.
Eric Adler:
Jan Pompe also said:
“Bottom line is that positive feedback in a passive system i.e. one with no internal or auxiliary power reservoir is thermodynamically impossible. We can’t get more out of a system than we put into it.”
Which is correct. The spagetti sticks fine.
Eric:
You say:
“In fact, it seems that my reading has told me that global warming stems mainly from an increase in nighttime temperatures, which is consistent with what one would expect from the GHE with positive feedback from WV.”
Er, Eric, there has been no statistically significant “global warming” for about 14 years. Where oh where is all this extra radiation and feedback from the CO2/HOH system being stored? Could there maybe be something wrong with the whole hypothesis?
Comment from: Shawn H April 3rd, 2009 at 3:11 am
“Eric, your response makes no sense to me, unless you think that “permanently increased WV”(from Nick’s post) means water vapor that is evaporated but not condensed. Since this is physically impossible IMO, I won’t argue the point.
IAC, your argument that energy to increase WV is “negligible” is inaccurate. A 7% increase of WV from a given forcing *requires that that forcing continue to act at that level*. If the forcing disappears so does the increased WV. It doesn’t ever become negligible.
Cheers, :)”
Apparently you don’t understand the difference between radiative forcing and a temperature increase. The average water vapor level is maintained by an increase in average temperature.
So if equilibrium occurs at a higher average temperature, no radiative forcing is required to maintain the WV at a higher level than before. At equilibrium, radiative forcing is zero.
# Comment from: jae April 3rd, 2009 at 4:42 am
JAE wrote
“Eric Adler:
Jan Pompe also said:
“Bottom line is that positive feedback in a passive system i.e. one with no internal or auxiliary power reservoir is thermodynamically impossible. We can’t get more out of a system than we put into it.”
Which is correct. The spagetti sticks fine.
# Comment from: jae April 3rd, 2009 at 4:47 am ”
My objection to this argument was made clear in the rest of my post, which you obviously didn’t read, didn’t understand, or are purposely ignoring.
The source of energy to drive the additional feedback is solar radiation. One merely needs to prevent some solar energy from escaping after it has been absorbed by the system to get the energy needed for the feedback mechanism. To increase the average amount of water vapor stored in the atmosphere by a few percent over a period of years takes only a small fraction of the energy arriving from the sun over that period of time.
The first law of thermodynamics is not violate by the WV feedback mechanism. To think so is to believe that you are incredibly more competent than the climate scientists that have devoted their working lives to this subject. I believe that it is more likely that you are overestimating your own competence in this field. You could start improving your competence by reading what others have written.
“IAC, your argument that energy to increase WV is “negligible” is inaccurate. A 7% increase of WV from a given forcing *requires that that forcing continue to act at that level*. If the forcing disappears so does the increased WV. It doesn’t ever become negligible.
Cheers, :)”
Apparently you don’t understand the difference between radiative forcing and a temperature increase. The average water vapor level is maintained by an increase in average temperature.
So if equilibrium occurs at a higher average temperature, no radiative forcing is required to maintain the WV at a higher level than before. At equilibrium, radiative forcing is zero.”
Eric, you seem to be using an idiosyncratic definition of the word forcing – here is a typical definition. “The radiative forcing of the surface-troposphere system due to the perturbation in or the introduction of an agent (say, a change in greenhouse gas concentrations) is [b]the change in net (down minus up) irradiance[/b] (solar plus long-wave; in Wm-2) at the tropopause AFTER allowing for stratospheric temperatures to readjust to [b]radiative equilibrium[/b], but with surface and tropospheric temperatures and state held fixed at the unperturbed values.”
Radiative forcings are not zero at equilibrium. A continual forcing of some sort is necessary to *maintain* WV at a higher level than would OTW be present. If a forcing increases the temperature and the water vapor, then for that higher level of WV to persist the forcing must also persist.
Cheers, 🙂
Several posts overnight require more comments: 1) Engineers alone, are allowed to work with instincts in my book. 2) imo Jae for one has still not faced the SL issue in regard to the extra energy stored in the system. 3 ) Jan should be thinking of those few practical cases where we have just turned the power off and more frequently when plasma naturally grounds our power grid. 4) System shock needs to be factored in.
For Gary P: Since much of my early practical experience was gained in a paper mill complex of heavy industry I could say a lot about “small” models versus the real situation however I will relate a story about a former policeman I once worked for as a freelance salesman.
This guy was apparently a legend in the Nu Swift Co, but former clients lunching by the potato shed gave me this yarn about the day his demo failed. His home grown sales procedure was to place a 20 pound note in a tray of petrol in front of the lads on their smoko break then carefully light the fumes.
For those who don’t know, the British patented Nu Swift dry powder fire extinguisher was a beast and a half at its best but one could use it puff by puff over a month or two. One day at the farm yard he was actually right out of powder and the story goes the pure gas blew fire, note and petrol into the crowd.
Oddly enough they were more amused than abused by his antics in catching that dammed flaming note still fluttering round in the scramble.
There is a lot more we can say too about closed systems versus open systems when it comes to understanding feedback.
In general; there is no point in anyone reading what experts have written if they are not going to “go with the flow”
Eric’s appeal to authority (a well-known logical fallacy):
“The first law of thermodynamics is not violate by the WV feedback mechanism. To think so is to believe that you are incredibly more competent than the climate scientists that have devoted their working lives to this subject. I believe that it is more likely that you are overestimating your own competence in this field. You could start improving your competence by reading what others have written.”
Eric, I am just a chemist and certainly no expert and am not trying to be dogmatic. I’m expressing my current understanding, as I trust you are. The problem with your argument, however, is that there are many well-qualified scientists that don’t agree with it (I don’t know just what a “climate scientist” is). As far as I’m concerned, it has not even been established that the increase in CO2–a GHG–has caused any significant increase in temperature, even by itself, without any feedback. The data are showing otherwise, and there may now be more scientists that disagree with the hypothesis than there are who agree with it. Of course, if you were to poll only those scientists that are on the AGW funding gravy-train, you would get something like the IPCC “consensus” (which, of course is anathema to real science).
RW “Louis Hissink – apparently you believe that Venus came out of Jupiter and was a comet and caused catastrophes on earth and is now a planet. If I were Ms. Marohasy I would block you from commenting here; you’re an embarrassment to yourself, and all who do not dissociate themselves from you”.
Maybe you could explain to us where the planets came from. One explanation, from astrophysics, is that planets formed from dust clouds, but no one has offered an explanation as to how the dust condensed into solid spheres, some of which are made up of solid materials like iron, silicates, etc. while other are made up of frozen gases.
It’s easy to be smarmy about the theories of others when you don’t have a clue how anything happened in the first place. The origin of the planets is likely to have an incredulous explanation but it is far more likely they were captured by the Sun’s gravitational field than anything. Over the billions of years in which the solar system formed, it is possible that giant bodies collided, dislodging pieces. Why they are spherical is not in the least plain to me.
Even if they originated outside the solar system, how did they become spherical? How did the Sun become a spherical mass of burning hydrogen and helium? Why is Jupiter a spherical mass of solid gases? Where did those gases come from? If the planets were captured by the Sun, how did they get to the critical speed required to enter orbit rather than spiral into the Sun or be catapulted off further into space?
When you consider the incredible circumstances under which the solar system formed, I don’t see what is so outlandish about the ideas of Louis. I think you could use a little more imagination.
For gavin; what sea-level is doing along the East coast;
http://www.coastalconference.com/2007/papers2007/Peter%20Helman.doc
Eric says the increase in average WV in the atmosphere will increase the GH effect; this is wrong for 2 reasons; firstly the effect of WV at different atmospheric levels has a profoundly different effect; WV at the near surface will produce temperature moderation through increased albedo and evaporative process [evaporation and horizontal convection are not net energy sum processes; see my previous Kleidon post]; less WV at higher levels also is a ‘cooling’ process through expansion of the window; and this is what is happening;
http://landshape.org/enm/are-changes-in-water-vapor-consistent-with-the-models/#comments
luke; fair dinkum; I gave you Compo; now you’re giving them back!? About Philipona’s latest effort; that’ll be included in my next 10 worst so I’ll save it for then.
Shawn Wrote;
“Apparently you don’t understand the difference between radiative forcing and a temperature increase. The average water vapor level is maintained by an increase in average temperature.
So if equilibrium occurs at a higher average temperature, no radiative forcing is required to maintain the WV at a higher level than before. At equilibrium, radiative forcing is zero.”
Eric, you seem to be usin423g an idiosyncratic definition of the word forcing – here is a typical definition. “The radiative forcing of the surface-troposphere system due to the perturbation in or the introduction of an agent (say, a change in greenhouse gas concentrations) is [b]the change in net (down minus up) irradiance[/b] (solar plus long-wave; in Wm-2) at the tropopause AFTER allowing for stratospheric temperatures to readjust to [b]radiative equilibrium[/b], but with surface and tropospheric temperatures and state held fixed at the unperturbed values.”
Radiative forcings are not zero at equilibrium. A continual forcing of some sort is necessary to *maintain* WV at a higher level than would OTW be present. If a forcing increases the temperature and the water vapor, then for that higher level of WV to persist the forcing must also persist.
Cheers, :)”
http://en.wikipedia.org/wiki/Radiative_forcing
You have a problem with comprehension of the word “equilibrium”, in the context of the technical definition that you have quoted. The stratosphere temperatures may be adjusted to radiative equilibrium values after the perturbation, but at the same time the surface and tropospheric temperatures are held at fixed at their unperturbed state. This certainly does not constitute a state where the system is in equilibrium, so it is incorrect to cite this as proof that net irradiance is not zero at system equilibrium.
You need to improve your reading comprehension before you wade into this technical stuff.
Comment from: Gordon Robertson
Eric’s appeal to authority (a well-known logical fallacy):
“The first law of thermodynamics is not violate by the WV feedback mechanism. To think so is to believe that you are incredibly more competent than the climate scientists that have devoted their working lives to this subject. I believe that it is more likely that you are overestimating your own competence in this field. You could start improving your competence by reading what others have written.”
Eric, I am just a chemist and certainly no expert and am not trying to be dogmatic. I’m expressing my current understanding, as I trust you are. The problem with your argument, however, is that there are many well-qualified scientists that don’t agree with it (I don’t know just what a “climate scientist” is). As far as I’m concerned, it has not even been established that the increase in CO2–a GHG–has caused any significant increase in temperature, even by itself, without any feedback. The data are showing otherwise, and there may now be more scientists that disagree with the hypothesis than there are who agree with it. Of course, if you were to poll only those scientists that are on the AGW funding gravy-train, you would get something like the IPCC “consensus” (which, of course is anathema to real science).
What evidence do you have that there are well qualified scientists that believe the positive feedback mechanism proposed as a result of the GHE, violates the first law of thermodynamics? What makes them well qualified? Don’t confuse this question with whether positive feedback is really happening, stick to point about violation of the first law of thermodynamics, i.e. energy is conserved. Where is the data that shows that positive feedback of Temperature increases via water vapor violates the first law of thermodynamics. Where is the evidence that many well qualified scientists believe this?
Do you yourself believe that the idea of postive WV feedback violates the first law of thermodynamics. Show where in the proposed physical process the first law of thermodynamics is violated, by the maintainance of a higher average WV concentration as a result of increased temperature, and the enhancement of the greenhouse effect by WV at the same time.
If you can’t are you saying that I should believe something foolish because somebody says it, even though he could be a fool?
RW
“RW “Louis Hissink – apparently you believe that Venus came out of Jupiter and was a comet and caused catastrophes on earth and is now a planet. If I were Ms. Marohasy I would block you from commenting here; you’re an embarrassment to yourself, and all who do not dissociate themselves from you”.
(Gordon – I completely missed that ad hominem – thanks).
RW: You are quite wrong – I emphatically do not believe Venus came out of Jupiter….
Eric, what are you talking about? What “equilibrium” are you talking about? It clearly isn’t radiative equilibrium, per the accepted definition. It is entirely possible to have a non-zero radiative forcing and be at radiative equilibrium.
IAC, your original claim was that the energy needed to keep the WV at the higher level becomes negligible at some point. It clearly doesn’t.
Cohenite says,
“Eric says the increase in average WV in the atmosphere will increase the GH effect; this is wrong for 2 reasons; firstly the effect of WV at different atmospheric levels has a profoundly different effect; WV at the near surface will produce temperature moderation through increased albedo and evaporative process [evaporation and horizontal convection are not net energy sum processes; see my previous Kleidon post]; less WV at higher levels also is a ‘cooling’ process through expansion of the window; and this is what is happening;”
My understanding is that the GHE is backradiation from trace gases that absorb upward radiation from the earth’s surface. There is no doubt that WV will increase the GHE as defined that way.
If you are going to claim that other processes overwhelm the positive feedback provided by WV and the GHE, you will need to produce a General Circulation Model, which examines all the effects in a quantitative fashion, write a real scientific paper, and provide references which justify the parameters you have chosen to use.
There is no way you can convince anyone with any sense by waving your hands, and spouting jargon in a blog post, which is what you are doing now.
Nick Stokes “For example, if wind blows over power lines, it can excite a resonance and make them hum”.
You’re confusing resonance with positive feedback. Although resonance may incorporate positive feedback as part of its mechanism, it is not positive feedback per se. The kind of positive feedback referenced by AGW climate scientists is one that allegedly amplifies temperature. That amplification is not available in a passive, purely resonant system.
Consider an acoustic guitar. You pluck a string and the string vibrates. So far, there is no feedback, the vibration can be explained by the mass of the string and the tension. With the string mounted above the resonant sound box of the guitar, the sound waves from the vibrating string enter the sound box and contribute to the pre-designed resonance of the sound box, which tends to amplify them. However, amplification is a property of a resonant system ‘at a particular frequency’.
The resonant sound leaves the box and reinforces the vibrating string. There’s your feedback. Left unattended (no more plucking), the vibration will die off naturally. No matter how hard you pluck the string, and no matter how fast you do it, the sytem will never become unstable and run away. That’s because there is not enough external power and not enough positive feedback. There have been examples like the Tacoma Narrows Bridge, which resonated so strongly that it literally tore itself apart. That was entirely due to resonance in the system, not positive feedback with gain.
Now take the case of an electric guitar. It has the same vibrating string, emitting sound waves against a solid guitar body. The body also has a pickup, which has electromagnets that are excited by the vibrating steel guitar string. Those excitations are electrical voltages that are fed to an amplifier, where they are amplified and sent out as higher powered sound waves representing the vibrating guitar string. If the volume is high enough on the amplifier, the sound waves from the speakers strike the solid guitar body and the vibrating string directly. When the waves from the amplifier are in phase with the vibrating string, the string picks up more energy, and that is your positive feedback. It could not operate without the power added from the amplifier’s power supply.
If the output level from the speakers are high enough and the guitar is close enough to them, the system will run away. That is heard as a squealing, sustained note. Guitarists learn to control the feedback, but left unattended it will blow the speakers and/or the amplifier.
For positive feedback to cause a runaway condition in an electronic amplifier, you need three things. The feedback must be in phase with the input signal so as to reinforce it, the magnitude of the feedback must be large enough to overcome losses, and an amplifying device is required to increase the signal on each feedback cycle. An oscillator in an electronic circuit is designed that way, with the most basic form being a ‘tank’ circuit with an inductor and capacitor. The tank works on the principle of a charged capacitor discharging through an inductor, which forms a magnetic field. The magnetic field then collapses and recharges the capacitor. That forms a damped oscillation that will die off due to losses in the tank circuit.
The tank runs in the input circuit of a transistor amplifier and its oscillations are fed to the transistor input. A portion of the transistor’s output is fed back to the input at such a level and in such a phase that it maintains a constant output level. If you increase the feedback beyond that level, the output will run away till there is no more current available from the power supply. Of course, the amplifying device usually burns out by that point.
AGW scientists are claiming the same mechanism is available in the atmosphere, between the surface and the GHG’s in the atmosphere. IMHO, they are making a serious mistake in confusing computer model jargon with the real thing. Feedback and forcing are also terms used to describe a differential equation. The oscillator circuit I described with the tank circuit can be described mathematically using a differential equation, and when programmed into a computer, it can be simulated.
In an earlier post, I gave a link to an article by Jeffrey Glassman, an engineer, who claimed Gavin Schmidt was confused about feedback. Schmidt works for NASA and James Hansen, doing computer modeling. If Glassman is correct, it means that AGW theory at the top end is seriously flawed.
Eric; are you little will? Handwaving? I’ve given you specific references about atmospheric SH levels; I’ve referred you to Kleidon’s paper which addresses and contradicts this idea that conservation of energy means that the ‘delay’ in IR leaving with a constant insolation accelerates GH conditions; it doesn’t as long as that energy is worked within the system; as well, the importance of the decline of WV in the way I described means that energy is not trapped; there are 2 recent papers which address this;
http://jennifermarohasy.com/blog/2009/03/radical-new-hypothesis-on-the-effect-of-greenhouse-gases/#comment-87115
http://met.hu/doc/idojaras/vol111001_01.pdf
You are the proponent of AGW; the onus of proof is on you buddy.
As the self-appointed spokesperson for the silent majority lay audience here, we’re still waiting for a reasonable, point by point rebuttal to M. Hammer’s thesis.
Some of the supporters of the AGW hypothesis have forcefully expressed their disapproval of M. Hammer’s bad habit of thinking for himself, but none have made a rational argument, which falsifies M. Hammer’s hypothesis.
Luke’s links only prove that M. Hammer characterization of water vapour’s role in the orthodox AGW hypothesis is correct and not a strawman. Thanks Luke.
Gavin’s comment, “In general; there is no point in anyone reading what experts have written if they are not going to “go with the flow.” Sums up the thrust of AGW arguments here. M. Hammer must be wrong because the IPCC experts, by definition, must be right. Don’t even dare to think outside the box.
RW’s OT attack on Louis’s astrophysical theories also typify the tact of many pro-AGW comments. They’re looking for anything to draw attention away from their inability to directly and reasonably falsify M. Hammer’s premise…. Hey, Look there’s a possum!
Gary P explodes the myth of GCM reliability: “The atmosphere is too complex to make a rigorously proven model. Did we even include the right phenomenon?” Gee, thanks Gary, wrong thread though. Can I quote you later on that?
Eric Adler has probably made the most valiant attempt to falsify M. Hammer’s hypothesis, but like every other AGW supporter here he pretends he can’t HEAR YOU. “If Michael could put his finger on what is going wrong with the models it would help to put the discussion on a more scientific track.”
Duh, even a lay person can see that Michael put his finger on what is wrong with the AGW model in his first paragraph. Then Eric goes on to explain it’s too hard to explain and we couldn’t possible understand anyway.
“This is a complex system, and instincts of an amateur in such a situation are likely to be wrong….beyond the comprehension of many of the readers and posters on this blog.” Oh, OK, that settles the science then. The IPCC must be right. Case closed.
Personally, I am really disappointed in the ordinary effort made by the AGW supporters here. Like most of the lay audience I have an open mind on the AGW debate. That’s not to say that I don’t have strong opinions, but that as a normally rational, thinking person my opinions are always open to adjustment as better ideas and new evidence emerge.
I’m beginning to wonder if the same can be said of our pro-AGW commenters here?
Eric Adler “My understanding is that the GHE is backradiation from trace gases that absorb upward radiation from the earth’s surface. There is no doubt that WV will increase the GHE as defined that way”.
Eric…think about what you’re saying. The GHG’s in the atmosphere account for approximately 2% of atmospheric density. How can they possibly have the capacity to warm a planet from a theoretical – 19C to +15 C? How about the other 98% comprised of nitrogen and oxygen? The NOAA satellites, from which UAH and RSS make their data sets, measure microwave radiation from oxygen. That means the oxygen is representative of the actual atmospheric temperature. How did it get to that temperature? Nitrogen and oxygen can’t absorb surface radiation, so where did they get their heat? Surely not from the 2% of GHG gases.
On top of that, anthropogenic CO2 accounts for about 3% of all atmospheric CO2 which accounts for 0.03 % of atmospheric gases. How does such a piddly amount of CO2 create a positive feedback with enough magnitude to cause a thermal runaway?
WV is part of a replenishable cycle. Even though it only makes up 1% of atmospheric gases on average, it is being constantly replenished by the oceans and the land surface. As such, WV is part of a large convection cycle. When you compare that replenishment to the replenishment of CO2, their is no comparison. Based on a 380 ppmv density for CO2 and a 0.6% increase in ACO2 per year, Roy Spencer calculated that anthropogenic CO2 increases at 1 molecule of CO2 to 100,000 molecules of air, every 5 years.
The argument that such a tiny amount of ACO2 can increase atmospheric temperature through positive feedback, just doesn’t hold any water vapour.
Eric,
“The energy to increase the earth’s temperature is obtained by a feedback mechanism which reduces the rate at which energy from the sun exits.”
Sorry but this doesn’t make sense, either you don’t really understand positive feedback, or made a mistake, and meant something else?
Wes,
In addition we have one rule in science – if you can’t explain what work you do to your grandmother, then you don’t really understand it yourself.
The ability to describe a scientific idea in layterms means you know what you are dealing with, and Mike Hammer as done that.
The resort to mathematical arcania, or convoluted rhetoric simply means argument from authority – or a flight into deductionist fantasy from which issuance of gibberish occurs.
RW’s (and for that matter Luke before him and SJT in the present) focus on me and a deceased Jewish polymath does indeed seem acts of desparation but as they haven’t any chairs left to rearrange on the Jolly Ship Climate Change, sinking after having hit one of Al Gore’s icebegs, witch-hunting, or in my case warlock, is the standard reaction.
I just hope I don’t end up like Giordano Bruno.
Thanks Wes – at least you’ve moved on to attempting summaries – a small improvement over the normal lack of contribution.
I just find it funny that we’re having this massive theoretical discussion when Rolf has actually measured the disputed effect.
Also humorous for Gordon on the “runaway” scam. http://www.realclimate.org/index.php/archives/2009/04/advocacy-vs-science/
We’ve actually seen evidence of the formation of other solar systems from dust clouds , Gordon.
There are also a lot of extra solar planets that have been discovered in the last 20 years or so. Capture by stars would seem to be very common which doesn’t make sense when you look at the scale of distances involved.
In the early solar system there were many collisions between large bodies. look at the Moon or Mars. Or the theory of the formation of the Moon itself being caused by a collision between a Mars size body and the Earth.
As for why the planets are spherical, there is nothing mysterious about this at all. When the body is large enough the gravitational forces on its material exceed the strength of the material even if it is a solid.
While I’m at it can we please stop this stupid questioning of the ability of infra red absorbing gases to slightly warm the planet? The effect is real and measurable. What is in dispute is the ability of just one of those gases to have a huge effect when the spectrum in which it absorbs IR mostly overlaps that of water vapour and there are huge feedbacks operating as water changes phase. It seems pretty obvious that the water vapour effect isn’t a huge positive feedback because summer…..ends.
Looking at the paucity of evidence for any significant warming (when statisticians are at each others’ throats over interpretation of measurements which may or may not show a fraction of a degree C warming there’s likely nothing much happening) it seems obvious that atmospheric CO2 cannot be doing much even though its concentration has increased by 30% or so.
As for “If you look at the geological record, the climate is inherently unstable, with wild swings apparent between two extremes. We don’t live in a ‘geological’ time scale, our lives are far too short, so we don’t see it happening.”
Yes the Earth does have two large scale climate types in the current epoch. Ice ages and warm periods. We’re in a relatively mild warm period although a geologist of my acquaintance says we’re actually still in an ice age because ice exists at both poles at the same time. Orbital mechanics seems sufficient to explain the currently fairly regular ice ages.
Of course if our lives are far too short so we don’t see it happening maybe we shouldn’t worry but continue to try to increase our understanding of the universe and how it works and develop our civilization to the point where when disaster really threatens we just may be able to do something about it or at least ensure the survival of a significant part of our species.
Eric “The first law of thermodynamics is not violate by the WV feedback mechanism”
Nature who taught us the laws of thermodynamics does not violate them, so whatever feedback there is [it’s negative] does not violate the laws but for your amateurish explanations to be true she would have to make an exception.
“The source of energy to drive the additional feedback is solar radiation.”
NO Eric you can’t count it twice it’s the original signal that you claim the the positive feedback amplifies it can’t also be the auxiliary power reservoir. Restrained power is not extra power thinking that it is, is a serious mistake.
Gordon:
“Eric…think about what you’re saying. The GHG’s in the atmosphere account for approximately 2% of atmospheric density. How can they possibly have the capacity to warm a planet from a theoretical – 19C to +15 C? How about the other 98% comprised of nitrogen and oxygen? The NOAA satellites, from which UAH and RSS make their data sets, measure microwave radiation from oxygen. That means the oxygen is representative of the actual atmospheric temperature. How did it get to that temperature? Nitrogen and oxygen can’t absorb surface radiation, so where did they get their heat? Surely not from the 2% of GHG gases.”
It is certain that the GHGs do aid in thermalizing the bulk of the atmosphere (N2 and O2). CO2 and HOH absorb the IR from the surface and either emit it again or transfers the energy to the other gases via collisions. As I understand it, most of the energy is spread very rapidly by collisions. Of course, the N2 or O2 can then collide with a CO2 or HOH molecule and give some energy back, which can also be radiated. What is important, however is that the whole air-mass very rapidly gets heated up this way each day, and it takes awhile for it to cool off at night. (A great deal of heat is also stored by water). The question is how much do the GHGs retard cooling via “back-radiation.” According to the CO2/AGW hypothesis this is a very important mechanism. However, I can’t help but wonder if it’s not completely overwhelmed by convection, just like when you open the roof and doors of a greenhouse. My questions are closely related to or identical with the points Michael Hammer is making (I think).
luke; I know Philipona is your ace and you assert his latest paper overcomes the manifest deficiencies of his previous papers which I have detailed;
“Comment from: cohenite August 31st, 2008 at 9:23 pm
luke; Philipona’s paper; his measure of longwave down radiation (LDR) is based on the ist derivative of SB; that is the rate of change of the average of the temperature to the 4th power; I have referred to Pielke’s and Motl’s work on the difference between the average of SB and the 4th power of the average temperature before; I know you will say that Philipona’s study counters this because it is regionally based; but that is the point; you can’t generate a global average from in effect regional LTE’s. But the calculation has more pressing problems;
1 Philipona has chosen the period of 1995-2002; he derives his averages as the rate of change over this period, calculated as the annual variation for each year then deducted from each month; a simple linear regression like this is a form of running mean; running means are fraught with problems; they can give false trends in terms of the actual data; ie; 11, 12, 13, 14, 15, 16, 15 , 14, 13, 12, 11 is a sequence of 11 values; including the no 16 in adding the 1st 6 events you average 13.5; after the 15, average 14.6; after 14 average of 14.5 for 6 events; after 13 average of 14.5; the actual values are falling but the moving average is continuing to rise; since I presume each year is treated in discrete fashion, a false trend would be magnified over the full 7 years of data.
2 Philipona uses Hadcrut data anomalies; as you know I’m a fan of base period taint, so to illustrate this here is a graph of Philipona’s data extended from 95-2002 to 95-2005;
http://www.warwickhughes.com/papers/phil9505.gif
I guess the point here is that the first order curve fit can be of limited analytical value. It appears to be a straight line fit through the data, but the slope, or rate of change of that line, is dependent on the starting point, and in this case the finishing line, which is an arbitary decision. As an additional blemish the MSU temperature data for 95-2005 has only 38% of the warming of HadCrut.
3 Philipona says insolation (I presume, as opposed to an aerosol effect which some of his other papers have dealt with) was decreasing during this period; Fig 2.1 here shows this is incorrect;
http://www.pmodwrc.ch/pmod.php?topic=tsi/virgo/proj_space_virgo#VIRGO_Radiometry
4 Philipona extracts from his LDR figure a cloud-free component so as to be able to isolate the GHG source of LDR; there have been some good comments already on this thread about the difficulty of estimating the thermal effect of atmospheric water vapour but I’ll quote from Judith Curry; “Basically the “clear sky” radiative transfer problem is regarded as pretty much solved in terms of radiative fluxes” by the models. “But seperating cloud from water vapor feedback is rather artificial, they are both totally entertwined.”
But, his latest paper is no improvement as I will detail when I do my next 10 worst.
Gordon Robertson says:
“Eric Adler
“My understanding is that the GHE is backradiation from trace gases that absorb upward radiation from the earth’s surface. There is no doubt that WV will increase the GHE as defined that way”.
Eric…think about what you’re saying. The GHG’s in the atmosphere account for approximately 2% of atmospheric density. How can they possibly have the capacity to warm a planet from a theoretical – 19C to +15 C? How about the other 98% comprised of nitrogen and oxygen? The NOAA satellites, from which UAH and RSS make their data sets, measure microwave radiation from oxygen. That means the oxygen is representative of the actual atmospheric temperature. How did it get to that temperature? Nitrogen and oxygen can’t absorb surface radiation, so where did they get their heat? Surely not from the 2% of GHG gases.”
This is well understood based on the measured spectra of the gases. Tyndall was able to make the measurements 150 years ago, which show that the N2 and O2 do not absorb any of the domininant black body radiation which is in the IR band, headed upward from the surface, and that trace gases such as WV, CO2, CH4 etc. because of their absorption spectra are responsible for absorbing and remitting much of the upward IR and sending it back to the surface of the earth. The spectra have been measured more accurately since then, and the picture has been refined, and the calculations computerized and made more accurate. The radiation absorbed by the trace gases where the atmosphere is dense, is thermalized fairly promptly as a result of intermolecular collisions. Any one with a reasonable scientific education could even find and read these explanations on the internet in college course notes for free.
The microwave radiation you are speaking of represents a tiny fraction of the thermal energy radiated based on the standard Plank equation for the radiation spectrum. The bulk of it is in the IR band, and satellite measurements of upward IR radiation show reduction in radiation in the absorption bands of CO2 and H2O.
http://upload.wikimedia.org/wikipedia/commons/thumb/7/7c/Atmospheric_Transmission.png/350px-Atmospheric_Transmission.png
The fact that you persist in your denials of these accepted physical theories shows how the human mind can be deluded by a desire to believe what it wants and discard solid scientific theories.
“On top of that, anthropogenic CO2 accounts for about 3% of all atmospheric CO2 which accounts for 0.03 % of atmospheric gases. How does such a piddly amount of CO2 create a positive feedback with enough magnitude to cause a thermal runaway?”
First of all the correct way to look at this is that since the industrial age began, human emissions of CO2 are double the amount of CO2 increase retained in the atmosphere, which is about a 25% of what exists in the atmosphere today. Nature absorbs more CO2 than it emits.
So your number of 3%, whatever that is based on is irrelevant.
Secondly, I haven’t seen any papers on thermal runaway due to doubling of the CO2 concentration. I have seen a finite figure of 3C increase in global average temperature, with larger increases at the poles and less in the tropics. The increase without feedback due to CO2 alone would be 1C.
“WV is part of a replenishable cycle. Even though it only makes up 1% of atmospheric gases on average, it is being constantly replenished by the oceans and the land surface. As such, WV is part of a large convection cycle. When you compare that replenishment to the replenishment of CO2, their is no comparison. Based on a 380 ppmv density for CO2 and a 0.6% increase in ACO2 per year, Roy Spencer calculated that anthropogenic CO2 increases at 1 molecule of CO2 to 100,000 molecules of air, every 5 years.
The argument that such a tiny amount of ACO2 can increase atmospheric temperature through positive feedback, just doesn’t hold any water vapour.”
This last bit is all handwaving and irrelevant numbers. There is no scientific argument here, just gesturing.
“The microwave radiation you are speaking of represents a tiny fraction of the thermal energy radiated based on the standard Plank equation for the radiation spectrum. The bulk of it is in the IR band, and satellite measurements of upward IR radiation show reduction in radiation in the absorption bands of CO2 and H2O.
http://upload.wikimedia.org/wikipedia/commons/thumb/7/7c/Atmospheric_Transmission.png/350px-Atmospheric_Transmission.png”
A very important diagram that explains so much, and essential for anyone trying to understand AGW theory, or argue against it.
I found this article by Hartwig Volz, which addresses water in its liquid form rather than just water vapor, interesting.
http://www.klimanotizen.de/2006.06.17_Sea_Water_Emissivity_Volz.pdf
That 33 C greenhouse effect assumes the earth is a black body. Those greenhouse gases don’t increase the flux by 390 watts/240 watts = a factor of 1.625, but more like
0.95 (390)/240 = 1.54375
Also, most of that reduction in flux from 342 watts to 240 watts is due to water vapor in the form of clouds. What water vapor taketh away in the form of albedo, it giveth back in greenhouse warming.
There can be significant positive feedbacks: decreases in ice at the end of ice ages, or additional ice in deepening ice ages, in rougher seas during advancing ice ages, or calmer seas at the ends of ice ages. Since we’re close to the no ice age side of climate, most of those positive feedbacks would only work in the expansion of a new ice age. There’s very little room for positive feedback in further warming.
Look there goes another possum!
Eric and SJT would rather waltz us down a garden path away from M. Hammer’s critique in a hunt for non sequiturs.
M. Hammer said:
“So how is it possible that the summer/winter temperature variation at Mackay is so much less than the change in solar input would suggest? The reason is that water vapour generates lots of feedback effects and many of them are very strongly negative (feedback that reduces the impact of changes in energy input). Evaporating water takes a very large amount of energy. As more water evaporates in the summer it absorbs the necessary energy from the environment reducing the temperature rise. Greater humidity also leads to more condensation and thus clouds which reflect a larger fraction of the incoming solar energy back out to space and away from Earth’s surface. It also takes energy to lift the water vapour several kilometres into the atmosphere against earth’s gravity to the altitude where it condenses to form clouds and falls back as rain (after all that is where the energy for hydroelectricity comes from). The temperature data clearly shows that these negative feedback mechanisms strongly dominate over the slight increase in retained energy with increasing water vapour concentration.
The IPCC temperature rise claims are based on an assumption of strong net positive feedback in our climate system yet natural systems virtually all exhibit strong negative feedback around an equilibrium point. Negative feedback is the opposite of positive feedback. It acts to oppose any disturbance acting on a system and seeks to maintain the current equilibrium. In short it is a stabilising factor whereas positive feedback is a destabilising factor. Long term stability of any natural system almost guarantees that there is strong negative or stabilising feedback in operation. The climate, while showing periodic variations, has been stable enough for life to form and flourish for millions of years despite significant changes in forcing over the millennia and this makes it virtually certain that strong negative feedback is in operation. The fact that IPCC claim a large degree of positive feedback in our climate system suggests there may be a flaw in their theory.
If, as I believe, the net feedback from water vapour is negative rather than positive then the actual temperature rise by 2070 even with a doubling of carbon dioxide is likely to be less than the half a degree predicted in the absence of feedback, probably no more than 0.2 to 0.3 degrees.”
That’s the topic, Eric, STJ, et al. Please address the issue directly, if you can.
Comment from: Jan Pompe April 3rd, 2009 at 9:12 am
“Eric “The first law of thermodynamics is not violate by the WV feedback mechanism”
Nature who taught us the laws of thermodynamics does not violate them, so whatever feedback there is [it’s negative] does not violate the laws but for your amateurish explanations to be true she would have to make an exception.”
There is no logic whatever in your statement. Whether the actual feedback is positive or negative, has no bearing, on whether the proposed mechanism violates the first law of thermodynamics. The proposed mechanism is a combination of the enhanced evaporation at higher temperatures, and the greenhouse effect which maintains those higher temperatures by suppressing the escape of energy originating from the sun. Since the sun is a continuous source of energy external to the system, there is no reason for the first law of thermodynamics to be violated.
“Eric
“The source of energy to drive the additional feedback is solar radiation.”
NO Eric you can’t count it twice it’s the original signal that you claim the the positive feedback amplifies it can’t also be the auxiliary power reservoir. Restrained power is not extra power thinking that it is, is a serious mistake.”
There is no extra power. Water vapor is constantly produced and condensing. What we are talking about is the average density of water vapor changing over a long period of time. The latent heat stored in a 14% change in the average water vapor density in the atmosphere is a miniscule fraction of the solar radiation arriving at the earth over the next 100 years. Nothing is being counted twice.
http://en.wikipedia.org/wiki/Water_vapor
” The annual mean global concentration of water vapor would yield about 25 mm of liquid water over the entire surface of the Earth if it were to instantly condense.”
An increase of 14% would result in 3.5mm of liquid water. How many hours of solar radiation over 100 year period would it take to evaporate that much? Are you arguing that the solar radiation to do that is impossible to obtain and therefore the energy source is not there?
A quick estimate says that it would take 9.15 hours of solar radiation over 100 year period to do that.
It is pretty clear that you are talking nonsense.
Comment from: wes george April 3rd, 2009 at 11:05 am
Look there goes another possum!
Eric and SJT would rather waltz us down a garden path away from M. Hammer’s critique in a hunt for non sequiturs.
M. Hammer said:
“…..”
That’s the topic, Eric, STJ, et al. Please address the issue directly, if you can.”
Michael’s argument is a qualitative argument about a phenomenon that requires painstaking analysis and accurate computation. On its face, it can’t prove such the model calculations are incorrect. There is no accuracy whatever inherent in the post.
Secondly, of all, the temperature data, as I pointed out in my above reference show that the recent increase in average temperatures came predominantly from and increase in nighttime temperatures, which are twice the increase in daytime temperatures. This shows that Michaels observation that heat is predominantly retained by the Greenhouse effect at night, is consistent with the way the way temperature is observed to increase.
There is also the usual confusion between positive feedback and runaway. I alluded to the feedback equation above.
O=g*I + f*O.
The solution is O=g*I/(1-f)
As long as f =1 we have runaway. Michael argues that we have a stable system, therefore there f<0, i.e. we have negative feedback. That is clearly wrong. The requirement for a stable system is f<1.
Thank you for giving me the excuse to repeat the arguments I have already made, and keeping the discussion on track.
Plese excuse my typo in the above post, which may be confusing. I should have written:
If f =>1 we have runaway.
Michael argues that we have a stable system, therefore it is necessary that f<0, i.e. we have negative feedback. That is clearly wrong. The requirement for a stable system is f<1, so positive feedback does not make the system unstable and run away.
Positive feedback can be consistent with the oscillations we have seen of the earth’s climate due to orbital and axis precession, i.e Milankovich cycles, in the Vostok ice core data. This would include albedo, water vapor and CO2 related feedback.
“The IPCC temperature rise claims are based on an assumption of strong net positive feedback in our climate system yet natural systems virtually all exhibit strong negative feedback around an equilibrium point.”
No “assumption”. It’s all based on research.
Comment from: Louis Hissink April 3rd, 2009 at 8:28 am
“Wes,
In addition we have one rule in science – if you can’t explain what work you do to your grandmother, then you don’t really understand it yourself.
The ability to describe a scientific idea in layterms means you know what you are dealing with, and Mike Hammer as done that.”
I think you have a basic error in logic here if you are claiming that your first statement implies the second statement.
It is possible for your first statement to be true, but at the same time it doesn’t rule out the possibility that a scientist who doesn’t understand what he/she is doing is able to explain the work that they are doing to a laymen. There is no logical inconsistency in between this case and your first statement.
If as you say, being able to explain something may be a necessary condition to show that you are doing good science, but that does not imply that it is sufficient to show you are doing good science. The history of science is full of wrong plausible explanations that were accepted by the public.
AGW denial, and specifically Michael’s blogpost is full of errors that seem plausible to laymen, like yourself. Let’s face it, Michael isn’t even doing climate science as such. He has a masters degree in engineering and has worked on spectroscopy, so he doesn’t qualify as a climate scientist. He is just a John Q blogger like me.
A very good article that explains what we are in fact seeing, as opposed to what the warmenists models say we should be seeing. Just loved this classi understatement:
“suggests there may be a flaw in their theory”
Eric Adler:
“It is possible for your first statement to be true, but at the same time it doesn’t rule out the possibility that a scientist who doesn’t understand what he/she is doing is able to explain the work that they are doing to a laymen.”
If one does not understand what one is doing explicitly means you cannot explain it to some one else either – and you are really picking nits here on the basic of semantics.
I’ve got a couple of science degrees so the rest of your post needs to be rewritten in terms of this newly found knowledge.
Sigh.
Poor Eric. He is perfectly fit to engage in quantitative discourse in plain English with other commenters on any topic but, of course, M. Hammer’s thesis.
The audience here can clearly see that Eric is incapable of directly addressing M. Hammer’s blog post without resorting to ad homs, logical errors, non sequitur and obscurantism.
In dialectics, this is often euphemistically referred to as a deafening silence. But for most lay members of the audience here it just plain pathetic. We feel an uncomfortable sense of, well, embarrassment for Eric and wish we could help.
Eric Adler:
Eric, please go back to RC, or your native planet, where you can have your feathers stroked each day by the voices of mediocrity and “consensus-speak.” You are clearly not interested in learning anything, but you are just a bot of some sort. Probably an NGObot. There are thousands of them, believe me.
SJT says that the IPCC’s claims are not based upon “assumptions” just “research.”
Some of the synonyms most commonly used for “assumption” are premise, hypothesis, deduction, inference, summary, conjecture and presumption.
Indeed, If I may be so presumptuous, I believe that if would be fair to speculate that SJT doesn’t know his ass umption from his elbow.
What’s this Cohers – we’re now using global generalisations to attack a highly specific well conducted bit of regional research. And clouds when it’s cloud free?? – you get the limp lettuce leaf award. Called circulation patterns mate. Hence the other papers. A threshold test for you.
luke,
“just a janitor”
Nah, you couldn’t be, I know a few.
Roy Spencer has just added a rave about greenhouse.
http://www.drroyspencer.com/2009/04/in-defense-of-the-greenhouse-effect/
That should read “…a highly specific well conducted bit of ASSUMPTIONLESS regional research.”
Limp lettuce leaf award? Luke, that’s pretty lame. There’s no poetry, alliteration, nothing. It’s just weak. Lift your game, mate, you limp-wristed janitor from the high church of Climinanity.
We’re still waiting for Eric to come back for his 2nd place prize in today’s debate, which I conjecture is over.
Yeah, alright luke, I don’t mind spending a bit of time on Philipona who seems to have a new report coming out every week; in a 2007 study by P and Ruckstuhl predicts “reduced temperature rise in the new century that is just due to greenhouse” because of the end of solar brightening due to aerosol stabilisation [Geophysical Research Abstracts, Vol 9, 2007]; in this study P maintains the “strong water vapor feedback line”; 2 things about that; firstly, as is plain, SH is declining at mid to high altitudes while increasing slightly near surface;
http://www.climate4you.com/ClimateAndClouds.htm#Clouds%20and%20atmospheric%20water%20vapour
The situation with clouds as shown in the above link is more complex but generally consistent with temperature; notably the link observes;
“The global cloud data are of course dominated by the huge surface areas near the Equator, and on a smaller scale the regional and local effect could well deviate from the average global cooling effect ”
Philipona does regional studies; you complain when I point out that global parameteres differ from P’s regional findings [and this is assuming his findings are correct] but you don’t complain if global extrapolations are made from P’s regionalised study.
Secondly, P assumes a +ve water feedback from initial CO2 forcing; this is not explained; this contradicts it;
http://www.john-daly.com/artifact.htm
If the back-radiation is not warming then a +ve feedback is a contradiction in terms; in addition the ‘feedback’ from water can’t be coming from higher altitudes where water is declining; but if it is coming from near-surface why isn’t the evapotranspirational process of getting the slight increase of water into the atmosphere causing cooling as part of the transfer?
Luke; IMO our cohers is a lost cause, can’t do the math or the practice by himself.
Jae too is becoming very disappointing “Eric, please go back to RC, or your native planet” when Eric was doing a great job steering this ship through troubled waters. All that stuff where f = 1 whatever is spot on in feedback loops chaps.
In reflection I recalled that time when this apprentice nearly got sent home after being suspected of helping the boys build big guitar amps for their Fender loving band mates. We were location in the service workshop for darkened process labs during their run time. When does a high power push pull tube amp class AB or B give the game away? When the feedback is wired wrong and it squeals!
http://ozvalveamps.elands.com/playmaster.htm
http://en.wikipedia.org/wiki/Electronic_amplifier#Class_B_and_AB
The problem with good people like MH coming out first in a forum such as this, its too easy for the odd balls like me to say he hasn’t been round the ropes enough yet. Anyone who has learnt the fear of dealing with say superheated steam on a daily basis can’t forgive basic slips on latent heat etc.
Yesterday I poured a 3/4 full kettle of hot water into a used litter tray outside because the day was forecast “overcast with drizzle”. No sun no sterilization I thought but I became curious when the water started to disappear. Also; we had a guy rushing to clear trees from under power lines as the drizzle became apparent, a mild day, by our current expectations.
It seems any water I left in the kitty tray has evaporated overnight but it only reached 19C again this morning. We can be sure it was as much to do with the air flow as the air temperature. Also this extraordinary dryness has cost the trees and the garden. I paid our man on half his normal rates yesterday one thousand dollars to take what he could in the time he allowed for the larger and sicker specimens.
Solar energy has many forms.
Gavin: WOW “Luke; IMO our cohers is a lost cause, can’t do the math or the practice by himself.
Jae too is becoming very disappointing “Eric, please go back to RC, or your native planet” when Eric was doing a great job steering this ship through troubled waters. All that stuff where f = 1 whatever is spot on in feedback loops chaps.”
All this from someone who mistakes his finger for a voltage probe.
Wes,
Comment from: wes george April 3rd, 2009 at 12:51 pm
Sigh.
Poor Eric. He is perfectly fit to engage in quantitative discourse in plain English with other commenters on any topic but, of course, M. Hammer’s thesis.
The audience here can clearly see that Eric is incapable of directly addressing M. Hammer’s blog post without resorting to ad homs, logical errors, non sequitur and obscurantism.
In dialectics, this is often euphemistically referred to as a deafening silence. But for most lay members of the audience here it just plain pathetic. We feel an uncomfortable sense of, well, embarrassment for Eric and wish we could help.”
Wes I am puzzled. I accepted your invitation to reply to a few paragraphs of Mr Hammers post that you considered important, because you missed the points I made previously.
I pointed out that the mode of temperature increase that predominated recent temperature increases was nighttime temperature, which was consistent with what would be expected from a mechanism like the greenhouse effect, which acted to reduce the loss of heat to outer space, in agreement with what Hammer would predict. He seemed not to realize that in his post.
The second point I made was that contrary to Hammers statement, positive feedback was consistent with at stable climate system that we have observed. The feedback coefficient f can be positive so long as it is less than 1.
If there is something incorrect about the points that I have made, please explain.
The fact that you have to resort to trash talk makes it seem as if you have no substantive reply, and simply resort to empty disparagement of what I say. I believe that calling my posts obscurantism, could be a way of avoiding the risk of showing that you don’t understand what I am talking about if you tried to answer the points that I made.
You also seem to have a strategy of declaring victory for your “side” instead of engaging in debate. I guess it is easier that way.
Jae,
You never answered my question about whether you thought the proposed mechanism for positive feedback due to water vapor violated the first law of thermodynamics. What do you think about that?
Apparently you don’t like any back talk either.
Comment from: janama April 3rd, 2009 at 1:46 pm
“Roy Spencer has just added a rave about greenhouse.
http://www.drroyspencer.com/2009/04/in-defense-of-the-greenhouse-effect/”
This is a very good explanation of why G&T and others who rave about how the GHE violates laws of physics are wrong.
Of course there are some who are disappointed in Roy. They will say he is just doing that to stay in the good graces of the scientific community so he can get his paper published in a real scientific journal instead of E & E, or the obscure journal where G & T published.
But be consoled. Maybe it is a good strategy, so that Roy can strike a real blow for the sceptic “cause” by getting pubished in a respectable journal.
Eric you would tell a person with 30 + years professional experience in Feedback and Control mechanisms including adpative parameter control that he is talking nonsense?
You really are a great example of of an empty vessel making lots of noise like Gavin was when he took on Jeffrey Glasson an expert in using using jet exhaust as feedback for missile guidance system. It’s quite a deal more tricky than IPCC climate nonsense.
“The proposed mechanism is a combination of the enhanced evaporation at higher temperatures,”
I have here a brief explanation why positive feedback is not possible and negative feedback is questionable.
The link
http://www.esnips.com/doc/a1735013-5fd6-440e-acf2-8aa0ea66aa99/PassiveFeedback
Eric Adler “This is a very good explanation of why G&T and others who rave about how the GHE violates laws of physics are wrong”.
The problem is that G&T are physicists while Roy has a degree in meteorology. As much as I respect Roy and the work he has done with satellite data sets, expecting him to be an expert on physics or thermodynamics is akin to expecting a physician to be an expert on nutrition. Physicians take a six month course in nutrition, and call Linus Pauling a quack for suggesting megadoses of vitamins. They fail to acknowledge that Pauling was a world-class expert in chemistry and that the body is essentially a chemical factory.
I find it tiresome to watch people clinging to this model of the atmosphere as a greenhouse. SJT keeps nagging about it, pointing out that it’s only a model, but failing to understand that it’s an inadequate model. The good side here is that SJT has found a new friend in Roy Spencer. Hopefully Roy’s work on the atmosphere with satellites and his claim that the models are wrong will rub off on SJT and Eric Adler.
“Eric you would tell a person with 30 + years professional experience in Feedback and Control mechanisms including adpative parameter control that he is talking nonsense?”
If the shoe fits. A microphone can only feedback through the PA if the power is on. Turn of the power, no feedback.
““Roy Spencer has just added a rave about greenhouse.
http://www.drroyspencer.com/2009/04/in-defense-of-the-greenhouse-effect/”
This is a very good explanation of why G&T and others who rave about how the GHE violates laws of physics are wrong. ”
😉 pwned. G&T can now be consigned to the dustbin of history.
“Eric you would tell a person with 30 + years professional experience in Feedback and Control mechanisms including adpative parameter control that he is talking nonsense?
You really are a great example of of an empty vessel making lots of noise like Gavin was when he took on Jeffrey Glasson an expert in using using jet exhaust as feedback for missile guidance system. It’s quite a deal more tricky than IPCC climate nonsense.
“The proposed mechanism is a combination of the enhanced evaporation at higher temperatures,”
I have here a brief explanation why positive feedback is not possible and negative feedback is questionable.”
In your derivation, you are making the assumption that there is no external power source and you have a passive system.
We have gone over this before, but you apparently overlooked it or forgot.
The earth has an external power source – the sun. As I pointed out before, it would take evaporaton of only an additional 3.5mm water to provide the positive feedback found by running the Climate Models. This would consume 9.15 hours of sunlight. There is plenty of solar energy to provide the positive feedback, over a 100 year, or 800,000 hour period to evaporate enough WV to maintain the positive feedback assumed in the climate models. It would take about 1/100,000 of the energy provided to the earth by the sun during that time period.
Explain what is wrong with that argument.
I am going to sleep now. I will check back later.
Well our little will is at last learning something.
“If the shoe fits. A microphone can only feedback through the PA if the power is on. Turn of the power, no feedback.”
Well done!!
“Comment from: Gordon Robertson April 3rd, 2009 at 3:27 pm
Eric Adler “This is a very good explanation of why G&T and others who rave about how the GHE violates laws of physics are wrong”.
The problem is that G&T are physicists while Roy has a degree in meteorology. As much as I respect Roy and the work he has done with satellite data sets, expecting him to be an expert on physics or thermodynamics is akin to expecting a physician to be an expert on nutrition. Physicians take a six month course in nutrition, and call Linus Pauling a quack for suggesting megadoses of vitamins. They fail to acknowledge that Pauling was a world-class expert in chemistry and that the body is essentially a chemical factory.
I find it tiresome to watch people clinging to this model of the atmosphere as a greenhouse. SJT keeps nagging about it, pointing out that it’s only a model, but failing to understand that it’s an inadequate model. The good side here is that SJT has found a new friend in Roy Spencer. Hopefully Roy’s work on the atmosphere with satellites and his claim that the models are wrong will rub off on SJT and Eric Adler.”
Gordon, by this post, you show how illogical your thinking is and how ignorant you are.
G & T are physicists who have done no research on climatology or meteorology. They are out of their field much more than Roy is when dealing with the greenhouse effect. Meteorology is a branch of physics.
If you read G & T’s paper, you will see it is mostly a political rant. They have gone off the deep end. There is very little technical material in it. Maybe you can’t tell the difference.
Eric “Explain what is wrong with that argument.”
Impossible. It’s absolutely right!
Eric Adler “Let’s face it, Michael isn’t even doing climate science as such. He has a masters degree in engineering and has worked on spectroscopy, so he doesn’t qualify as a climate scientist”.
Oh…but Gavin Schmidt, with a degree in math does qualify. or Michael Mann with a degree in geology, or James Hansen with a degree in astrophysics. If we can agree that only people with legitimate degrees in climate science (meteorology, atmospheric physics) like Spencer, Christy, Lindzen, Trenberth et al, can be taken seriously, that would eliminate about 7/8ths of the reviewers on the IPCC. It would also eliminate most of the reviewers on the Journal of Climate.
Sorry…I can’t accept computer modeling as a legitimate science. It’s like string theory is to physics, a damned nuisance.
Eric Adler re feedback “Explain what is wrong with that argument”.
You don’t understand the first thing about positive feedback and it’s requirements. You don’t understand what is meant by a passive system as opposed to an active system. Don’t worry, neither do any of the other AGW crowd.
“The problem is that G&T are physicists”
I think many physicists would dispute that.
Eyrie “We’ve actually seen evidence of the formation of other solar systems from dust clouds , Gordon”.
I’ll try to answer the rest of your post tomorrow, but for now, what did you see them through? Before Hubble, the biggest optical telescope on Earth could only see Jupiter at the same size as a large coin. Even with Hubble, the size and resolution has not increased to the point where anyone can see solar systems forming.
That leaves radiotelescopes, which do the majority of viewing in the universe. They can’t see anything visually, they just gather radio-waves emitted by molecules and atoms in space. There’s a heck of a lot implied in the Universe but most of it is comjecture. We don’t even know what’s happening on Mars or venus, or the Moon, never mind several zillion miles away.
But…ah, yes…we have evidence. We have evidence of the Big Bang too, if anyone is naive enough to believe it. Sorry…but I can’t get into turning Doppler shifts in the spectra of stars and a +4K background temperature in the Universe into a Big Bang.
Inscrutable at best. You don’t think the sun is a source of power?
Poor Eric, he’s giving everyone a good fisking. Even Louis’s old grandmother gets a good lashing. Everyone but Michael Hammer.
Now Eric declares his meaningless rambles in the garden represent more than a possum hunt.
An short extract of Eric’s “rebuttal”:
“Clearly if O is quantity of energy , since cannot be created or destroyed, the feedback mechanism must have a source of energy to increase the output by a factor f*O._In the case of a microphone and amplifier system, clearly the amplifier is plugged into an electrical energy source and a portion of the sound from the speakers will come back into the microphone and be amplified again.In the case of the earth/atmosphere system, and the temperature feedback mechanism, the source of the energy is the sun. Energy is constantly arriving from the sun, and leaving. The energy to increase the earth’s temperature obtained by a feedback mechanism which reduces the rate at which energy from the sun exits. It cannot therefore be argued that conservation of energy prevents positive feedback for temperature increases.”
Pluuuze. This sounds like an audition for Lucky’s scene in Waiting from Godot:
http://video.google.com/videosearch?client=safari&rls=en&q=Waiting+for+Godot&oe=UTF-8&um=1&ie=UTF-8&ei=yKnVScH_FdKfkQWCy93HBA&sa=X&oi=video_result_group&resnum=4&ct=title#
Honestly, if Eric had a reasonable counter argument then he would have gone point by point from the top of Hammer’s thesis to the bottom and left us all nodding our heads long ago.
But we’re at comment Number 140 and Eric’s credibility has decayed to the level a SJT or a Gavin, just another mindless evangelist who believes, as Gavin so brilliantly put it:
“In general; there is no point in anyone reading what experts have written if they are not going to “go with the flow.”
Qua, qua, qua
Sorry here’s Lucky as performed by Eric Alder link again.
Little will spews: “Inscrutable at best. You don’t think the sun is a source of power?”
If you were either a physicist or better still an engineer you would be having these problems and it would not be inscrutable to you.
The sun is a source of power so is the microphone that is plugged into an amplifier it’s input depending on the type might range from a few micro-watts to maybe (being very generous) a milliwatt for that signal to be able to drive, say, a 5 watt speaker we need to be able to amplify that small 1 mW 5000 times and to able to do this the amplifier needs to draw on a power supply to provide the difference. The system being usually far from ideal will typically operate ate 50% efficiency (a maximum efficiency for ideal for a class B is about 70%) so it will be drawing 10 watt from the wall plug.
NOTE there are 2 power sources one the signal from the microphone and the other from the the power station.
With the earth climate system being a purely dissipative system has only one power source the sun and that is the input there is no other source for it to draw on for the signal to be amplified.
Eric’s formula for feedback is incorrect;
O=g*I + f*O
requires a constraint; so;
O=g*I+logf*O
A further constraint is provided by:
ED=SU[1-TA]
Where ED is downward atmospheric radiation, SU is upwelling radiation and TA flux transmittance, effectively temperature; this holds true at any point vertically and horizontally with every point being a LTE, Local Thermodynamic Equilibrium; with each LTE being different in energy due to ED and SU, thermal gradients exist between them creating lapse rates and weather through convection. While Eric is right in saying energy is neither created or destroyed, it will be utilised through the work of transferring energy from warm to cold LTEs; this is the gist of the Kleidon MEP reference I provided earlier; what is the significance for the greenhouse? Energy is used transferring itself from warmer to colder areas where the radiation is relatively unfettered in leaving.
What is the role of water in this? SH over sea areas correlates with solar radiation and latitude with 22 gms/kg air in the tropics to 4gms/kg in the polar regions. This determines the adiabatic temperature lapse rate in the atmosphere. In the wettest regions it is 4C/km and the cold, dry regions 10C/km. The heat transfer upwards from the warm surface is 2.5 times more than the cold surface. Water cools the warm region, warms the cold region; cools at day and in summer, warms at night and in winter.
Eric’s feedback is non-existent.
“With the earth climate system being a purely dissipative system has only one power source the sun and that is the input there is no other source for it to draw on for the signal to be amplified.”
But what is powering the microphone? It is just a transducer for a signal. The CO2 forcing is also a ‘signal’, that is being “amplified”, via positive feedback mechanisms.
Gordon “The problem is that G&T are physicists while Roy has a degree in meteorology.”
It’s not just Roy. There seems to be a trend for the more scientifically literate of the sceptics to steer people away from this silly deadend of denying straightforward, measured radiative physics. Here’s Richard Lindzen, being very clear:
While the atmosphere is relatively transparent to shortwave radiation (sunlight) it is nearly opaque to infrared radiation, owing to the presence of certain trace gases and of clouds. Much of the infrared radiation passing upward from the Earth’s surface is absorbed and reradiated, both upward and downward. Because the surface therefore receives not just solar radiation but also infrared radiation from the atmosphere and clouds, it is much warmer than it would be in the absence of the atmosphere.
“While the atmosphere is relatively transparent to shortwave radiation (sunlight) it is nearly opaque to infrared radiation, owing to the presence of certain trace gases and of clouds. Much of the infrared radiation passing upward from the Earth’s surface is absorbed and reradiated, both upward and downward. Because the surface therefore receives not just solar radiation but also infrared radiation from the atmosphere and clouds, it is much warmer than it would be in the absence of the atmosphere.”
It is clear, and it is also consistent, and it kills G&T stone dead. The only argument is over the extent of warming CO2 is going to cause.
So will Cohers, Wessy Wonk, and Gordon support Lindzen’s comments – or is he wrong? Do you support his comments – yes or no will do….
I’m always amused by the assumption of superiority by the AGW supporters; dictating terms of surrender; “yes or no will do”; ah, the clarity. But seriously folks has noone got anything to say about eric’s formula and its necessary adjustment; as for Roy and Richard, p3 of this is instructive;
http://eaps.mit.edu/faculty/lindzen/153_Regulation.pdf
I don’t mind saying some things give me pause; the implacable, incessant Philipona [does this man ever stop to sleep or is he a paper producing perpetuum machine?] but the list of chicanery and dud ‘science’ supporting AGW is growing; as well, the issue of atmospheric pressure contributing to temperature has not been discussed at all despite it being raised by paminator yesterday at 12.32pm on this thread; so in the interests of transparency I state I think there is some heating contribution by the GHGs particularly water; I think G&T have made a valuable contribution to the discussion and I think the enhanced greenhouse is a load of bunk.
Coho, Eric’s formula is correct. Your “correction” makes no difference, in an incoherent sort of way. f is just the fraction of output that is fed back. It’s a number; expressing it as the logarithm of something makes no difference, and does not impose a constraint.
The next part is full of malapropisms. A point can’t be “a LTE”; a region of matter, usually gas, is in a state of LTE. Thermal gradient doesn’t create a lapse rate – a lapse rate is a thermal gradient. “LTE”‘s don’t have a difference in energy; two different regions in LTE might. etc
Luke, you’re on the wrong blog. The Lindzen debate is over at Wattsup.
This is the Michael Hammer WV debate and we’re still waiting for anyone to make a single interesting rebuttal to Michael Hammer’s premise after 175 comments.
Look, there goes a possum! Yes, Luke we know you’d like to change the topic.
Wille E. Luke’s rhetorical style:
http://www.youtube.com/watch?v=hz65AOjabtM&feature=related
Isn’t funny how Luke is just like coyote, no matter how many times you kill him, he just keeps coming back for more.
A general comment following from Nick Stoke’s post of 7:02pm.
If an increase in CO2 produces a slight warming per the reasoning by Richard Lindzen, then it it clear, based on gas behaviour, that O2, N2 and traces gases (CO2 included) should be well mixed, and that an additional phase of water , either as a gas and thus absence of clouds, or as suspended liquid , thus a physical two phase system, adds complexity. We might then consider 3 types of atmosphere for this particular problem
1. Air with negligible water vapour
2. Air with high humidity but still single phase (no clouds)
3. Air with clouds and thus a 2 phase system.
Common to 1,2 and 3 is CO2 and it is the variable while the rest are assumed constants. So we double CO2 and, according to theory, temperature should increase by 1K, everything else being equal.
The earth’s thermal state is a dynamic system which fluctuates around a base level, and it is thought from an increase in CO2 in particular, that this base, or background, level temperature will rise as a consequence. So over time it would be useful to examine a typical desert weather monitoring station, say , the Giles one in Central Australia. This site is chosen because of its physical remoteness.
No Temperature increase in central-east WA
Giles Meteorological Office is located on the far east of Western Australia on about the same latitude as Uluru. It is one of the BOM’s most famed stations, largely due to it’s isolation. It was initially built to provide data for the British atomic weapon tests and later the rocket trials from Woomera. Considering that there are no major weather stations around the area that have a good back history of data, we have decided to analyse this station by itself.
Our analysis will include maximum and minimum temperatures as well as temperature changes throughout the day over the years. Data goes back to 1957 for maximum and minimum temperatures, whilst you have to go back to 1978 for time related temperatures with the exception of temperatures at Midnight which only go back a fraction over 10 years.
Giles maximum temperatures over time are shown here with their minimum temperatures shown here. There was no significant increase or decrease in any of these over time (max: t = 0.81, p = 0.42, min: t = 1.37, p = 0.18).
It is understandable therefore that there should be no significant differences in temperature for any of the time related temperatures. And there wasn’t. Midnight showed no significant increase or decrease ( t = -0.02, p = 0.98) as well as for 3am (t = -1.18, p = 0.25), 6am (t = -0.54, p = 0.59), 9am (t = 1.36, p = 0.19), noon (t = -0.21, p = 0.83), 3pm (t = -0.64, p = 0.53), 6pm (t = -1.41, p = 0.17) and 9pm (t = -1.74, p = 0.09).
Interestingly most times showed decreases in temperature however none were significant at the 5% level. The large reason for this was in the years 2000-2002 which saw maximum temperatures at up to 1.5 degrees below the average and minimum temperatures at 1 degree below the average. Temperatures at 6pm and 9pm showed almost 2 degrees below the average during these years.
Maximum and minimum temperatures have been above average in the last 5 years, however this has proven insignificant.
In conclusion there is no evidence to prove that temperatures are increasing or decreasing in central-eastern Western Australia.
Labels: weatheranalysis
Pasted from
If the Giles weather station is typical of a “desert environment” and thus free of anthropgenic influences, then an increase in CO2 should be noticed in the temperature measurements.
That this is not observed means one thing – our understanding of the problem is incomplete.
Thank you Nick; you are much kinder in your ‘assistance’ than eli or those Deltoid bullies; but just as problematic; ‘f’ from the formula is CO2; it is subject to an asymtopic logarithmic decline; plugging that fact into the equation;
O=g*I + f*O
O-f*O =gI
O(1-f)=gxI
O=gxI/1-f
As f approaches zero O=g*I
Which is to say no feedback;
Your other complaints are faintly pedantic; I used gradient to distinguish a vertical lapse rate/gradient from a horizontal lapse rate/gradient; my use of ‘point’ was inexact; but I disagree with you that all LTEs are the same; an LTE is the distance or layer of air that is not thicker than the mean free path of an interacting photon; that is some metres; 2 things; that path is defined or set by local temperature, the key word being local; and it means there is no discontinuity between the surface and the immediate air. Since a LTE is local and determined by local temperature, all LTEs must be different.
Now if you can put that lot together with Miskolczi’s fixed optical depth I would be grateful.
Comment from: Gordon Robertson April 3rd, 2009 at 3:53 pm
Eric Adler “Let’s face it, Michael isn’t even doing climate science as such. He has a masters degree in engineering and has worked on spectroscopy, so he doesn’t qualify as a climate scientist”.
Oh…but Gavin Schmidt, with a degree in math does qualify. or Michael Mann with a degree in geology, or James Hansen with a degree in astrophysics. If we can agree that only people with legitimate degrees in climate science (meteorology, atmospheric physics) like Spencer, Christy, Lindzen, Trenberth et al, can be taken seriously, that would eliminate about 7/8ths of the reviewers on the IPCC. It would also eliminate most of the reviewers on the Journal of Climate.
Sorry…I can’t accept computer modeling as a legitimate science. It’s like string theory is to physics, a damned nuisance.”
You made an argument about whose theory was correct on the basis of what degree they held.
I didn’t agree with that argument. I didn’t make an argument about whose theory was better on the basis of what degree they hold, but rather on the basis of the work that they do.
The poor little girls ducked it. ooooooo suddenly gone all bashful have we dudes.
You pussies. We’ll take the smoke and mirrors as “oh no we’re caught in the open”
“we’re not mental or anything” and “WE ARE NOT WORTHY”
Reminds me of
Comment from: Jan Pompe April 3rd, 2009 at 5:18 pm
“Little will spews: “Inscrutable at best. You don’t think the sun is a source of power?”
If you were either a physicist or better still an engineer you would be having these problems and it would not be inscrutable to you.
The sun is a source of power so is the microphone that is plugged into an amplifier it’s input depending on the type might range from a few micro-watts to maybe (being very generous) a milliwatt for that signal to be able to drive, say, a 5 watt speaker we need to be able to amplify that small 1 mW 5000 times and to able to do this the amplifier needs to draw on a power supply to provide the difference. The system being usually far from ideal will typically operate ate 50% efficiency (a maximum efficiency for ideal for a class B is about 70%) so it will be drawing 10 watt from the wall plug.
NOTE there are 2 power sources one the signal from the microphone and the other from the the power station.
With the earth climate system being a purely dissipative system has only one power source the sun and that is the input there is no other source for it to draw on for the signal to be amplified.”
By trying to be cleverer than your level of competence allows, you have allowed your mind to be trapped by a false analogy. You are claiming that the variable which is the output variable O, in my equation is a kind of energy flux in Watts, and the feedback of temperature on itself through the water vapor feedback represents a the analog of a passive network such as you have derived your marvelous theorem valid for electronics.
This is in fact not the case. Temperature is a totally different variable from energy flux. It is like voltage. You can amplify voltage in a passive network ie. a transformer.
If you are looking at the energy flux as a variable, the sun’s flux represents the input, and the outgoing radiation from the top of the atmosphere represents an output. In that case, the water vapor feedback loop provides a negative feedback, which reduces the output of radiation.
Fair dinkum luke, I replied to your instructions; why don’t you have a shot at your mate eric who surely has qualified for trolldom for being too clever by half in calling water a negative feedback to OLR; actually he says OLR is an output; I thought AGW was the output; this guy is a nuisance.
“Luke, you’re on the wrong blog. The Lindzen debate is over at Wattsup.
This is the Michael Hammer WV debate and we’re still waiting for anyone to make a single interesting rebuttal to Michael Hammer’s premise after 175 comments.”
In fact the demise of G&T is very pretinent, as Jennifer only recently had a topic that claimed that G&T was something that supported Mike Hammer’s claims. In fact, G&T directly contradict them.
Comment from: cohenite April 3rd, 2009 at 10:27 pm
“Fair dinkum luke, I replied to your instructions; why don’t you have a shot at your mate eric who surely has qualified for trolldom for being too clever by half in calling water a negative feedback to OLR; actually he says OLR is an output; I thought AGW was the output; this guy is a nuisance.”
You seem unable to read with any comprehension.
You confuse the feedback coefficient f in the classic equation for feedback with the CO2 concentration, and now this foolish comment.
The point I was making with calling the OLR the output related to the misapplication of Pompe’s theorem for electronic feedback networks, which said that passive networks can’t amplify power in electronics. I pointed out that this would apply to outgoing radiation which is the analog of the output power, if that is what is claimed to be amplified by the feedback network. The crux of my post wast that this doesn’t apply to Temperature, the variable of interest in the feedback equation, because that is analog of voltage in electronics, and voltage can be amplified by a passive feedback network.
It seems that you persist in wading in with derogatory comments about matters which you don’t fully understand. The less you understand the more you have to say about it.
That is a well known characteristic of the AGW denier blogosphere.
Gordon Robertson, you really need to read a basic astronomy textbook. We can laugh heartily at Velikovsky, in fact, because his ideas were insane and physically impossible. The things that you say are completely unclear to you are rather fundamental, and should become obvious with a tiny bit of study. I wonder why you are so keen to display your ignorance of basic astronomy in such a public way?
Louis Hissink – thought that was the Velikovsky theory that you seem to be an adherent of. But you believe Venus used to be a comet, right? And you somehow believe that its ex-comet nature disproves the idea that CO2 is a greenhouse gas, right? Neither of these things is any less insane than the idea that it came out of Jupiter.
Nick: “Coho, Eric’s formula is correct”
You are very vocal on feedback issues but tell me do you still think a transistor is a good example of a passive system?
will: “But what is powering the microphone?”
What is powering the Sun? A nuclear reaction. What powers a microphone is of course an interesting sound but as far as the amplifier is concerned it’s just a small signal source if you set the gain just loud enough so it doesn’t oscillate the signal the microphone picks up is larger (has more power) than the signal returning to the microphone from the speakers. The output from the speakers needs to be sufficient to energise the microphone for oscillation to occur in order for this to happen there needs to be sufficient gain with a sufficient power supply to supply sufficient energy for positive feedback. You are not going to get this if plug the micrphone straight into the speaker ever.
SJT says:
“In fact the demise of G&T is very pretinent, as Jennifer only recently had a topic that claimed that G&T was something that supported Mike Hammer’s claims. In fact, G&T directly contradict them.”
Are you just waving your limbs, or can you explain how?
I am still waiting for Eric to support his contention that:
“Over a period of years, if the average WV content of atmsphere has increased, the amount of energy required to do this is a negliible fraction of the total heat entering the earth system, from the sun, over that period of time.
The increase in average WV content over the years will certainly cause an increase in the GHE.”
OTOH, I submit that if it takes a forcing of X W/m2 to increase the WV by Y% that forcing must persist at that level for the increased average level of WV. IOW, if the forcing is reduced to a “negligible” level, then the amount of WV in the atmosphere will be reduced accordingly.
Comment from: wes george April 3rd, 2009 at 8:32 pm
“Luke, you’re on the wrong blog. The Lindzen debate is over at Wattsup.”
The Lindzen debate is indeed over. Chris Colose has demolished the premise of Lindzen’s blog about feedback.
http://chriscolose.wordpress.com/2009/03/31/lindzen-on-climate-feedback/
It seems that Lindzen’s argument that the satellite data shows negative feedback, is based on faulty analysis of satellite data that was corrected in 2003, but Lindzen ignored the correction. It seems that he either didn’t know about the correction or ignored it because the incorrect data confirmed his theory.
The part about the Greenhouse effect being real was correct, and wasn’t of course dependent on the faulty data.
The corrected data
cohenite: “Thank you Nick; you are much kinder in your ‘assistance’ than eli or those Deltoid bullies; but just as problematic;”
Indeed over at Niche modelling he present the case of a transistor amplifier as an example of a passive system (one with no internal power source) that “internal” is a very important qualifier though one might refer to it as “auxiliary” that makes no difference but it must be there. in the case of the normal common emitter transistor amplifier the input is applied to the base and the internal power source applied to the collector load impedance. It is an active system and has two (2) energy or power sources. The earth climate system has one. However one can modulate the internal source (who AM transmitters work) and the combined signal will appear at the collector. If however one considers GCRs and solar wind we have such (inverted) modulation and gain is possible of the normally very small TSI variations. This makes Nir Shaviv’s recent work most interesting.
Much as I hate to say it the equation Eric gives is correct for an *amplifier* heroically miss-designed so as to have positive feedback.
http://www.intersil.com/data/an/an9420.pdf
You can see the proper formula for a negative feedback amplifier in eq’n 4 Vo/Vi = A/1+BA where for large A the gain is ~ 1/B (B=Beta). If the sign in the numerator changes the feedback is positive. The equation is right for positive feedback but the question is “does it describe the earth system”. The equivalent input to the the summing junction (Sigma) is the sun falling on the surface with the surface the summing junction the output lower troposphere temperature. The feedback then is the the radiation and conduction precipitation etc i.e. the total downward energy flux which at best that is at best equal to equal to the total flux into the atmosphere. At best B=1 and A=1 (see Misckolczi2007) and we can see what that does to the denominator and the gain will be infinite. If that were the case the atmosphere and water all would have departed the planet long ago.
Given that the planet has faithfully followed the variations in TSi due to Milankovitch cycles the system is quite stable and the equation does not describe the system.
Held and Soden here
http://arjournals.annualreviews.org/doi/abs/10.1146/annurev.energy.25.1.441
come up with something similar in eqn 7.
Fact of the matter the is that the surface temperature dirves the warming of the atmosphere and the radiation component warming the atmosphere is compensated completely by the back radiation but the latent heat and conductive/component are largely dissipated to space so A<1. The latent heat and conductive/convective components are not compensated by downward convection or precipitation so B<1 also but what is crucial here is because A < 1 Vo<Vi and the *heat* (this is important) of the atmosphere cannot exhaust to the cooler surface to do the work of evaporating more water. If it did it would be a perpetuum mobile of the second kind with the heat moving up the potential (temperature) gradient. Then we have to start taking into account the heat lost to space through the atmospheric window.
Comment from: Shawn H April 4th, 2009 at 1:34 am
“I am still waiting for Eric to support his contention that:
“Over a period of years, if the average WV content of atmsphere has increased, the amount of energy required to do this is a negliible fraction of the total heat entering the earth system, from the sun, over that period of time.
The increase in average WV content over the years will certainly cause an increase in the GHE.”
OTOH, I submit that if it takes a forcing of X W/m2 to increase the WV by Y% that forcing must persist at that level for the increased average level of WV. IOW, if the forcing is reduced to a “negligible” level, then the amount of WV in the atmosphere will be reduced accordingly.”
It doesn’t help to wait, if you don’t read the posts that I wrote about it.
Look back for it in this thread.
In case you are not able to find it, I will go over the calculation for a third time.
The task of the solar radiation is to evaporate enough WV to increase the atmospheric content by 14% over a century, which is more or less what the models say it would take for CO2 doubling to occur and achieve the 3C temperature increase aided by the increased WV.
Since the total amount of water vapor in the atmosphere is about 25mm, we need to increase it by 3.5mm. Using a figure for latent heat required to do this of 2260J/g, and the average insolation absorbed by the earth’s surface of 240W/M2, it would take about 9.15 hours of sunshine to do this, out of the 800,000 hours available over the next century. In terms of percent, that is 10^-7% of the radiation absorbed by the earth’s surface over a century.
Please don’t make me repeat it another time. If you disagree, please explain the flaw in what I have done.
Once the temperature has increased and the average WV concentration has climbed, it shouldn’t take any extra energy to maintain it since it is a merely a function of temperature,
and the average global temperature is maintained at constant value, at equilibrium when incoming and outgoing radiation are in balance.
Eric:
“Once the temperature has increased and the average WV concentration has climbed, it shouldn’t take any extra energy to maintain it since it is a merely a function of temperature,
and the average global temperature is maintained at constant value, at equilibrium when incoming and outgoing radiation are in balance.”
Baloney. You have to KEEP adding that extra energy to maintain stasis. But just what is your point? Once the temperature has DECREASED and the average WV concentration has DECREASED, the energy in the whole system has obviously DECREASED, causing a lower average temperature. Which is where we have been for the last 5 years, or so. What happened to all that forcing from OCO and WV feedback? Where did the energy go? Why is it cooler? What is YOUR explanation?
Comment from: Jan Pompe April 4th, 2009 at 2:40 am
“cohenite: “Thank you Nick; you are much kinder in your ‘assistance’ than eli or those Deltoid bullies; but just as problematic;”
Indeed over at Niche modelling he present the case of a transistor amplifier as an example of a passive system (one with no internal power source) that “internal” is a very important qualifier though one might refer to it as “auxiliary” that makes no difference but it must be there. in the case of the normal common emitter transistor amplifier the input is applied to the base and the internal power source applied to the collector load impedance. It is an active system and has two (2) energy or power sources. The earth climate system has one. However one can modulate the internal source (who AM transmitters work) and the combined signal will appear at the collector. If however one considers GCRs and solar wind we have such (inverted) modulation and gain is possible of the normally very small TSI variations. This makes Nir Shaviv’s recent work most interesting.
Much as I hate to say it the equation Eric gives is correct for an *amplifier* heroically miss-designed so as to have positive feedback.
http://www.intersil.com/data/an/an9420.pdf
You can see the proper formula for a negative feedback amplifier in eq’n 4 Vo/Vi = A/1+BA where for large A the gain is ~ 1/B (B=Beta). If the sign in the numerator changes the feedback is positive. The equation is right for positive feedback but the question is “does it describe the earth system”. The equivalent input to the the summing junction (Sigma) is the sun falling on the surface with the surface the summing junction the output lower troposphere temperature. The feedback then is the the radiation and conduction precipitation etc i.e. the total downward energy flux which at best that is at best equal to equal to the total flux into the atmosphere. At best B=1 and A=1 (see Misckolczi2007) and we can see what that does to the denominator and the gain will be infinite. If that were the case the atmosphere and water all would have departed the planet long ago.
Given that the planet has faithfully followed the variations in TSi due to Milankovitch cycles the system is quite stable and the equation does not describe the system.
Held and Soden here
http://arjournals.annualreviews.org/doi/abs/10.1146/annurev.energy.25.1.441
come up with something similar in eqn 7.
Fact of the matter the is that the surface temperature dirves the warming of the atmosphere and the radiation component warming the atmosphere is compensated completely by the back radiation but the latent heat and conductive/component are largely dissipated to space so A<1. The latent heat and conductive/convective components are not compensated by downward convection or precipitation so B<1 also but what is crucial here is because A < 1 Vo<Vi and the *heat* (this is important) of the atmosphere cannot exhaust to the cooler surface to do the work of evaporating more water. If it did it would be a perpetuum mobile of the second kind with the heat moving up the potential (temperature) gradient. Then we have to start taking into account the heat lost to space through the atmospheric window.”
Your post seems to be about the correct equations for transistors, and the application of a transitor analogy to climate. The problem is that you haven’t shown that the analogy applies at all. You seem to be ignoring this problem. There is no validity to any of the arguments you have given until you show that the sytems are exactly analogous.
The positive feedback is for temperature, not power, or energy flux as I have pointed out.
So the transistor analogy using power calculations does not apply at all. Voltage can be amplified by a passive network. Temperature is a quantity in thermal systems that is analogous to Voltage, for what it is worth, and it is the temperature feedback we are examining here.
It doesn’t take any extra energy to maintain an increased average concentration of water vapor in the atmosphere. It does take energy to increase the evaporation rate and apparently you are confusing the two things in your discussion of latent heat.
Comment from: jae April 4th, 2009 at 3:04 am
“Eric:
“Once the temperature has increased and the average WV concentration has climbed, it shouldn’t take any extra energy to maintain it since it is a merely a function of temperature,
and the average global temperature is maintained at constant value, at equilibrium when incoming and outgoing radiation are in balance.”
Baloney. You have to KEEP adding that extra energy to maintain stasis. “But just what is your point?
This assertion is itself baloney. Please explain why energy has to be added. Energy flows in from the sun and an equal amount of energy radiated into space is a characteristic of the equilibrium condition, once the surface temperature increase resulting from the greenhouse effect has been completed.
“Once the temperature has DECREASED and the average WV concentration has DECREASED, the energy in the whole system has obviously DECREASED, causing a lower average temperature. Which is where we have been for the last 5 years, or so. What happened to all that forcing from OCO and WV feedback? Where did the energy go? Why is it cooler? What is YOUR explanation?”Baloney. You have to KEEP adding that extra energy to maintain stasis.”
The rest of your above post about temperature increasing seems to assume things that have not been placed in evidence. What the hell are you talking about? You are confusing surface temperture with total energy in the earth atmosphere system. The earths temperature is known to fluctuate and be chaotic. Equilibrium is a term used to describe long term averages not instantaneuous conditions.
The topic of this thread is not the temperature of the last 5 years, but the claim that WV cannot possibly produce positive feedback. The fact that global temperature goes up and down in the short term doesn’t have any bearing on the theoretical possibility that WV can have positive feedback with temperature.
Besides this theoretical discussion, there is the actual observation of average water vapor content in the atmosphere tracking with short term variations in temperature pretty much as the models predict. Since we have been focusing in Hammer’s blog post, I have neglected to mention this paper.
http://www.nasa.gov/topics/earth/features/vapor_warming.html
“…
With new observations, the scientists confirmed experimentally what existing climate models had anticipated theoretically. The research team used novel data from the Atmospheric Infrared Sounder (AIRS) on NASA’s Aqua satellite to measure precisely the humidity throughout the lowest 10 miles of the atmosphere. That information was combined with global observations of shifts in temperature, allowing researchers to build a comprehensive picture of the interplay between water vapor, carbon dioxide, and other atmosphere-warming gases. The NASA-funded research was published recently in the American Geophysical Union’s Geophysical Research Letters. …”
Eric said:It doesn’t help to wait, if you don’t read the posts that I wrote about it.
Look back for it in this thread.
Well, if you posted this to me before and I missed it, I apologize.
“The task of the solar radiation is to evaporate enough WV to increase the atmospheric content by 14% over a century, which is more or less what the models say it would take for CO2 doubling to occur and achieve the 3C temperature increase aided by the increased WV.
Since the total amount of water vapor in the atmosphere is about 25mm, we need to increase it by 3.5mm. Using a figure for latent heat required to do this of 2260J/g, and the average insolation absorbed by the earth’s surface of 240W/M2, it would take about 9.15 hours of sunshine to do this, out of the 800,000 hours available over the next century. In terms of percent, that is 10^-7% of the radiation absorbed by the earth’s surface over a century.”
LOL! If every 9.15hrs the Earth was adding 14% of WV to atmosphere, the entire atmosphere would be saturated in less than three days.
YOu are way off base here.
As an example of how it works is the following:
A forcing of (let’s say) 4W/m2 causes an increase of temperature by ~1C *and* a corresponding increase of WV of 7%.
If you remove that forcing the temperature will fall by ~1C and there will be a corresponding decrease of WV of 7%.
“Once the temperature has increased and the average WV concentration has climbed, it shouldn’t take any extra energy to maintain it since it is a merely a function of temperature,
and the average global temperature is maintained at constant value, at equilibrium when incoming and outgoing radiation are in balance.”
Does it take any extra energy to maintain the higher temperature? Can you just keep the temperature of the Earth higher without some energetic cost?
Honestly, Eric, are you for real?
Maybe one of the pro-AGW folks can set you straight here.
Eric waves limbs again:
“It doesn’t take any extra energy to maintain an increased average concentration of water vapor in the atmosphere. It does take energy to increase the evaporation rate and apparently you are confusing the two things in your discussion of latent heat.”
Er, Eric, it sometimes rains. The average “life” of water vapor is only 8 days, according to what I’ve read. You have to keep adding energy to renew that vapor, no?
Comment from: Shawn H April 4th, 2009 at 4:00 am
Eric said:It doesn’t help to wait, if you don’t read the posts that I wrote about it.
Look back for it in this thread.
Well, if you posted this to me before and I missed it, I apologize.
“The task of the solar radiation is to evaporate enough WV to increase the atmospheric content by 14% over a century, which is more or less what the models say it would take for CO2 doubling to occur and achieve the 3C temperature increase aided by the increased WV.
Since the total amount of water vapor in the atmosphere is about 25mm, we need to increase it by 3.5mm. Using a figure for latent heat required to do this of 2260J/g, and the average insolation absorbed by the earth’s surface of 240W/M2, it would take about 9.15 hours of sunshine to do this, out of the 800,000 hours available over the next century. In terms of percent, that is 10^-7% of the radiation absorbed by the earth’s surface over a century.”
LOL! If every 9.15hrs the Earth was adding 14% of WV to atmosphere, the entire atmosphere would be saturated in less than three days.
YOu are way off base here.[/quote]
I didn’t claim that the earth was adding 14% of the WV to the atmosphere every 9.15 hours.
But the fact is that the water vapor in the air turns over every 9-10 days, so the reality is not far from that.
http://www.agu.org/sci_soc/mockler.html
“As an example of how it works is the following:
A forcing of (let’s say) 4W/m2 causes an increase of temperature by ~1C *and* a corresponding increase of WV of 7%.
If you remove that forcing the temperature will fall by ~1C and there will be a corresponding decrease of WV of 7%.
“Once the temperature has increased and the average WV concentration has climbed, it shouldn’t take any extra energy to maintain it since it is a merely a function of temperature,
and the average global temperature is maintained at constant value, at equilibrium when incoming and outgoing radiation are in balance.”
Does it take any extra energy to maintain the higher temperature? Can you just keep the temperature of the Earth higher without some energetic cost?
Honestly, Eric, are you for real?
Maybe one of the pro-AGW folks can set you straight here.”
If you would like a higher temperature in your house on a winter day, then you are currently getting, without the expenditure of more fuel, you could try to insulate it better. I am surprised that you wouldn’t know that.
The greenhouse effect is an example of a mechanism that effectively provides added insulation via the atmosphere, between the earth’s surface and outer space. The short wave energy from the sun enters the atmosphere is absorbed by the surface. The surface sends the energy back to space at a rate depending on the temperature given by the Stefan Boltzmann law. The trace gases in the atmosphere absorb and reradiate a portion of outgoing radiation back to the surface, reducing the rate of energy flow into outer space. As a result the earth’s surface grows warmer. No new energy source is required.
Can you really be that stupid, or are you pulling my leg here?
I guess this is an example of the Dunning Kruger effect:
http://en.wikipedia.org/wiki/Dunning-Kruger_effect
The Dunning-Kruger effect is an example of cognitive bias in which “people reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the metacognitive ability to realize it”[1]. They therefore suffer an illusory superiority, rating their own ability as above average.
The less competent you are, the less likely you are to realize your own incompetence, and not recognize competence in others.
In part this is what causes some of the AGW denial, especially when arguments like the Greenhouse effect doesn’t exist, and humans are not responsible for CO2 increase.
Eric:”I didn’t claim that the earth was adding 14% of the WV to the atmosphere every 9.15 hours.
But the fact is that the water vapor in the air turns over every 9-10 days, so the reality is not far from that.”
LOL! If the air turns over, then you have to keep adding more WV to balance the WV that is being taken out.
“The greenhouse effect is an example of a mechanism that effectively provides added insulation via the atmosphere, between the earth’s surface and outer space. The short wave energy from the sun enters the atmosphere is absorbed by the surface. The surface sends the energy back to space at a rate depending on the temperature given by the Stefan Boltzmann law. The trace gases in the atmosphere absorb and reradiate a portion of outgoing radiation back to the surface, reducing the rate of energy flow into outer space. As a result the earth’s surface grows warmer. No new energy source is required.”
Fascinating stuff here, but completely irrelevant to the topic at hand, which is whether you need continual input of energy to keep the average.
Thanks for the psychological diagnosis, but maybe you should focus on your own competence(like how something can turnover and not turnover at the same time).
PLEASE can some pro-AGW guy just let Eric know that he’s wrong. He is making you folks look really bad.
Oops, line above “which is whether you need continual input of energy to keep the average.”
should read:
which is whether you need continual input of energy to keep the average humidity higher.
Sorry about that.
Could I suggest that folks here use a different font for text they are quoting? It is hard to read otherwise. To put something in italics, put a <i> at the start, and a </i> at the end. To be more dramatic, start with <blockquote> and end with </blockquote>.
Shawn: PLEASE can some pro-AGW guy just let Eric know that he’s wrong. He is making you folks look really bad.
I’ve been trying to follow this issue, with great difficulty because people don’t distinguish quoted text from their own!. But Eric is right and the issue is elementary. Water does not, by evaporation, cool a system permanently. If it cools something by evaporating, it warms something else by condensing. It takes a one-off amount of energy to evaporate water to raise the WV content of the atmosphere. This then, through its GHG action, provides a continued heat input. The heat required for the initial evaporation is soon dwarfed by the incoming stream.
Nick, first off, Thanks for the tip about the formatting. I didn’t know what the tags were.
However, what you respond to is not the point at issue.
A forcing of (let’s say) 4W/m2 causes an increase of temperature by ~1C *and* a corresponding increase of WV of 7%.
If you remove that forcing the temperature will fall by ~1C and there will be a corresponding decrease of WV of 7%.
I am saying that to keep WV at the higher amount, the forcing must continue to applied. Eric is arguing that this forcing becomes negligible over time.
Surely you agree that if we reduce the forcing applied to the climate system, the quantity of WV in the atmosphere will also be reduced? If not, under what conditions can the average WV fall?
Now as to your specific point:
Water does not, by evaporation, cool a system permanently. If it cools something by evaporating, it warms something else by condensing. It takes a one-off amount of energy to evaporate water to raise the WV content of the atmosphere. This then, through its GHG action, provides a continued heat input. The heat required for the initial evaporation is soon dwarfed by the incoming stream.
I thought we’d already agreed that if what it warms is higher up than what it cools, then that redistribution *will* act to cool the surface overall. So, on the one hand, you have a slight increase in GH energy with some decrease due to the fact that energy is emitted at a higher average altitude.
Cheers, 🙂
Comment from: Shawn H April 4th, 2009 at 5:05 am
Eric:”I didn’t claim that the earth was adding 14% of the WV to the atmosphere every 9.15 hours.
But the fact is that the water vapor in the air turns over every 9-10 days, so the reality is not far from that.”
LOL! If the air turns over, then you have to keep adding more WV to balance the WV that is being taken out.
It seems that you do not understand the fundamental ideas about the heat budget and the exchange of energy between ocean, atmosphere and outer space. The energy flux into the atmosphere from the earth surface, due to evaporation is about 1/3 of the energy flux arriving from the sun.
However the if the average concentration increases, that doesn’t mean more evaporation has to be taking place constantly. If the evaporation/ precipitation rate remains constant no increase in energy flux is necessary to maintain a higher concentration in the atmosphere.
You apparently don’t understand the difference between rate of evaporation and the concentration in the atmosphere. If you improved your reading comprehension and practiced thinking instead of writing posts disparaging the knowledge of people who know more than you it might help.
Eric wrote
“The greenhouse effect is an example of a mechanism that effectively provides added insulation via the atmosphere, between the earth’s surface and outer space. The short wave energy from the sun enters the atmosphere is absorbed by the surface. The surface sends the energy back to space at a rate depending on the temperature given by the Stefan Boltzmann law. The trace gases in the atmosphere absorb and reradiate a portion of outgoing radiation back to the surface, reducing the rate of energy flow into outer space. As a result the earth’s surface grows warmer. No new energy source is required.”
Fascinating stuff here, but completely irrelevant to the topic at hand, which is whether you need continual input of energy to keep the average.
This was in answer to your question:
Does it take any extra energy to maintain the higher temperature? Can you just keep the temperature of the Earth higher without some energetic cost?
The answer to that is no.
I gave you an example that I hoped you would have the background and intelligence to understand as a prelude to writing about the greenhouse effect, which I feared you would not understand.
I wrote:
If you would like a higher temperature in your house on a winter day, then you are currently getting, without the expenditure of more fuel, you could try to insulate it better. I am surprised that you wouldn’t know that.
Apparently this simple idea was too much for you and you missed it the first time.
Try to read it and think about it this time. Then try to comprehend my simple explanation of the greenhouse effect, or read some other account of the greenhouse effect if you prefer.
Thanks for the psychological diagnosis, but maybe you should focus on your own competence(like how something can turnover and not turnover at the same time).
PLEASE can some pro-AGW guy just let Eric know that he’s wrong. He is making you folks look really bad.
The Dunning Kruger effect lives!
The Chris Colose debate about Lindzen is good value but hardly, as eric hyperbolically declaims, definitive; in fact it raises more questions then it answers concerning the reliability of the data [the old strawman!] as well as the profound issue that even if the corrections are valid that they still have insignificant effect.
The most pressing issue confronting the indefatigable eric and Nick is the fact that water levels in the atmosphere have been declining; how can water be a positive feedback if there is less of it?
RW says: “We can laugh heartily at Velikovsky…”
STJ says: “In fact the demise of G&T is very pretinent…”
Eric says: “…Lindzen’s argument that the satellite data shows negative feedback, is based on faulty analysis of satellite data.” and then he lapses back into Jaberwocky, which goes something like this:
http://www.youtube.com/watch?v=4AQ3Xj49XPE&feature=related
Nick offers a free html-for-dummies course.
Post number 201 and not a single rational pro-IPCC orthodoxy rebuttal to Michael Hammer’s original premise. Pathetic.
It’s enough to disgust even Luke who howls: “The poor little girls ducked it. ooooooo suddenly gone all bashful have we dudes.
You pussies. We’ll take the smoke and mirrors as “oh no we’re caught in the open.” (April 3rd, 2009 at 9:45 pm)
Eric:
If you would like a higher temperature in your house on a winter day, then you are currently getting, without the expenditure of more fuel, you could try to insulate it better. I am surprised that you wouldn’t know that.
Apparently this simple idea was too much for you and you missed it the first time.
Try to read it and think about it this time. Then try to comprehend my simple explanation of the greenhouse effect, or read some other account of the greenhouse effect if you prefer..
It was not too much for me, it just had nothing to do with what I was talking about. I will repost this from a ways back:
A forcing of (let’s say) 4W/m2 causes an increase of temperature by ~1C *and* a corresponding increase of WV of 7%.
If you remove that forcing the temperature will fall by ~1C and there will be a corresponding decrease of WV of 7%.
What I was talking about was if we removed the GH ‘insulation’ or what I would call forcing (in the terms of your example) the temperature and humidity would fall to the baseline. Thus, we need to keep the insulation to keep the temp/humidity higher.
However, for some reason I can’t seem to make this point clear.
Nick “It takes a one-off amount of energy to evaporate water to raise the WV content of the atmosphere.
Nick it takes a continuous supply of energy because as it condenses a large portion of the radiation goes directly to space as it condenses as there is little water above it to reabsorb the radiation.
So is this the result of Wes on a strict diet of minimal rhetorical bullshit. The resultant herniation has now devolved his mind to produce even longer more interminable rants summarising the opposition. zzzzzzzzzzzzz
Atmospheric water levels declining – here’s Cohers with some desperate wiggle watching trying to ignore the major science.
http://www.pnas.org/content/104/39/15248.full.pdf
http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F2008JCLI2274.1
http://www.icsu-asia-pacific.org/resource_centre/Human%20Influence%20on%20Precipitation%20-%20nature06025.pdf
Ok luke; I’m ignoring the Santer effort on principle; this from the Willet paper;
“Trends are consistently larger in the tropics and in the Northern Hemisphere during summer, as expected: warmer regions exhibit larger increases in specific humidity for a given temperature change under conditions of constant relative humidity, based on the Clausius–Clapeyron equation. Relative humidity trends are not significant when averaged over the landmass of the globe, tropics, and Northern Hemisphere, although some seasonal changes are significant.”
But from the Zhang et al letter on p463 Fig 2 shows the only declines in precipitation at latitudes 0-10N and 10-20N
RW:
“Louis Hissink – thought that was the Velikovsky theory that you seem to be an adherent of. But you believe Venus used to be a comet, right? And you somehow believe that its ex-comet nature disproves the idea that CO2 is a greenhouse gas, right? Neither of these things is any less insane than the idea that it came out of Jupiter.”
Perhaps you should do some research on the matter before vilifying commentators here with your misprepresentations based on an obvious unfamiliarity with the subject. What’s your information source? Harper’s magazine?
“The Immanuel Velikovsky Encyclopedia is about the author, Immanuel Velikovsky, and the people and controversy that has resulted from his works. It does not set out to judge whether Velikovsky and his critics were right or wrong, but to document with sources, who said what, and why, and where, and when. There is no doubt that some scientists have labeled some of Velikovsky’s work, pseudoscience or worse, but also others who have acknowledged that Velikovsky made predictions that have turned out to be correct.”
url : http://www.velikovsky.info/Main_Page
Incidentally your comment ” ….believe that its ex-comet nature disproves the idea that CO2 is a greenhouse gas, right?” is one of the best non sequiturs posted here – it makes SJT’s efforts pale by comparison and I thought this was not possible. How wrong I am.
Comment from: Shawn H April 4th, 2009 at 8:40 am
A forcing of (let’s say) 4W/m2 causes an increase of temperature by ~1C *and* a corresponding increase of WV of 7%.
If you remove that forcing the temperature will fall by ~1C and there will be a corresponding decrease of WV of 7%.
What I was talking about was if we removed the GH ‘insulation’ or what I would call forcing (in the terms of your example) the temperature and humidity would fall to the baseline. Thus, we need to keep the insulation to keep the temp/humidity higher.
However, for some reason I can’t seem to make this point clear.
It is now clear to me that you don’t understand what you are talking about. A while back, you wrote a post in which you clearly you misinterpreted the definition of forcing. I called this to your attention quite a ways back, but you apparently ignored it.
http://en.wikipedia.org/wiki/Radiative_forcing
The radiative forcing of the surface-troposphere system due to the perturbation in or the introduction of an agent (say, a change in greenhouse gas concentrations) is the change in net (down minus up) irradiance (solar plus long-wave; in Wm-2) at the tropopause AFTER allowing for stratospheric temperatures to readjust to radiative equilibrium, but with surface and tropospheric temperatures and state held fixed at the unperturbed values. [2]
You claimed that the earth atmosphere system could be in equilibrium, even though forcing was taking place, because the definition used to calculate forcing, assumed that the stratosphere achieved its equilibrium temperature. The state of the earth atmosphere system is decidedly not in equilibrium in such a case. I pointed this out to you but you ignored it.
Apparently now, you are making the false assumption that when the earth system comes to a new equilibrium and the forcing of temperature change comes to an end, that the greenhouse effect, i.e, the insulation, which increased the surface temperature, goes away. That is not the case. The surface temperature remains higher because the greenhouse gases continue to make the atmosphere a better insulator than it was before the increases in greenhouse gases took place. It seems that you do not understand the fundamentals of the greenhouse effect, and refuse to learn.
You are in a catch 22 situation. Your competence will not improve without motivation and work, and so long as you believe you are more competent than you actually are, you will not put in the work to improve your competence. Without an improvement in your competence, you will continue to believe that you are more competent than you are.
Well Cohers – you have not reason for ignoring the prime paper (piggy !).
As for regional effects – well that’s what plagues the stupid uniformitarian style of debate on this blog – a radiative shift in forcing will result in a redistribution of heat which results in changes in circulation systems which you’re seeing. Indeed some areas will get drier and some wetter.
Indeed you addiction to uniformitarianism (must see a consistent universal effect everywhere) is stupefying. Think about it for your own good.
As Gil Compo said last week. Some areas may even cool.
This is why dear chappy climate scientists invented an integrating device called ” a climate model”.
Best of luck divining chooks guts without one ! You’ll be snagged to the rock of empiricism forever and never see the mainland again.
They are there on the first page, from Nick and RW. I supposed you expected something longer, but that was all that was required.
From Nick, again.
AGW hypothesis is based on two mutual exclusive concepts.
Michael Mann needed to show there was no significance Medieval Warming Period and no strong Little Ice Age. It was necessary to create a historically “flat” T-record orthodoxy showing climate had resisted change until the Industrial age came along in order to logically conclude modern climate change is anomalous and therefore anthropogenic.
http://www.grida.no/climate/ipcc_tar/slides/large/05.24.jpg
Paradoxically, Mann’s work implies the Earth’s climate is a powerfully homeostatic system and highly resistant to perturbation, while Hansen claims an extra 150 molecules of CO2 per million will perturb the inherently unstable climate system over a “tipping point” into a climate apocalypse phase shift from which we might never recover.
The same AGW supporters that regular argue there was no MWP (i.e. that climate is far from an unstable equilibrium point) are now here arguing that the Earth’s climate could tip into a new warm period tomorrow to due WV pos feedback!
Of course, if the Earth’s climate equilibrium is more variable — if there really were robust MWP and LIA — then why is a special case, one-off hypothesis — Anthropogenic induced GW — needed to explain only the latest example of climate variability? AGW doesn’t pass the principle of parsimony test.
That’s the larger context surrounding the issue of whether WV has a positive or negative feedback on climate.
Once again we find the AGW supporters are forced to argue from a paradoxical position. The AGW hypothesis requires WV to be a positive feedback on a climate with a tipping point “extremely close to the stable operating point.” Yet for the AGW hypothesis to be remotely useful still requires the historic T-record to show strong climate homeostasis so that any modern climate change is an anomaly to be explained by anthropogenic causes.
So Eric Alder find himself in a catch-22: The usefulness of the AGW hypothesis depends on anomalous modern climate change, but mod climate change isn’t anomalous unless past climate history is robustly stable, but if the climate is inherently stable then catastrophic climate change isn’t possible with so weak a perturbation, so climate must be naturally unstable, but if climate is naturally unstable then what is occurring today isn’t anomalous and the whole hypothesis is falsified.
STJ, you’re being disingenuous. Michael dispatched Nick’s objection within the hour:
I think there may be some misinterpretation of what I was tryng to say in the original post. Nick and Eric, I do uderstand how latent heat effects work and I agree with you Nick that the energy absorbed in evaporating the water is released again when it condenses thus evaporating water does not of itself affect the Earth’s energy balance. For those who subscibe to the view that there is no green house effect because a colder object cannot radiate to a warmer one, I do not agree with you. Green house gases do absorb energy at specific wavelengths in the thermal infrared range and therefore will block some of the radiation from Earth’s surface out to space. Also, it is not true that a cold object cannot radiate to a warmer one, it can and it does, its just that it receives even more energy in return from the warmer object radiating to it. Its also not true that a cold object cannot increase the temperature of the warmer one. If a warm object is radiating to space (4Kelvin) and one intersperses an object at a temperature warmer than space (>4Kelvin) but colder than the warm object, the temperature of the warm object will increase. This is because the warm object is now radiating to a sink at a higher temeprature and receives more radiation from than sink. All of this does not however mean that dangerous AGW is correct.
Coming back to my original post the point I was trying to make is 1) our senses show us that green house effects are very readily discernable over short time scales in localised areas 2) If (1) is correct and we look at a place like Mackay I think itis valid to ask why we don’t get massive thermal amplification or even thermal runaway in that localised area during a summers day when the water vapour content of the air is first substantially increased by the higher temperature and then further increased by very significant increase in humidity plus the greater insolation. Since we clearly don’t see such an effect it raises the question as to whether there is something wrong with the AGW theory. The only answer I can see in the postings is that the heat leaks away laterally. I wonder if that is an adequate explanation to explain the situation on a calm day where there is little updraft.
I also have a genuine question for others. IPCC continuously talks about very long time constants because of the slow rate of overturning of the ocean and that at first sight seems very plausible. Certainly it explains why the deep ocean would respond only very slowly. HOWEVER, lets again go back to what our senses tell us. If we go to the beach on a summers day it is quite common to find the surface of the water is extremely warm yet even 200-300 mm down the water is much colder. In short the water warms from the top and because water is a poor conductor of heat very considerable temperature stratification occurs. Now in the ocean maybe waves churn the surface water up for the top few meters but again our senses tell us that summer to winter there is a very significant change in sea temperature even down a few metres.
The humidity and thus water vapour content of the air is determined by the temperature of the air and the water surface (the temperature deeper down is inconsequential) so why would there be a long time delay between a change in forcing and a atmospheric/surface response. I can easily see that the deep oceans would take a long time to respond but I can’t see why that would impact surface response. If we talk about CO2 rise as a result of warming that comes about from CO2 outgassing from the oceans. That depends on water temperature throughout the oceans which would be governed by the bulk ocean temperature and thus slow but that is a different issue.
Michael our senses show us that green house effects are very readily discernable over short time scales in localised areas
Again, could you clarify this please? I really don’t know what you mean. Is it just referring to back radiation?
Sure Nick; the green house effect relates to an increase in surface temperatures as a consequence of impediment of energy radiation to space. Green house gases do impeded the radiation of energy to spake by blocking such radiation at some wavelenghts and Earth’s surface warms a consequence. We can feel exactly that effect in 1 hour or less on a clouldy versus clear evening. Furthermore, a themometer in a Stevenson screen will also register the difference. We can also feel the effect even if we are sheltered from direct back radiation say by standing on a porch with a roof over it .
Michael “The humidity and thus water vapour content of the air is determined by the temperature of the air and the water surface (the temperature deeper down is inconsequential) so why would there be a long time delay between a change in forcing and a atmospheric/surface response.”
It’s like the insulated saucepan on a slow flame that I mentioned earlier. Only it’s a very slow flame. The AGW 2 W/m2 is like a small light globe every 20 m2 (a large room area). But it’s everywhere and all the time, and the heat ultimately has to escape as OLR.
As you’ve said, seasonal changes are big – maybe 100s of W/m2. And they produce a few deg difference over months, which indicates that mixing is fairly slow over that time. But AGW takes years, and mixing is more effective, though not complete. The heat is spread over hundreds of metres. That’s why we’re looking for ARGO changes of fractions of a degree.
Rough arithmetic – 2 W/m2 will heat 1 m depth of water about 15C in a year (with no losses). But over a year the heat gets mixed way beyond that – to maybe 100 m depth. Then the heating is only 0.15 C/yr. Then there are the losses – evap, more IR etc.
Michael,
Coming back to my original post the point I was trying to make is 1) our senses show us that green house effects are very readily discernable over short time scales in localised areas 2) If (1) is correct and we look at a place like Mackay I think itis valid to ask why we don’t get massive thermal amplification or even thermal runaway in that localised area during a summers day when the water vapour content of the air is first substantially increased by the higher temperature and then further increased by very significant increase in humidity plus the greater insolation. Since we clearly don’t see such an effect it raises the question as to whether there is something wrong with the AGW theory. The only answer I can see in the postings is that the heat leaks away laterally. I wonder if that is an adequate explanation to explain the situation on a calm day where there is little updraft.
As I pointed out earlier, there is a logical flaw in this statement. It appears to assume that the models which project AGW show some kind of runaway, which is not seen. Do you have any evidence that the models are predicting such a runaway? I don’t think the modelers would agree with you that they are. The models show a good agreement with the real climate based on what I have read about their results. So the situation you describe should not raise any questions at all contrary to what you claim.
Since this has turned into such a voluminous thread, you could be forgiven for missing this point which I have made previously, especially since I have been accused of not dealing with your arguments at all by many of the deniers on this thread, most of all Wes.
So what do you say to this?
I would like your take on thi
“…by many of the deniers on this thread, most of all Wes.”
It’s always a pleasure to debate with people who routinely compare your opinions to those who deny the Jewish Holocaust of 1938-45.
Wes, you’ve been complaining, without substance, about a lack of technical response to MH. Well, it’s certainly on now – what are you offerring?
“The models show a good agreement with the real climate based on what I have read about their results.”
I was unaware that the GCMs the IPCC cite “forecast” the temperature plateau (or cooling) of the last decade.
“Do you have any evidence that the models are predicting such a runaway?”
What do you call this, Eric?
http://www.grida.no/climate/ipcc_tar/slides/large/05.24.jpg
Comment from: wes george April 4th, 2009 at 11:32 am
A tipping point is simply an unstable equilibrium point. What the AGW proponents are suggesting is that earth’s climate has an unstable equilibrium point extremely close to the stable operating point. So close, that a change in input of just 2-3 watts/sqM will take us beyond it.
AGW hypothesis is based on two mutual exclusive concepts.
Michael Mann needed to show there was no significance Medieval Warming Period and no strong Little Ice Age. It was necessary to create a historically “flat” T-record orthodoxy showing climate had resisted change until the Industrial age came along in order to logically conclude modern climate change is anomalous and therefore anthropogenic.
http://www.grida.no/climate/ipcc_tar/slides/large/05.24.jpg
Paradoxically, Mann’s work implies the Earth’s climate is a powerfully homeostatic system and highly resistant to perturbation, while Hansen claims an extra 150 molecules of CO2 per million will perturb the inherently unstable climate system over a “tipping point” into a climate apocalypse phase shift from which we might never recover.
The same AGW supporters that regular argue there was no MWP (i.e. that climate is far from an unstable equilibrium point) are now here arguing that the Earth’s climate could tip into a new warm period tomorrow to due WV pos feedback!
Of course, if the Earth’s climate equilibrium is more variable — if there really were robust MWP and LIA — then why is a special case, one-off hypothesis — Anthropogenic induced GW — needed to explain only the latest example of climate variability? AGW doesn’t pass the principle of parsimony test.
That’s the larger context surrounding the issue of whether WV has a positive or negative feedback on climate.
Once again we find the AGW supporters are forced to argue from a paradoxical position. The AGW hypothesis requires WV to be a positive feedback on a climate with a tipping point “extremely close to the stable operating point.” Yet for the AGW hypothesis to be remotely useful still requires the historic T-record to show strong climate homeostasis so that any modern climate change is an anomaly to be explained by anthropogenic causes.
So Eric Alder find himself in a catch-22: The usefulness of the AGW hypothesis depends on anomalous modern climate change, but mod climate change isn’t anomalous unless past climate history is robustly stable, but if the climate is inherently stable then catastrophic climate change isn’t possible with so weak a perturbation, so climate must be naturally unstable, but if climate is naturally unstable then what is occurring today isn’t anomalous and the whole hypothesis is falsified.
You have here a marvelous piece of logical masturbation. The creation of a false dichotomy on top of a falsification of history.
The first hockey stick paper was published in 1999. The basis for predictions of global warming has its roots in the greenhouse effect, and the first general circulation models of the mid 1970’s.
The earliest projections of global warming due to CO2 were made by Arrhenius in 1896, after many long months spent on hand calculations which represented the earliest attempts at projecting future climate by modelling. James Hansen’s 1981 paper was a seminal event in the history of global warming theory. All of this was in place before the hockey stick.
Some of Hansen’s best work was the explanation of the Vostok ice core data, which detailed the Milankovich cycles and the role of albedo and natural CO2 increases in the amplification of the initial changes in insolation due to the earth’s axis. It is the very same sorts of models that he used to explain the Vostok ice core data that are used to project the progress of global warming due the human emisisons of GHG’s.
There is no dichotomy at all between paleoclimatology and the model projections such as you have argued.
Comment from: wes george April 4th, 2009 at 1:05 pm
Eric wrote:
“The models show a good agreement with the real climate based on what I have read about their results.”
I was unaware that the GCMs the IPCC cite “forecast” the temperature plateau (or cooling) of the last decade.
“Do you have any evidence that the models are predicting such a runaway?”
What do you call this, Eric?
http://www.grida.no/climate/ipcc_tar/slides/large/05.24.jpg
The term such “a runaway” was used to refer to the hypothetical runaway of the current daily temperatures that Michael Hammer imagined would be the result of AGW theory.
The increases in future global projected temperature of a few deg C, by the GCM’s have no relationship to the point that I am making about the falsity of Michael’s imagined, Hypothetical AGW theory results which supposedly give runaway of daily temperatures by 10’s of degrees C.
Sorry Wes, but your point is bogus once again.
Eric Adler,
Arrhenius didn’t even get the wavelengths right. Our current idiot savant who backstops Gore, James Hansen, is little better.
Why don’t you throw some more of those excellent peer reviewed papers at us also!! Oh yeah, you DID mention the Vostok Ice Cores, a perfect study in Confirmation Bias!!!
HAHAHAHAHAHAHAHAHAHAHA
nick stokes,
“Rough arithmetic – 2 W/m2 will heat 1 m depth of water about 15C in a year (with no losses)”
That is 1 cubic mater of water, heated by 2W/m2 to 15C? in one year, constant heat source, no losses or mixing?
Can I please buy that heater?
Eric Adler,
you DO realise that an AMPLIFICATION circuit needs a POWER SUPPLY to AMPLIFY the SIGNAL?!?
Or is this some more of that special MODEL PHYSICS?!?!?!
HAHAHAHAHAHAHAHAHAHAHAHA
My apologies to Michael Hammer for giving Eric Alder, et al an excuse to digress away from the topic de jure. They seem to be willing to take on anything but your premise.
Please, Eric, Nick direct your comments to the topic. Michael Hammer said about an hour ago:
Comment from: kuhnkat April 4th, 2009 at 1:34 pm
Eric Adler,
you DO realise that an AMPLIFICATION circuit needs a POWER SUPPLY to AMPLIFY the SIGNAL?!?
Or is this some more of that special MODEL PHYSICS?!?!?!
HAHAHAHAHAHAHAHAHAHAHAHA
If one constructs a thermal analog of an electrical circuit, current in amps is analagous to energy flux in watts. The thermal analog of Voltage is temperature. Voltage can be increased without an special power supply to amplify the signal.
Here is a simple circuit which shows this.
http://palantir.cs.colby.edu/maxwell/classes/e12/S04/labs/lab01/
In the case of the electrical analog where one has a constant current source, one needs only to increase the resistance and the voltage will increase.
In the case of temperature adding insulation to a system can increase the temperature.
Your laughter is the mad cackling of the ignorant being led by the ignorant.
Comment from: wes george April 4th, 2009 at 1:42 pm
My apologies to Michael Hammer for giving Eric Alder, et al an excuse to digress away from the topic de jure. They seem to be willing to take on anything but your premise.
Please, Eric, Nick direct your comments to the topic. Michael Hammer said about an hour ago
Wes,
You are flattering yourself. You did not divert Nick and me from commenting on what Mike said.
I was able to reply to Michaels points and your points recently. Maybe you want to divert the attention back to Michael’s posts because you embarrassed yourself with your bogus history, illogical dichotomy, and confusion about what was meant by runaway temperature.
Once again you have not kept up with the posts. For the second time are falsely accusing me of not replying to Michael’s talking points. Apparently you are so focused on your own stupid talking points and my replies, that you missed what I said about Michael’s idea a second time.
Please go back and read Nick’s and my posts on page 22. It was not that long ago:
http://jennifermarohasy.com/blog/2009/04/role-of-water-vapour-in-climate-change/?cp=22#comments
Nick and I replied to both points that Michael made in the initial post, that he recently reiterated. Stop accusing people of not responding when you have neglected to look to see if they have. I am tired of repeating the same post over and over because people have overlooked it.
Oh, I’m sorry Eric, I didn’t really understand that the factual errors and unsupported claim of it’s-illogical-because-I-said-so was all you had to regale us with.
Does this mean that’s it. You’re done? I’m disappointed. You sounded so well informed.
eric’s trolling continues; AGW hysteria is often dismissed by its spruikers as hyperbole from sceptics; that AGW does not predict a Venus syndrome effect and to say so is a gross misrepresentation;
http://climatechangepsychology.blogspot.com/2008/12/james-hansens-agu-presentation-venus.html
Just click on the pdf presntation and go to slide 22; this is archetypal Hansen and AGW doom-saying with sophistry to back it up; such as the repeated mantra that “Equilibruim Climate Sensitivity is 3C for2xCO2 [“nailed” exhorts Hansen]; this is demonstrably wrong as is the Hockeystick fraud used to support the idea of an equilibruim; legal redress must occur soon; I especially like the Faustian bargain on slide 11 with humanity “dragged to its doom’. Maybe eric is a demon come to give us a taste of what our doom will be like.
Eric
Sorry Eric you show yet again that you don’t understand it current does not drive the voltage. What on earth do yo think drives that current on a constant current source? The voltage can on increase to the source voltage when the current source is looking into an open circuit.
Like wise temperature drives heat flux not vice versa.
Michael Hammer “For those who subscibe to the view that there is no green house effect because a colder object cannot radiate to a warmer one, I do not agree with you. Green house gases do absorb energy at specific wavelengths in the thermal infrared range and therefore will block some of the radiation from Earth’s surface out to space. Also, it is not true that a cold object cannot radiate to a warmer one, it can and it does, its just that it receives even more energy in return from the warmer object radiating to it. Its also not true that a cold object cannot increase the temperature of the warmer one”.
Michael…you need to brush up on AGW theory. The basis of AGW theory is that CO2, in particular, absorbs IR from the surface, then back-radiates it to the surface. So far, so good…no arguments. The example you gave has one major problem, you refered to an independent, cooler, source of heat interspersed between the surface and the atmosphere. The heat that warms the CO2 is not independent, it comes from the surface. So, the heat back-radiated is directly dependent on the surface emissions.
When that narrow-spectrum IR is radiated from the surface, it is a loss of energy. Anything back-radiated is doing nothing more than making up for that loss, it is not adding to the surface heat. The energy transport mechanism is not lossless either. Air is an effective insulator to energy tranpsort via heat, and there are losses between the surface and the atmosphere, then between the atmosphere and the surface. If there is any feedback in that exchange, it is a negative feedback. That’s why the notion that the cycle increases the temperature of the surface contravenes the 2nd Law.
Clausius stated that a cooler body cannot warm a warmer body that warmed it to a temperature higher than the warming body was in the first place. If the surface is warming CO2 in the atmosphere, which is at a cooler temperature, and that CO2 radiates it’s absorbed heat back to the surface, it cannot warm the surface to a higher temperature than it was when it heated the CO2. That’s why the modelers were so intent on finding a hot spot in the atmosphere as a signature that increasing CO2 was absorbing more surface IR.
For that reason, the atmospheric CO2 cannot warm the surface to a higher temperature than what it was warmed by solar radiation. If it could, we’d have a perpetual motion machine. The solar radiation heats the surface, the surface heats the atmospheric CO2 which radiates back to the surface. The AGW mob are adding the back-radiated heat to the solar radiation to get an increase in surface temperature due to the solar radiation being increased by the amount of back-radiation. Does no one understand that the back-radiated heat came from the Sun in the first place? It’s not an independent source, therefore it cannot be added again to incoming solar radiation.
The analogy you gave is an independent source. So, if we had another star nearby, maybe a lot smaller than ours, and they both shone on the Earth’s surface, the energies from both could be added. But if the back-radiated source comes from the surface, after being heated by solar radiation, it is not an independent source. It is merely feeding back energy that has already been supplied by the Sun. The AGW mob are claiming that energy can be stored by the atmosphere and fed back as an additional energy to that of solar radiation when in fact that back-radiated heat came from the Sun in the first place..
To complicate matters, the IR radiated from the surface is a small subset of the solar radiation and at a much lower magnitude. The back-radiated energy is at a different frequency than that radiated from the surface, and it’s an even smaller subset of IR and magnitude. Not only that, the anthropogenic quantity coveted by the AGW theory is a tiny subset of the atmospheric CO2 density which in turn is a tiny amount of the overall atmospheric density.
At a density of 380 ppmv, which represents all atmospheric CO2, the anthropogenic density is a theoretical 11.4 ppmv. We are talking 1 molecule of ACO2 per 100,000 molecules of air. When you consider that emissions from the surface are radiating from many different altitudes and in many different directions, how is that 1 molecule of ACO2 per 100,000 of air going to trap anything? Even the 38 molecules of CO2 per 100,000 of air could not possibly trap all surface emissions.
That’s looking at the problem subjectively. What G&T have done is evaluated the problem at a quantum level. They claim it is nonsense to regard a quantity of CO2 in the atmosphere, having a volume with sides of molecular dimensions, as a blackbody (cavity resonator). They also claim it is nonsense to evaluate photon paths with a one-line diagrams as the AGW mob find it so easy to do. They claim such an analysis involves complicated vector fields and Feynman diagrams. That translates to the fact that the Boltzmann constant does not apply in the atmosphere as is, requiring it to be adjusted to the non-blackbody conditions.
The point I am trying to make is that the AGW mob have simplified the problem out of all proportion. The energy balance quantities were simply grabbed out of the air and NASA has admitted there are quantities that cannot be corroborated. In the textbook, Fundamentals of Atmospheric Radiation, there are several detailed chapters on photon emission, absorption, scattering and polarization alone. They claim the notion of the atmosphere as a blanket trapping heat is sheer nonsense. Between them and G&T, I’m taking that to mean the problem is so complex that it cannot be reduced to a one-line diagram and the simple addition of heat quantities.
That’s my story and I’m sticking to it.
Well put Gordon.
“Comment from: gavin April 2nd, 2009 at 10:43 pm …..To cohenite & co: if you can’t quickly explain why the sea around the East Coast of Australia and probably just about everywhere else is still rising, then I can go back to my bed!”
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…. Ok Gav. check this out then.
http://wattsupwiththat.com/2009/03/19/despite-popular-opinion-and-calls-to-action-the-maldives-is-not-being-overrun-by-sea-level-rise/#more-6338
…. and right down the bottom of the article you will notice a photo and this description too……..
“The tide gauge and GPS installation at Burnie (NW Tasmania). The tide gauge has been running since 1992 and has been used for absolute calibration studies on the TOPEX/Poseidon and Jason-1 satellite altimeters”
….. As you can see Gavin. The Tide gauge for this all important calibration is sitting on a rickety old jetty that has no baseline studies to see if that jetty is not sinking or otherwise compromised……. Remember we are only talking mere millimeters per year or decade measurements…. !
Data collection for the hypothesis of AGW has a lot of problems….. It leaves a lot to be desired, you must admit.
Hi Nick and Eric, sorry to be so long replying, I had to go out. Firstly, your point Eric that the posts are so voluminious I missed your earlier comments. Indeed they are, every time I log on there seem to be about 50 more and I am having enormous trouble keeping up between full time work and other home activities so my apologies and let me try and address your comments now.
Eric to take your points first. You state that the models do not predict a “tipping point”. In what I write I am not specifically targetting models. There are many of these and I freely admit I do not know what every one of these predict. Rather I am commenting about the presentation of AGW to the public and the politicians, dominated by the pronouncements of the principle AGW advocates. Now I don’t think you can deny that James Hansen and Al Gore are the two most prominent AGW advocates and in fact I would claim that to the public they are the de facto voice of the AGW movement. Nor is Hansen just a spruiker he is after all the controller of the climate data that IPCC relies on (I cofess I wold have liked to say controller and manipulator but I am sure you would strongly disagree with the second descriptor). In the last two weeks I have read articles wherein Hansen claimed the planet is very close to a tipping point leading to irreversible climate change. If the models don’t predict such a tipping point, where is Hansen getting his information from. If the claim is unfounded it is not just an exaggeration, it is a significantly different and far more serious assertion. If Hansen’s comments are justified then my article stands in opposition. If Hansen’s claims are unfounded then I think it is time the AGW movement controls Hansen and ensured that what is claimed is substantiable, because the movement is being judged and evaluated by what Hansen and Gore claim.
By the way, there may be some who throw invective around and make claims like the one you referred to in the thrid paragraph of your post. I try hard not to do so and I would like to state for the record that I do not support such actions. If someone thinks I have, I apologise. I believe this subject can only be resolved by serious and wide ranging debate which is what I am trying to foment and I thank you for your interest.
Now moving further. Could the sideways and upwards dispersal of the extra energy prevent the siuation I have been suggesting. The correct solution would be to cary out a mathematical analysis but the the reality is that this would be so complex few people active here would be able to understand it (probably including me). Next best, can we get some sort of quick “engineering approximation” which gives us some idea. I think maybe we can. There is another situation where a local region is heated differentially compared to its surroundings, one very prominently discussed in relation to AGW. It is the urban heat island effect – a city is heated by the extra energy emitted and by the presence on large amounts of masonary and absence of trees. Now we can easily see the urban heat island does exist, simply compare the temperature as reported each evening for the city centre compared with outlying suburbs. City centres are hotter. I have seen reports suggesting for example that Tokyo centre is 7 degres hotter than the outlying areas and something similar for New York. Melbourne where I live looks like it is 2-3 degrees hotter. Now is this not an example of a region which is receiving extra energy locally and that effect is showing up in higher local temperatures. Why is that any different from the scenario I describe? They are both local, probably over about the same region and the time scales are similar. Proof? no, strong suggestion? I think so. Nor is the impact of the additional water trivial. Consider, the humidity in an arid region could well be around 20% while in MacKay it could easily get to 80%. Thats 4 times the amount of water vapour at the same temperature or two doublings. Someone in this thread suggested 15 watts/sqM per doubling for water vapour. If so that would be an additional energy input of 30 watts/sqM – far from trivial.
Nick I read your comments. From what you state I would expect that the ocean surface would not warm significantly summer to winter and that the mxing would give a smooth gradient all the way down. But I understood that there is a layer in the ocean called the thermocline which separates the warm surface water from the cooler water below. The presence of a thermocline layer would seem to suggest to me poor mixing at this level otherwise the layer would be destroyed. If so it is really only the water above the thermocline which has to be considered and I thought the temperature of this changed significantly summer to winter. If I have got all this wrong please tell me.
Gordon, I have no idea if you’re right, but in contrast with any of Eric Adler’s rants I can actually understand and follow your reasoning. I wonder why? Maybe, it’s because English isn’t your second language…
“The AGW mob are claiming that energy can be stored by the atmosphere and fed back as an additional energy to that of solar radiation when in fact that back-radiated heat came from the Sun in the first place…”
Question from the peanut gallery: Is that what they are really saying? Or is it more like the GHG slow the reradiation of energy back to space, so that because the extra GHG weren’t there before the climate will phase shift to a new more energetic equilibrium? But they need WV to positively feedback if they want to ramp up alarm for full blown climate catastrophe, because 38 molecules of CO2 per 100,000 by itself isn’t going to cut it?
Jan, I am becoming very doubtful that you know anything of electrical circuit theory. Eric’s statement is perfectly routine. You yourself quoted Thevenin’s theorem a few days ago. This says that a source of DC power with impedance R can equally be regarded as a voltage source (battery) with R in series, or a current source with R in parallel. And seen as a current source, the voltage is proportional to R, just as Eric said.
Comment from: wes george April 4th, 2009 at 4:16 pm “…….. Question from the peanut gallery: Is that what they are really saying? Or is it more like the GHG slow the reradiation of energy back to space, so that because the extra GHG weren’t there before the climate will phase shift to a new more energetic equilibrium? But they need WV to positively feedback if they want to ramp up alarm for full blown climate catastrophe, because 38 molecules of CO2 per 100,000 by itself isn’t going to cut it?”
Yep. You got it wes….. But remember…. 37 of those 100 000 molecules of air are natural CO2… Only 1 is anthropogenic…. (I’ll add a few exclaimation marks for theatrical effect now) !!!!!!!!!!!
It is certainly a mighty molecule, this mutant ninja CO2 molecule we created in the evil furnaces of industry;-)
Eric Adler “If one constructs a thermal analog of an electrical circuit, current in amps is analagous to energy flux in watts. The thermal analog of Voltage is temperature. Voltage can be increased without an special power supply to amplify the signal”.
“If one constructs a thermal analog of an electrical circuit, current in amps is analagous to energy flux in watts. The thermal analog of Voltage is temperature. Voltage can be increased without an special power supply to amplify the signal”.
I don’t mean any disrespect, but your analogies leave a lot to be desired. If you’re constructing a thermal analog, you’d need atoms in substances at two different energy levels. Those energy levels would be equivalent to voltage levels and the current between those levels would be analogous to heat flow. The medium between the energies, like air in the atmosphere, would be resistance.
You’re making it sound as though voltage is dependent on current, which is not the case. It’s true that a current running through a resistance creates a voltage drop across the resistance but that current was initiated in the first place by a voltage. When you talk about constant current sources, you have to be careful because they are theoretical devices that imply current can be injected into a circuit without a driving voltage. That’s not true. The constant current source is created using feedback control but the current itself comes from a voltage source, like a battery or a generator.
Don’t forget that current is a flow of charges, which is essentially a flow of electrons, which are the only carriers in a copper-wired circuit. Those electrons won’t move unless there is an electric field to drive them, and such an electric field is a voltage source. So, when you talk about voltages rising due to a constant current source flowing through a variable resistor, you are not talking about the same thing as a voltage from a power supply driving an electronic amplifier. The current from the constant current source came from a power supply. There is no such thing as an independent current source.
In an amplifier, amplification, or gain, is totally dependent on the power supply. A transistor operates by varying a larger current between it’s emitter and collector (its output circuit in a conventional common-emitter amplifier) in response to a smaller signal between its base and emitter. The larger current is supplied by the power supply, and that’s why you don’t get something like amplification for nothing.
The amplification is dependent on doping in the transistor’s silicon, semi-conductor structure, where carriers (electrons in an NPN transistor) are seeded based on the desired amplification. However, the amplification in the transistor is merely a means of transfering control from the input to the output circuit in such a ratio that the output circuit is carrying a higher current based on the smaller input current. The output current has to be supplied from an external source since that larger current is not produced within the transistor..
It’s not necessary to understand the physics involved if you accept that a transistor is essential a variable impedance (resistance) that is controlled by a small input signal. The impedance is connected across the power supply (voltage) with the load between the transitor collector and the power supply. As the transistor changes impedance due to the input signal, it varies the voltage drop across it and that affects the attached load. In the case of a digital circuit, the transistor simply turns on and off rather than varying.
It is critical that the power supply voltage remains constant. Modern amplifier power supplies are regulated to a fraction of a percent. The voltage is rock solid. Any transistor circuit is an amplifier of some kind, even if the gain is less that 1 (unity). It cannot operate without a constant-voltage power supply. In audio or control circuits, where feedback is employed, the output current comes from the power supply. Without that constant voltage, the circuits would not work, or they would be unstable in the case of a varying power supply.
That’s why I am questioning the notion of CO2 being able to provide a positive feedback that increases the surface temperature. Where is the gain coming from? Some people claim it comes from the solar radiation but that makes little sense to me. When the surface radiates IR to the CO2, that represents a loss of energy on the surface. That lost energy is later back-radiated in part, because there are losses in the atmosphere. That already represents a negative feedback. The back-radiated energy is doing nothing more than replacing a portion of the energy it got from the surface, which got it from the Sun.
Clausius was talking about a closed system. The earth is being heated by an external energy source. The surface is not being made “hotter” than it orgininally was, it is just cooling down more slowly than it otherwise would have, given that it is being continually heated.
Where you got the idea the “hot spot” fits into all this comletely baffles me, and I am sure the modelers would be completely baffled too.
Gordon; I do understand where you are coming from, many students (me included many years ago) have gone through such thought processes which is why so many find physics such a confusing discipline to learn. Non the less, I have to totally disagree with what you wrote. May I suggest a different perspective whcih might help.
Imagine we create a very hypothetical situation, imagine we cram all the green house gas into a layer some distance above the surface. Between the surface and the green house layer we draw a dotted line. We are going to separate the bit below the line and the bit above the line and treat them as two separate systems. Now the surface, the bit below the line receives energy from the sun coming from above the dotted line and in turn radiates upwards through the dotted line. The surface has no idea where the energy is going to, it is not intelligent, it simply radiates. Now if there was nothing above the dotted line that radiated energy would go off to space and never return.
OK now think of the bit above the dotted line. It receives energy coming through the dotted line from below. It absorbs that energy and in the process gets warmer. Since it is not at absolute zero it also radiates both upwards to space and downwards towards the dotted line. It is also not intelligent and has no idea where the energy is going, it simply radiates. But the radiated energy travelling downwards cannot spontaneously disappear. Once emitted it continues on through the dotted line until it strikes the surface. The surface knows nothing about the layer above the dotted line, it simply receives additional photons through the dotted line so the total energy it receives is increased. Earlier, someone commented about my example with a thermos flask that I was confusing reflecton and emission. True they are different but from the point of view of a cool surface returning energy to a hot surface they amount to the same.
The cool layer above the dotted line is a source just as the star you postulated would be a source. It is a source because of its temperature just as a star is a source because of its temperature. It makes no difference how that temperature came about. What is true and different between the two is that if the bit below the dotted line was removed then the bit above would cool down and progressively radiate less and less. Eventually it would reach absolute zero and cease to be a source.
Believe me I do know how hard it is to get ones head around all this. I still remember my conflict from 40 years ago but trust me I do know what I am talking about on this. Remember, I am not an AGW believer tryin to push a line. I am, like I think you are, a skeptic but I am firmly convinced that for the future of our society we need to get to the truth behind all this.
On another point you talk about loss in energy travelling through the air and comment that air is a poor transmitter. This is not correct. I think you are confusing conduction with radiation. Air is indeed a poor conductor of heat but for radiated energy unless there is a medium that aborbs such as a green house gas or dust, radiated energy will pass with essentially no loss at all.
Michael,
I believe the thermocline is just a descriptor of where the temperature gradient is steepest. If you look at the wiki story you’ll see a plot of the tapering of temp in a tropical sea, which tapers slowly to 100m, then more rapidly over the next 100m. The reason is that waves stir that top 100m (less so as you go down), while the mode of heat transport at depth is dominated by horizontal transport bringing cold water from high latitudes faster than heat diffuses from above. (There’s a bit of a lesson there about horizontal transport).
The steady temp story is different in temperate oceans, where the tapering is more gradual (and the seas often rougher). The wiki article on mixing layers says that they may extend to 2000 m in the Labrador Sea. So my rough arithmetic based on 100m has some reality.
Your UHI arithmetic is interesting. I was wondering along these lines myself. Globally, we use about 3kw per person (average over adult, child, poor or rich, 24/7). If you have a Western city with a million people per 100 sq km, dissipating maybe 5kw each (richer), that is about 50 W/m2. It’s much higher that AGW, and not too much less than the main fluxes. So a few degrees of UHI is not so surprising.
Thanks for that Michael. But you lost the peanut gallery with:
“What is true and different between the two is that if the bit below the dotted line was removed then the bit above would cool down and progressively radiate less and less. Eventually it would reach absolute zero and cease to be a source.”
Why wouldn’t the GHG layer (the bit above the dotted line) continue to be warmed by the sun, like a cloud in space? Probably a stupid question.
And Nick, is that 3kw per person per minute, hour, day?
wes george “Question from the peanut gallery: Is that what they are really saying? Or is it more like the GHG slow the reradiation of energy back to space…”
My understanding is that both are being claimed, depending on who you talk to. However, the theory that water vapour is increasing due to a positive feedback, from a GHG-warmed surface, has to come from that theory alone. Trapped heat explains nothing but the greenhouse effect itself.
In the textbook, the Fundamentals of Atmospheric Radiation, they call the blanket theory, or trapping theory, a bad metaphor at best, and at worst, just plain silly, because you can’t distinguish between photons. The photon is an attempt to treat radiation as a discrete particle, but no one knows if radiation is a wave or a particle. In the case of a CO2 molecule, it is more convenient to think of radiation as a discrete particle, like a photon, but in reality, no one has a clue what is going on. No one knows what IR radiation is and that’s why it’s damned silly to talk about trapping it. That’s also why the notion of a greenhouse effect is silly.
I have no problem conceding that something is warming the planet from where it would be if we had no oceans or atmosphere. To arrive at a conclusion that heat radiated from the surface is being trapped, as in a real greenhouse, is plain silly.
Hi Nick;
An interesting calculation indeed, I like it. 1 million people in 100 sq km is 10^6 people in 10^8 sq M or 100 sqM per person. I don’t think population density gets to that level in Australia but it might in other cities with lots of high rise apartments. Also I am not sure about the 5kw per person but I realise its a back of the envelope calc so lets accept it as a somewhat rough but indicative estimate. It’s also comparable to the extra energy from the water increase that I estimated. This would mean we should see at least a 5 degree increase (possibly 7 if we compare with Tokyo) from the extra humidity. Question is do we? I don’t think we do.
With regard to your thermocline data I don’t know enough to comment further. I will have to do some reading up, will tray and do so in the next few days.
cheers
Wes; yes it would, I was focussing on the bit below the dotted line and the impact of its removal. In fact though, very little of the energy received from the sun is in the thermal infrared range (the sun is so hot that most of its radiation is a much shorter wavelengths) . So if the GHG only absorbs thermal infrared then there will be little energy to absorb although you are right it will abosrb some and will not cool down to absolute zero. Consider me suitably corrected
Gordon; I fear we are going to have to simply agree to disagree, there are simnply too many issues for me to go through. Suffice it to say we do know what infrared radiation is, and how it is abosrbed by GHG molecules. Just to give you an idea, among other things I design spectrophotometers. These indentify elements by their characteristic absorption lines (no not in the infrared – usually in the ultraviolet although we also build spectrophotometers that analyse for molecules based on long wave absorption). This is what spectroscopy is all about. The least sensitive class of these instruments are called atomic absorption instruments and they can detect a particular element down to concentrations in some cases as low as about 10 parts per billion (thats 0.01 PPM) over a path length of 5 cm! The atmospheric column is more than 5 km 10^5 times longer and we are talking about concentrations 100’s of time higher.
Yes wes, this is becoming a mess; insolation’s spectrum is this;
http://en.wikipedia.org/wiki/File:Solar_Spectrum.png
So even if the surface stopped emitting the atmosphere would be warmed due to GHG absorption; I’m beginning to think the ‘science’ of AGW is a dog’s breakfast and while the discussions are sometimes fascinating, for those of us in the ‘peanut gallery’ who want this whole debacle to black hole itself so we can go back to reading Phantom comics, the real action is with the results/proof/real things [sic] caused by AGW not so much AGW theory; I’ll put that to Nick who seems to have more sense and decorum than most warmers; so Nick, show us the money.
No point complaining about it, or those who study it. That’s just the way it is. If all we do is wait to see what happens, then it will be too late to do anything if it turns out to be the predicted disaster. We do have the models, and, as impefect as they may be, they are our only guide to what is likely going to happen. Once again, no point blaming the scientists for that, that’s just how things are.
Wes “And Nick, is that 3kw per person per minute, hour, day?”
Well, Wes, if that’s your technical contribution, I think we’d better look elsewhere.
No SJT models are not the only things we have nor even the best things we have. We also have theoretical analysis which is what I am trying to do, we also have historical analysis which many others are addressing and we also have real word comparisons between models and reality to test the models which others are also doing. I contend that these do noto agree with model predictions. I contend the weight of evidence is against AGW being a danger and that before we seriously damage or destroy our society we get a better handle on whether such action is necessary.
The AGW movement has ben shown to manipulate historical data in unsupportable ways so as to justify its claims. Manns hockey stick is one example but I am more worried about Hansens almost continuous unexplained revions to the historical temperature record and always in such a way as to amplify the warming trend. Why are all corrections one way? Why is there such a difference between his record and the raw satellite data? When the raw data shows no temperature trend and all the trend in the corrected results flow from those correction I start ot get extremely worried. These actions do not breed confidence, rather quite the opposite. The essence of science is to be honest, impartial and let the results fall according to nature not individual manpulation.
Then they rely on the precautionary principle. From what I have read they similarly relied on this when arguing against DDT and the result was 50,000,000 extra deaths from Malaria mostly children. I find that unspeakable and indefensible. Suspicion is no where near enough. It’s not enough in law and even more its not enough now, we need something better. To the best of my ability thats what I am trying to contribute to finding.
End of ditribe (I know it has nothing directly to do with this debate and I apolgies to that extent but it is how I feel).
Michael hammer “Non the less, I have to totally disagree with what you wrote”.
Michael…I have no problem with your critique, but there are inconsistencies in it. Before I go on, let me say that I am basing my arguments on those of two working physicists, both of whom work in related fields. Gerlich teaches vector and tensor math in physics and Tscheuschner works in a directly related field using heat theory. The math is directly related to the study of heat fluxes in the atmosphere. Those are the guys you have to convince, not me. The other main source I use is Fundamnetals of Atmospheric Radiation, where one of the author’s, although now retired, taught meteorology at university level. His name is Bohren, and I find his understanding of physics to be top class.
The first inconsistency with your model is that you have not accounted for the losses at the surface. The CO2 in the atmosphere is acquiring energy that the surface is losing. So, that ball of CO2 you have above the dotted line represents a loss of surface energy. When it gives it back, it is merely making up for the loss, not adding to the solar radiation.
The second discrepancy is your claim that radiation is not affected by the atmosphere. How do you explain the difference between the solar radiation at the outer edge of the atmosphere and the solar radiation at the surface? Furthermore, since the solar spectrum is roughly 50% in the IR band, how much of the solar radiation is absorbed by the GHG’s on the way in, and how much does that warm them? In other words, how much of that ball of CO2 above the dotted line was warmed by the solar radiation, and how much of the CO2 emissions is actually from solar energy?
I might add a third inconsistency. You haven’t answered the contravention of the 2nd Law. How does a cooler body warm a warmer body that warmed it to a point where the warmer body gets warmer? Thought experiments are fine, and I realize you don’t buy into the AGW model, which I appreciate, but I have yet to hear a convincing argument that the 2nd law is not contravened.
Thanks for the reply.
Michael hammer “I fear we are going to have to simply agree to disagree…”
Fair enough. I appreciate you providing your insights and I have no problem whatsoever with disagreement. Given your degree in engineering, and having done a few years myself, I realize what you’ve been through. Engineering is a tough grind that involves almost double the time and effort of most disciplines. I take my hat off to you.
“Suffice it to say we do know what infrared radiation is, and how it is absorbed by GHG molecules”.
I have no problem with the mechanism, and neither G&T nor Bohren do either. What they object to is the simplification of a very complex subject. As you say, to get things done, it is sometimes necessary to use the rule of thumb method. If you try to design an electronic amplifier, you can use the classic model of the transistor, which is infinitely complex. That’s because output circuits affect input circuits and vice versa, and the direct current operation differs markedly from the alternating current operation. If you just want a working amplifier, you can use the ROT approach, making certain resistor a certain amount larger than others, depending on the application and desired gain.
It seems to me that’s what has been done in climate science, particularly with modeling. I see the latter as more of a black art than a science and I think they have taken a few wrong turns. It’s one thing to study CO2 in a lab environment and quite another to extrapolate those findings to the atmosphere. One thing I’ve learned in my many years in the electrical/electronics/computer environment, is to compare an outcome to what makes sense. Sometimes you make a calculation and realize it makes no sense, because you’ve seen the circuit operate and the figures are wrong. In the same way, when I look at the rarity of CO2/ACO2 in the atmosphere, I get the feeling that something was missed.
As you say, the satellites are ringing warning bells and many people who should know better are simply not listening.
SJT “Clausius was talking about a closed system. The earth is being heated by an external energy source. The surface is not being made “hotter” than it orgininally was, it is just cooling down more slowly than it otherwise would have, given that it is being continually heated”.
That’s a decent argument but it fails to account for the increased WV that is expected from a warmer surface. That’s where your positive feedback is, in the increasing WV theorized for an increase in ACO2 that is supposed to warm the surface more.
Maybe you could explain the hotspot as you see it. I haven’t given the theory a lot of time, but my understanding is that the atmosphere was expected to warm beyond the surface temperature in the troposhere. That’s why John Christy approached a modeler with his satellite data, he thought the guy would be interested in the fact that he’d detected no tropospheric warming. Silly him. The modeler told him that his model was right and John’s satellite data was wrong.
SJT said…. “No point complaining about it, or those who study it. That’s just the way it is. If all we do is wait to see what happens, then it will be too late to do anything if it turns out to be the predicted disaster. We do have the models, and, as imperfect as they may be, they are our only guide to what is likely going to happen. Once again, no point blaming the scientists for that, that’s just how things are.”
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Nope…. Not so fast mate. There you go with that precautionary principle guff again…. As a fisherman I’ll give you an analogy to point out the stupidity of such a principle, so that you might understand it better.
You are on a boat……. You go down into the engine room and you see that there is water in the bottom of the boat…..!!! You immediately assume the boat is sinking and as a precaution. You abandon ship…..
However as a landlubber, you never realized that all boats have some water in them and that there are allowances for that… even a word for it….. Bilge water.
Now the hypothesis of AGW is just like that Bilge water…… and yes. It does stink 😉
Nick Stokes
“Globally, we use about 3kw per person ”
Unless I’m wrong, we have an installed generating capacity of ~180terawatts and a population of ~ 6 billion people.
That should give only 300 watts/person
Nick, I don’t mind helping boost your fragile self-esteem. However, I never claimed to have an expert witness contribution to the physics of this conversation. I am here as a student and as a representative of many others in the audience.
Do we note that you declined to elaborate on your UHI observations?
Nick said:
Marcus,
That’s just electricity, and indeed output electricity – the energy used to generate it is much higher. although mostly dissipated outside cities.
According to EIA figures, if I’ve converted BTU right, Australia consumes about 9 kW per person.
Nick Stokes “You yourself quoted Thevenin’s theorem a few days ago”.
I’ll back up what Jan is saying, that voltage drives current, not the other way around.
You have to to be careful with Thevenin because it is aimed solely at circuit analysis. It is one of about a dozen methods of analyzing circuits. Circuits are usually analyzed using mesh and node theory, with the nodes being circuit junctions where current converge and diverge, and the mesh refering to the circuit legs where the resistors, etc. are found. One of the most basic analysis tools is Kircheoffs Law, which address both. His node theory states that the sum of the currents entering a node must = 0 and his mesh theorem states that the sum of the voltage drops around a circuit must be 0, or that the sum of the voltage drops around a circuit must equal the applied voltage..
Thevenin is convenient when you want to replace parts of a circuit with an equivalent voltage. It’s only for convenience, however, and does not apply to a real life circuit. For example, if I have a microphone input to a pre-amplifier, on a drawing, I can replace it with an equivalent voltage source, which it is, and a resistor to represent its internal resistance. You can do the same thing with transformers, motors, or whatever you like.
Thevenin has nothing to do with a constant a current source, which is a convenient model only. It suggests that current can be injected into a circuit node as if the injected charges were peas in a pea shooter (whatever happened to pea shooters?). An electric current is actually a movement of electrical charges around a circuit and those charges will only flow if a voltage is applied. The voltage is the driving force behind a current.
In certain situations, it is desirable (by some) to think of parts of a circuit as being a constant current source, so they draw a circle with an arrow in it to represent that. A use for that is found in operational amplifiers, for example, but the actual circuit represented by the circle and arrow is actually a voltage source configured with feedback loops to keep the current constant. In other words, don’t walk into your local electronics supplier and ask for a constant-current source. It’s like asking for a bucket of steam.
There are power supplies on which you can limit the current, by dialing it up, or you can buy a power amplifier with current limiting on it. There again, they are actually voltage sources that sense the output voltage and cut or enhance the current to keep it constant. If a short circuit is detected, like a shorted speaker, the circuitry will clamp the current down to nothing. Removing the input voltage at any time will kill the output current, constant-current source or not.
The models are the realisation of the theory.
The historical analysis is a problem in that the Anthropogenic part of climate has only been around, in geological terms, for the blink of an eye. What we are doing has never been done before. This is groundbreaking stuff. There is some work on some examples of CO2 leading climate change, but it is a relatively rare event.
The evidence for warming is out there, now. Don’t forget, we are just at the start of the major changes, and, from the changes in the Arctic, we could just as easily be underestimating as over estimating.
I’ll make sure I listen to the experts, then. Hang, that’s just what I have been doing.
STJ that should read:
The models are (we assume) the realisation of the theory.
The historical analysis is a problem (we assume) in that the Anthropogenic part of climate has only been around, in geological terms, for the blink of an eye. What we are doing has never been done before. This is (we assume) groundbreaking stuff. There is some work on some examples of CO2 leading climate change, but it is a relatively rare event (we assume.)
The evidence for warming is out there, now (we assume). Don’t forget, we are just at the start of the major changes (we assume), and, from the changes in the Arctic, we could just as easily be underestimating as over estimating (we asssume.)
I only bring this up because STJ declared:
There is “no assumption” in the IPCC temperature rise claims are based on strong net positive feedback in our climate system. It’s all based on research.
(April 3rd, 2009 at 11:55 am)
Stj is a good boy: “I’ll make sure I listen to the experts, then. Hang, that’s just what I have been doing.”
Or as Gavin wisely advised: “There is no point in anyone reading what experts have written if they are not going to “go with the flow.” (April 3rd, 2009 at 6:44 am)
Comment from: wes george April 4th, 2009 at 7:48 pm
Nick, I don’t mind helping boost your fragile self-esteem. However, I never claimed to have an expert witness contribution to the physics of this conversation.
Comment from: wes george April 4th, 2009 at 11:38 am
STJ, you’re being disingenuous. Michael dispatched Nick’s objection within the hour:
Never??
Gordon,
(Near) constant current sources are real. Try drinking from a tap (and stopping the flow with your mouth). Or stand in the path of lightning.
And you can create a practical one. You can run a 60W light from a 240V mains source, which is close to a voltage source, It draws about 1/4 amp. Effective resistance 960 ohms. Or you can run it from a constant current source. From a 132 kV power line with a 528 kilohm resistor in series (don’t try this at home). It also draws 1/4 amp, and has a rms 240 V across it.
Then replace it with a 100W globe. It still draws 1/4 amp.
Gosh, I’m sorry Nick, I’ll be more careful with your ego from now on! Promise.
I have no idea why my post was ignored, was it too long, is this blog moderated?
I think Michael Hammer is wrong, you can’t use a winter summer type of temperature difference, which is meteorologic data, to the climate sensitivity factor as mentioned in IPCC AR4. The climate is still a long average of the meteorology, typically we talk about 20 to 30 year running averages.
Comment from: Jan Pompe April 4th, 2009 at 3:17 pm
Pompe wrote
[Eric
In the case of the electrical analog where one has a constant current source, one needs only to increase the resistance and the voltage will increase.
Sorry Eric you show yet again that you don’t understand it current does not drive the voltage. What on earth do yo think drives that current on a constant current source? The voltage can on increase to the source voltage when the current source is looking into an open circuit.
Like wise temperature drives heat flux not vice versa.
The problem with you is that your brain seems capable of comprehending electronics somewhat, but seems at a loss in comprehension of climate. In your desire to deny AGW, your emotions have taken over your reasoning capability.
In the case of the earth, the analog of current, the energy flux from the sun, is the driver. This is the analog of a constant current source. In the case of the heating of the house, you have a source of heat from the furnace.
Nick
That’s OK in order to be avoid being accused of being untruthful I’ve stopped telling people that you are a mathematician. 😛
For current sources Norton’s theorem is better but never mind that you are probably not even aware it exists.
A real DC power source IS voltage source with an internal resistance hopefully on with low resistance, zero resistance being ideal. A current source is better represented by a a current source with a large shunt resistance, open circuit being ideal (Nortons theorem). It’s the whole point behind the analysis I wrote up here:
http://www.esnips.com/doc/1d10d862-46c8-4789-b38f-57110caac249/PassiveFeedback
in section 5 and despite the shape of the graph it has nothing to do with singular perturbation. Now let’s separate the professional from the high school teacher and the amateur. Trouble with both theorems is that to those who don’t actually work with them it looks like the Norton current source can supply the fixed current regardless of the voltage of the source or the load same goes for the Thevenin’s voltage and current.
The reality is that if any impedance in the network or load is changed is changed Norton’s equivalent shunt resistance and current must both be recalculated similarly for Thevenin’s if anything is changed the Thevenised series resistance and voltage must be recalculated. What is the point of it then?
See http://www.esnips.com/doc/a1735013-5fd6-440e-acf2-8aa0ea66aa99/PassiveFeedback
It simplifies the calculations like in Section 5 I discuss maximising power to the load. I have only shown a simple system and only done it for a voltage source but if there is a complex network of impedance to deal with then thevenising or nortonising becomes an essential step. With heat transport in the planetary system just from surface to high troposphere to space there is conduction/convection, latent heat and radiation each with different laws so we are dealing with a complex system with different impedances, so something of the order of Thevenin/Norton theorem would perhaps simplify the process.
I think it’s worth a try.
Comment from: wes george April 4th, 2009 at 2:30 pm
Oh, I’m sorry Eric, I didn’t really understand that the factual errors and unsupported claim of it’s-illogical-because-I-said-so was all you had to regale us with.
Does this mean that’s it. You’re done? I’m disappointed. You sounded so well informed.
Once again you declare victory in a debate without having participated.
I pointed out two errors.
1) Your assignment of the “Hockey Stick” in a key role in the development of global warming,
2) Your false claim that the “stability” of the earth’s climate cannot be reconciled with the predictions of AGW, by those who support AGW.
At the time you wrote that post, you didn’t reply to either of those objections. I haven’t gone beyond page 23, but I suspect you have assumed that an empty unsupported sarcastic remark is all you have to offer in support of your thesis now.
Eric
Sorry in electric systems without an EMF potential difference there is no current likewise with thermodynamics if there is no temperature difference there is no heat flux ( though you might see heat fluxes but the net is zero).
It there is no current there is no work being done likewise in thermodynamics if there is no heat flux there is no work being done (that includes heating).
Gordon
Indeed the only use that I have found for it is
optimising the loadoptimising the source for the load I have had to drive.I used to use SPICE a lot that used Kirchhoff’s circuit analysis presently I trying qucs which uses S-parameters which I’ve mostly forgotten but am relearning. It’s looking good I’ve just been passing Leif Svalgaard’s TSI series through a low pass filter simulation with (not so) surprising results. Watch this space;-)
Comment from: Michael Hammer April 4th, 2009 at 4:11 pm
Eric to take your points first. You state that the models do not predict a “tipping point”. In what I write I am not specifically targetting models. There are many of these and I freely admit I do not know what every one of these predict. Rather I am commenting about the presentation of AGW to the public and the politicians, dominated by the pronouncements of the principle AGW advocates. Now I don’t think you can deny that James Hansen and Al Gore are the two most prominent AGW advocates and in fact I would claim that to the public they are the de facto voice of the AGW movement. Nor is Hansen just a spruiker he is after all the controller of the climate data that IPCC relies on (I cofess I wold have liked to say controller and manipulator but I am sure you would strongly disagree with the second descriptor). In the last two weeks I have read articles wherein Hansen claimed the planet is very close to a tipping point leading to irreversible climate change. If the models don’t predict such a tipping point, where is Hansen getting his information from. If the claim is unfounded it is not just an exaggeration, it is a significantly different and far more serious assertion. If Hansen’s comments are justified then my article stands in opposition. If Hansen’s claims are unfounded then I think it is time the AGW movement controls Hansen and ensured that what is claimed is substantiable, because the movement is being judged and evaluated by what Hansen and Gore claim.
It seems that you are backing away from your claim that AGW theory is in conflict with the daily changes of temperature that you observe in a certain part of Australia. You are trying to revise the record, and saying your comment was aimed against alarmists, Hansen and Gore.
It is no longer about the daily temperature in a certain region of Australia, but about the alarmism. Now you are saying that the AGW “movement” should control what Hansen and Gore are saying. Now it is not about science any more but about politics. Hansen is justly a famous scientist with a distinguished career, who was a pioneer in the modeling of climate. He has won prestigious awards for his work, including the Rossby prize from the American Meteorological Society, or something by that name. It is not in the power of anybody to shut him up, nor should anyone wish to. The man is smart and hard working. He could be right.
By the way, there may be some who throw invective around and make claims like the one you referred to in the thrid paragraph of your post. I try hard not to do so and I would like to state for the record that I do not support such actions. If someone thinks I have, I apologise. I believe this subject can only be resolved by serious and wide ranging debate which is what I am trying to foment and I thank you for your interest.
Now moving further. Could the sideways and upwards dispersal of the extra energy prevent the siuation I have been suggesting. The correct solution would be to cary out a mathematical analysis but the the reality is that this would be so complex few people active here would be able to understand it (probably including me). Next best, can we get some sort of quick “engineering approximation” which gives us some idea. I think maybe we can. There is another situation where a local region is heated differentially compared to its surroundings, one very prominently discussed in relation to AGW. It is the urban heat island effect – a city is heated by the extra energy emitted and by the presence on large amounts of masonary and absence of trees. Now we can easily see the urban heat island does exist, simply compare the temperature as reported each evening for the city centre compared with outlying suburbs. City centres are hotter. I have seen reports suggesting for example that Tokyo centre is 7 degres hotter than the outlying areas and something similar for New York. Melbourne where I live looks like it is 2-3 degrees hotter. Now is this not an example of a region which is receiving extra energy locally and that effect is showing up in higher local temperatures. Why is that any different from the scenario I describe? They are both local, probably over about the same region and the time scales are similar. Proof? no, strong suggestion? I think so. Nor is the impact of the additional water trivial. Consider, the humidity in an arid region could well be around 20% while in MacKay it could easily get to 80%. Thats 4 times the amount of water vapour at the same temperature or two doublings. Someone in this thread suggested 15 watts/sqM per doubling for water vapour. If so that would be an additional energy input of 30 watts/sqM – far from trivial.
The subject of climate has a history of being intractible and difficult to model. That is way there are 22 models, used and statistical ensembles of runs are being used to make the projections.
Now you say that for the sake of the people who wouldn’t understand a model, and engineering assessment will do, and besides YOU do not have access to a model.
I say so what. There are people who do have access to the models. They have run them and have explained what the results are. Why not use that. You admit they are better than an “engineering assessment” by a non climatologist.
Then you launch into a discussion of the quantification of energy flux and water vapor involved in the urban heat island effect, which seems like a stream of consciousness, with unsupported estimates taken out of the air, with no point or punch line. What is the thesis here? I see none.
Comment from: Gordon Robertson April 4th, 2009 at 4:41 pm
Eric Adler “If one constructs a thermal analog of an electrical circuit, current in amps is analagous to energy flux in watts. The thermal analog of Voltage is temperature. Voltage can be increased without an special power supply to amplify the signal”.
“If one constructs a thermal analog of an electrical circuit, current in amps is analagous to energy flux in watts. The thermal analog of Voltage is temperature. Voltage can be increased without an special power supply to amplify the signal”.
I don’t mean any disrespect, but your analogies leave a lot to be desired. If you’re constructing a thermal analog, you’d need atoms in substances at two different energy levels. Those energy levels would be equivalent to voltage levels and the current between those levels would be analogous to heat flow. The medium between the energies, like air in the atmosphere, would be resistance.
I don’t need anything of the sort because you say so it. The analogy is good for a macroscopic description of what is going on. It is just a device used to explain the flow of heat e to people who may have a grasp of electricity, and give them a useful conceptual picture of the heat flow equations.
The unfortunate part of analogies is people like yourself, and Jan Pompe, who don’t have an appreciation of the real science will misuse them. You are claiming that the microscopic theory of how the impedance is calculated is an important part of the analogy in this case.
You’re making it sound as though voltage is dependent on current, which is not the case. It’s true that a current running through a resistance creates a voltage drop across the resistance but that current was initiated in the first place by a voltage. When you talk about constant current sources, you have to be careful because they are theoretical devices that imply current can be injected into a circuit without a driving voltage. That’s not true. The constant current source is created using feedback control but the current itself comes from a voltage source, like a battery or a generator.
Don’t forget that current is a flow of charges, which is essentially a flow of electrons, which are the only carriers in a copper-wired circuit. Those electrons won’t move unless there is an electric field to drive them, and such an electric field is a voltage source. So, when you talk about voltages rising due to a constant current source flowing through a variable resistor, you are not talking about the same thing as a voltage from a power supply driving an electronic amplifier. The current from the constant current source came from a power supply. There is no such thing as an independent current source.
In an amplifier, amplification, or gain, is totally dependent on the power supply. A transistor operates by varying a larger current between it’s emitter and collector (its output circuit in a conventional common-emitter amplifier) in response to a smaller signal between its base and emitter. The larger current is supplied by the power supply, and that’s why you don’t get something like amplification for nothing.
Sorry but your grasp of the analogy is flawed. The analog of a current source is really driving the earth’s climate – the flux of radiation from the sun.
The amplification is dependent on doping in the transistor’s silicon, semi-conductor structure, where carriers (electrons in an NPN transistor) are seeded based on the desired amplification. However, the amplification in the transistor is merely a means of transfering control from the input to the output circuit in such a ratio that the output circuit is carrying a higher current based on the smaller input current. The output current has to be supplied from an external source since that larger current is not produced within the transistor..
It’s not necessary to understand the physics involved if you accept that a transistor is essential a variable impedance (resistance) that is controlled by a small input signal. The impedance is connected across the power supply (voltage) with the load between the transitor collector and the power supply. As the transistor changes impedance due to the input signal, it varies the voltage drop across it and that affects the attached load. In the case of a digital circuit, the transistor simply turns on and off rather than varying.
It is critical that the power supply voltage remains constant. Modern amplifier power supplies are regulated to a fraction of a percent. The voltage is rock solid. Any transistor circuit is an amplifier of some kind, even if the gain is less that 1 (unity). It cannot operate without a constant-voltage power supply. In audio or control circuits, where feedback is employed, the output current comes from the power supply. Without that constant voltage, the circuits would not work, or they would be unstable in the case of a varying power supply.
That’s why I am questioning the notion of CO2 being able to provide a positive feedback that increases the surface temperature. Where is the gain coming from? Some people claim it comes from the solar radiation but that makes little sense to me. When the surface radiates IR to the CO2, that represents a loss of energy on the surface. That lost energy is later back-radiated in part, because there are losses in the atmosphere. That already represents a negative feedback. The back-radiated energy is doing nothing more than replacing a portion of the energy it got from the surface, which got it from the Sun.
You can’t prove a theory wrong or right by using an analogy. An analogy is only correct in so far is it describes the actual situation. It is only an aid to the understanding of what happens in the system, after a valid theory has been developed, and it is determined that the analogy is useful for understanding the system. You can’t prove anything about the original system by arguing in detail about what happens in the analogy you have created to explain it. That is not how science works.
People who are ignorant about a science are susceptible to being persuaded that they understand it by being given an analogy, and will be unable to recognize an analogy as false.
This seems to be the case in the electronic analogy the Jan Pompe has set up. Because they are so comfortable about their understanding of the analogy, they don’t perceive that their understanding of the real science is flawed.
Jan
this is the same thing that happened with Arthur Smith. A descent into incoherent ramblings, then a claim of victory. You didn’t prove Smith wrong either, he just realised it is impossible to have a rational debate with you. If you can argue for hours on why G&T are correct, or Miscolczi is, there is no hope for a rational resolution of the issue. It just ends up in a pissing contest.
No, I was right, you are wrong.
Eric
The utility of the electrical analogy is the simplicity to understand without the complication of multiple transport laws to deal with. For the three main systems electrodynamic, thermodynamic and hyrodynamic varying resistance, insulation and occlusion respectively have similar, congruent effects on voltage/current, temperature/heat flux, pressure/fluid flow respectively if it weren’t so digital and analogue coputers would have great difficulty modelling them. If you can’t get your head around fact that potential difference drives electric current, temperature difference drives heat flux and pressure difference drives fluid flow then you really do not have a good understanding of any of it.
SJT
I have noticed that you tend to refer to matters beyond your comprehension as gibberish and incoherent ramblings.
It’s high time you got your head down and tail up and do some study – real study.
Comment from: Jan Pompe April 4th, 2009 at 9:52 pm
Jan Pompe wrote:
Eric
“In the case of the earth, the analog of current, the energy flux from the sun, is the driver.”
Sorry in electric systems without an EMF potential difference there is no current likewise with thermodynamics if there is no temperature difference there is no heat flux ( though you might see heat fluxes but the net is zero).
It there is no current there is no work being done likewise in thermodynamics if there is no heat flux there is no work being done (that includes heating).
I am not a fan of the use of analogies to explain things. One needs to have knowledge of two systems instead of one to assure that the analogies are correct. This is a strain on the thought processes. It seems that you are not up to it.
I will try to explain it to you. The sun’s energy flux is indeed the analogy for a current source. The temperature of the sun is extremely high. This is analogous to a very high voltage voltage source, and the impedance of space to the transmission of solar radiation headed towards earth is negligible.
Eric
I’m sure you are not which is probably why you don’t understand these things a well as you think you do.
Well yes but that is unavoidable especially in the area of electronic process control one needs to understand the process as well as the control system not to mention the transducers and how they work.
Furthermore models are all analogous to the systems the describe this is true if one is using analogue computers or digital computers.
No kidding!!! LMAO! That is precisely what I have been trying to tell you. There remains one bit of evidence that really don’t understand the system or your analogy that you gave with your high school experiment and your constant current source and I’ve high lighted in the quote.
A constant current source is a high impedance source not a low impedance one as you are now saying the solar heat source is. Now calculate the the radiation flux at the surface of the sun and that available at earth’s surface and then tell if you still think think it’s a low impedance source.
Fact of the matter is that you don’t seem understand either system very well.
My last post is a lesson in the perils of constructing an analogy.
Clearly the solar energy flux is the analog of an ideal current source. Nothing can stop the nearly constant solar radiation from being emitted by the sun and impinging on the earth atmosphere system.
The temperature of the sun, which is the analog of its internal voltage is very high.
The negligible impedance of space I mentioned in my last post does not complete the story, because if we are going to persue this analogy, an infinite impedance must exist inside the sun to make the high voltage, into a current source. I can’t think of what this is, and actually I don’t see why we should care.
We know the energy flux from the sun is what is driving the climate of the earth.
There is no point in pursuing the analogy any further than we have to. Circuits are circuits and the earth atmosphere system is what it is. Pursuit of an analogy further than necessary is only going to be a source of confusion.
Jan Pompe,
Eric said
” The sun’s energy flux is indeed the analogy for a current source. The temperature of the sun is extremely high. This is analogous to a very high voltage voltage source, and the impedance of space to the transmission of solar radiation headed towards earth is negligible.”
No kidding!!! LMAO! That is precisely what I have been trying to tell you. There remains one bit of evidence that really don’t understand the system or your analogy that you gave with your high school experiment and your constant current source and I’ve high lighted in the quote.
A constant current source is a high impedance source not a low impedance one as you are now saying the solar heat source is. Now calculate the the radiation flux at the surface of the sun and that available at earth’s surface and then tell if you still think think it’s a low impedance source.
Our posts crossed. I realized my mistake soon after I wrote the comment.
Since you are the person pursuing a circuit analogy you are the responsible for identifying the elements of the earth atmosphere system as circuit elements, and justifying the wiring and circuit elements that you choose, taking care that their properties mirror one another. Be sure you have ocean, atmosphere, sun, clouds, and proper treatment of radiation flux and absorption
and emission of different spectral fractions of the radiation travelling in various directions included. When you have done this, maybe you could write a paper on it. Good luck to you.
I pointed you to the simple excercise designed for high school or college students, which would be the standard way to illustrate a simple problem. The equations seem to work the way they should. The analogy of heating a house has validity in providing a basic understanding of the way the solar heating of the earths surface and the greenhouse effect of the atmosphere operate. I don’t know if this can or should be extended further. I personally don’t find it useful.
I am sure that the scientists who work on this do not use any analogies to do their work. They are perfectly comfortable with the science of heat, spectroscopy, thermodynamics and radiation and are using it to explain the phenomena that are taking place. In my reading of climate literature, I haven’t seen any reference to electrical analogies of earth atmosphere systems in any detail. Since you seem so interested in this you are more likely to have found something than I. Do you have a link or reference you could give us?
Eric Adler,
Simple hypotheticals:
A.We double CO2 this results in a warming of 1C and an increase of WV of 7%
Then we suck the CO2 out of the atmosphere to its regular level
Does the WV and temp return to its original level? IF not, what happens to them?
B. The sun heats up for the next month raises the temperature globally by 1C and increases the WV by 7%?
Then the sun returns to its regular level of output.
What happens to the WV and temp?
Now, whether or not I am correct in considering the increases in A & B as “forcings”, can we agree that the level of WV is dependent on those changes? If one of those changes was reduced to a “negligible” level, wouldn’t it also reduce the WV correspondingly?
And, for the record, I believe that it is possible to have a radiative forcing and for the Earth to be @ radiative equilibrium. That is the sort of equilibrium that I was talking about. I don’t know what sort of equilibrium you are talking about(in your April 4th 11:09 post). (I asked this before but you ignored it).
Comment from: Shawn H April 5th, 2009 at 2:07 am
Eric Adler,
Simple hypotheticals:
A.We double CO2 this results in a warming of 1C and an increase of WV of 7%
Then we suck the CO2 out of the atmosphere to its regular level
Does the WV and temp return to its original level? IF not, what happens to them?
B. The sun heats up for the next month raises the temperature globally by 1C and increases the WV by 7%?
Then the sun returns to its regular level of output.
What happens to the WV and temp?
Now, whether or not I am correct in considering the increases in A & B as “forcings”, can we agree that the level of WV is dependent on those changes? If one of those changes was reduced to a “negligible” level, wouldn’t it also reduce the WV correspondingly?
The avg. WV concentration would follow temperature, according to the data I have seen reported.
http://geotest.tamu.edu/userfiles/216/Dessler2008b.pdf
Between 2003 and 2008, the global-average surface
temperature of the Earth varied by 0.6C. We analyze here
the response of tropospheric water vapor to these variations.
Height-resolved measurements of specific humidity (q) and
relative humidity (RH) are obtained from NASA’s satelliteborne
Atmospheric Infrared Sounder (AIRS). Over most of
the troposphere, q increased with increasing global-average
surface temperature, although some regions showed the
opposite response. RH increased in some regions and
decreased in others, with the global average remaining
nearly constant at most altitudes. The water-vapor feedback
implied by these observations is strongly positive, with an
average magnitude of lq = 2.04 W/m2/K, similar to that
simulated by climate models. The magnitude is similar to
that obtained if the atmosphere maintained constant RH
everywhere.
And, for the record, I believe that it is possible to have a radiative forcing and for the Earth to be @ radiative equilibrium. That is the sort of equilibrium that I was talking about. I don’t know what sort of equilibrium you are talking about(in your April 4th 11:09 post). (I asked this before but you ignored it).
I am talking about radiative equilibrium – incoming radiation equals radiation to outer space
(neglecting the small amount of energy flow coming from the interior of the earth)
When there is radiative equilibrium averaged over long periods of time, there is no systematic average surface temperature change, only statitistical fluctuations.
Radiative forcing has been designed to measure the changes in radiation balance that have occurred since 1750, according to the IPCC definition.
As I understand it, radiative forcing and climate sensitivity determine the temperature change that will take place in the future if the conditions that have created the radiative forcing continue.
http://en.wikipedia.org/wiki/Radiative_forcing
Radiative forcing can be used to estimate a subsequent change in equilibrium surface temperature ΔTs change arising from that radiative forcing via the equation:
ΔTs =λ * ΔF,
where λ is the climate sensitivity, usually with units in K/(W/m2), and ΔF is the radiative forcing.
I believe the above equation implies that when ΔF=0 that we have equilibrium and the temperature (long term global average) will not change. If ΔF is not zero, the temperature will change, and we don’t have thermal equilibrium.
So Nick Stokes, 50watts/M^2 will unsurprisingly cause a UHI of a few degrees. The effect of doubling CO2 is how many watts/M^2 ?
The crux of this feedback issue is that for the AGW mantra to be correct and for eric, nick and the rest to be not yodelling in the hills is that water has to be increasing; Weaver and Ramanathan sum it up in their cocluding remarks;
“For example, with an increase in surface temperature, if the water vapor content increases, the width of the window decreases and leads to a positive feedback.”
http://envsci.rutgers.edu/~weaver/Pubs/weaver_ramamathan95.pdf
eric has linked to Dessler, who at the level of causality, is rebutted by Roy Spencer;
http://www.drroyspencer.com/2009/02/what-about-the-clouds-andy/
But the fundamental problem with the positive feedback from water is whether water is increasing;
http://www.friendsofscience.org/assets/documents/FOS%20Essay/GlobalRelativeHumdity22/12/2008300_700.jpg
http://wattsupwiththat.com/2008/06/21/a-window-on-water-vapor-and-planetary-temperature-part-2/
Sorry, that link to RH is here;
http://www.friendsofscience.org/assets/documents/FOS%20Essay/GlobalRelativeHumidity300_700mb.jpg
The point is both SH and RH are falling and in the case of SH increasing only at near surface levels consistent with Miskolczi so that OD is maintained; Dessler’s model shenanigans doesn’t change that; and it also doesn’t deal with Spencer’s thesis that even if there were an increase in water that negative feedback would not occur.
Eric
LMAO What on earth do you think computer models are?
“Do you have a link or reference you could give us?”
http://www.esnips.com/doc/1d10d862-46c8-4789-b38f-57110caac249/PassiveFeedback
It won’t help you it’s graduate level control theory being applied the boxes you by the look of it haven’t reach 100 level yet.
The boxes are simply generalised gain “blocks”, not electrical analogues or models of the earth system, that I have used to show how the equation Eo = A/(1-AB) (you posted this remember not me) cannot and does not describe feedback in a dissipative system.
I go on to give an example of a simple electrical dissipative system the voltage divider and give the “feedback” equation for that
Vo = Rl/Rs(Vi – Vo) and lo and behind the feedback is negative go ahead expand and gather the voltage terms then solve for Vo then you’ll see the equation is correct. but one can readily see from the eqation given that if you hold Vi and Rs constant Vo will rise with rising Rl.
If you want an equation for the atmosphere then you need to take a look at the work of atmospheric physicist
http://miskolczi.webs.com/2007.pdf
Eqn 20 is the one
πB_o = H/2A(2/f – τ_A *A) – π*B_G*T_A/A
I have other things I must do but you can read the paper to get what the terms refer too but as you see from Figure 3 (the equation plotted) the effect of varying τ_A (the optical depth or impedance to transmission) has the same effect on power output as varying the load resistance in the voltage divider. The feedback is negative.
Comment from: Jan Pompe April 5th, 2009 at 8:35 am
Eric
“I am sure that the scientists who work on this do not use any analogies to do their work.
LMAO What on earth do you think computer models are?
“Do you have a link or reference you could give us?”
http://www.esnips.com/doc/1d10d862-46c8-4789-b38f-57110caac249/PassiveFeedback
It won’t help you it’s graduate level control theory being applied the boxes you by the look of it haven’t reach 100 level yet.
The boxes are simply generalised gain “blocks”, not electrical analogues or models of the earth system, that I have used to show how the equation Eo = A/(1-AB) (you posted this remember not me) cannot and does not describe feedback in a dissipative system.
I go on to give an example of a simple electrical dissipative system the voltage divider and give the “feedback” equation for that
Vo = Rl/Rs(Vi – Vo) and lo and behind the feedback is negative go ahead expand and gather the voltage terms then solve for Vo then you’ll see the equation is correct. but one can readily see from the eqation given that if you hold Vi and Rs constant Vo will rise with rising Rl.
Your reference is an article by you that is about electrical circuits. There is currently nothing in the chapter you have entitled “Atmosphere”. From the title and the date, you have just begun to write this article today. This is not research on the atmosphere.
If you want an equation for the atmosphere then you need to tak
e a look at the work of atmospheric physicist
http://miskolczi.webs.com/2007.pdf
Eqn 20 is the one
πB_o = H/2A(2/f – τ_A *A) – π*B_G*T_A/A
I have other things I must do but you can read the paper to get what the terms refer too but as you see from Figure 3 (the equation plotted) the effect of varying τ_A (the optical depth or impedance to transmission) has the same effect on power output as varying the load resistance in the voltage divider. The feedback is negative.
I did not ask for equations. There are people working on atmospheric physics who believe that there is negative feedback in the system. Miskolczi is obviously one of them. He is what one would call an outlier, but that is neither here nor there.
You have not, and will not find an atmospheric physicist who uses a detailed electrical circuit analog as a model for the earth atmosphere system to do his/her work. Any equations that are developed come from the theory of radiation, fluid dynamics, thermodynamics etc.
If equations are similar, it is a result of coincidence, not of physical principles.
“I have noticed that you tend to refer to matters beyond your comprehension as gibberish and incoherent ramblings.
It’s high time you got your head down and tail up and do some study – real study.”
No, I know my limitations, but I also know how to spot gibberish. Exhibit A, your debate with Arthur Smith. Exhibit B, your debate here. G&T is a prime example of gibberish dressed up as science.
Will your exhibits just make my point that you really don’t know your limitations.
Comment from: cohenite April 5th, 2009 at 8:35 am
Sorry, that link to RH is here;
http://www.friendsofscience.org/assets/documents/FOS%20Essay/GlobalRelativeHumidity300_700mb.jpg
The point is both SH and RH are falling and in the case of SH increasing only at near surface levels consistent with Miskolczi so that OD is maintained; Dessler’s model shenanigans doesn’t change that; and it also doesn’t deal with Spencer’s thesis that even if there were an increase in water that negative feedback would not occur.
The origin of the FOS data is not given. How was this obtained?
In addition, where is the corresponding temperature data so that we can determine whether there was a change in absolute WV concentration. For most of the altitudes the change in RH was modest since the mid 1970’s, the start of the GW period. It amounts to 1 to 2 %. For a .6C change, the WV concentration increases about 4% at constant RH, so this doesn’t constitute a decrease in the amount of WV in the atmosphere.
The RH data is here;
http://www.cdc.noaa.gov/cgi-bin/data/timeseries/timeseries.pl?ntype=1&var=Geopotential+Height&level=1000&lat1=0&lat2=0&lon1=0&lon2=0&iseas=0&mon1=0&mon2=0&iarea=0&typeout=1&Submit=Create+Timeseries
The SH levels are in the watts link; as well here is the relevant temperature data;
http://www.junkscience.com/MSU_Temps/UAHMSUglobe-m.html
Your estimate of the decline in RH is quaint;
http://www.friendsofscience.org/assets/documents/FOS%20Essay/GlobalRelativeHumidity300_700mb.jpg
I would say closer to 22% at the 300mbar level so RH has NOT been constant. The water readings have been verified by the Paltridge et al paper;
http://www.theclimatescam.se/wp-content/uploads/2009/03/paltridgearkingpook.pdf
There has been a real decline in water; there has been no meaningful increase in temperature; the only thing supporting AGW is the models and some esoteric theoretical arguments.
“I pointed you to the simple excercise designed for high school or college students, which would be the standard way to illustrate a simple problem. The equations seem to work the way they should. The analogy of heating a house has validity in providing a basic understanding of the way the solar heating of the earths surface and the greenhouse effect of the atmosphere operate. I don’t know if this can or should be extended further. I personally don’t find it useful.”
As they say on that meditation on the human condition, “Planet of the Apes”, “Don’t look for it, Taylor. You may not like what you find”.
You’re problem is you only modelling the earth in terms of electronic components, and a limited range at that. What you need is a hypothetical electronic component that absorbs some of the electrons passing through it, and then randomly emits some of them back where they came from, or forward with the rest of the current. The earth is a lot more complex than your simple models are capable of reproducing. If you used computer code, you wouldn’t have those limitations. You know, I think those modelers are way ahead of you on that count, and have already done just that.
Eric; IMO the subject of analogies is a cruel diversion because it only serves to highlight the difficulties of language and communication between individuals and I hope Wes picks up on this too.
Unfortunately I’ve been feeling too crook to participate and thinking about my own ‘terminal’ for most of the thread. Besides; I had to wait till yesterday to format my main desktop PC after an update for Adobe Reader downloaded from the web left some bug wandering round its operating system too.
This theme of mine about analogies has been piling up with every page
Nick: “Marcus, That’s just electricity”
Gordon: “nick, I’ll back up what Jan is saying, that voltage drives current, not the other way around”.
“Thevenin has nothing to do with a constant a current source, which is a convenient model only”
Jan has this very bad habit of dragging us down his own revision path. I for one am too old for it having returned to college about half a dozen times to keep up with advances in technology, each time doing the some revision of the applied math and circuit theory. What we never studied in class was the fact most advanced measurement and control systems still employ people like us. In the end I decided to step right back and look at the greatest potential for havoc in any process design and development then went silently (most of the time about) my business including career changes. Casual rather than formal recognition of standards and competence was another line of mine throughout any transition. Sure, have faith in knowing your peers well but properly handing over demands utmost trust in our next generation.
At a time when I still had a large collection of ‘passive’ hardware, the remnants of a deceased electronics business I purchased near Monash Uni in Melbourne, I built two versions of constant voltage or current sources (switchable) in Arlec power supply cases after reading articles on the merits in design of constant current sources in Electronics Australia. As both seemed to work OK they remained in my toolbox for years and even got hired to electrical engineers on odd occasions despite their crude assembly on hobby board, for testing say 4-20 ma or 0-50 V dc circuits over time. The concept of voltage follower etc theory is well established. No drift Jan!
Astute readers will find none of the above has anything to do with climate change. On Maccac’s Australia All over radio show today I heard a guy say “anyone visiting Canberra should bring their own bottle of water”
http://www.abc.net.au/australiaallover/
We had 10 cm in three months? The showers this weekend ran off, leaving a mess of debris piled around dried clumps of grass. Also I think our dear Jane Edmundson on Gardening Australia this weekend said the word “bugger” as she was digging a dry garden somewhere for her spot in the program.
http://www.abc.net.au/gardening/
I had a guy cut down more big trees this week and the view up close is somewhat less depressing. I don’t need to witness three or four decades of growth, dying beside our window nor do we need it seems all the wet happening up the coast. We go on despite some diehards digging in their math for excuses.
I decided a long time ago now that a ‘pure’ anything as a concept was just that, a structured private idea at best and like most models it has limited use in the real world. Attacking the model of say 9/11 after the event is of limited value too but that is ‘science’ at best. It may help our collective understanding by perhaps adding more jargon such as 9/11 but it won’t change the elements of disaster.
Every one must keep their eyes open and while doing that some analogies are useful.
Ah, but Gavin you have participated in this debate brilliantly. I doubt I shall ever forget this gem of pure insight into the soul of an AGW acolyte:
“There is no point in anyone reading what experts have written if they are not going to “go with the flow.”
(April 3rd, 2009 at 6:44 am)
Eric
No?
then read
“A simple expression for vertical convective fluxes in planetary
atmospheres ” By Lorenz and McKay 2002 and pay particular attention to Figure 4.
“http://cat.inist.fr/?aModele=afficheN&cpsidt=15174845”
I really can’t help that you don’t understand the equation that YOU introduced is lifted straight from Bode theory of feedback amplifiers.
MPw instead of pissing about with complaints about how physical systems might or might be modelled with analogue computers why don’t you show how the heat signal can spontaneously climb up the temperature gradient to provide the positive feedback.
The above seems to be Eric’s central argument.
Eric has the burden of proof ass backwards. M. Hammer doesn’t have to prove anything with his thought experiment. It’s merely a rational question put to a central tenet of the AGW orthodox hypothesis — is WV feedback is really positive on climate? The burden of proof lies with the AGW orthodoxy to convincingly answer the questions that arise from the hypothesis’s implications.
To ask hard question to a hypothesis is part of the process of scientific inquiry. Yet, when Eric denounces Michael Hammer as a “denialist,” he reveals that he believes to merely question the AGW hypothesis is analogous to a heretic challenging the orthodoxy — Eric’s intellectual gestalt is deeply inculcated with the sanctity of consensus approval over individuality and independent reasoning.
A scientist when confronted by a question does not feel threatened, but curious as to why it should be asked. Why can’t we directly observe strongly positive WV feedback on a local scale? Hmmm. Very curious, indeed. I wonder what is going on? Eric is not the least bit curious. I wonder why?
Scientists relish testing their hypothesis against all possible observations. Each time a hypothesis can explain a new observation it is strengthen. The burden of proof lies with the hypothesis itself and how it answers the questions put to it will either improve its usefulness or falsify it. A hypothesis is only as good as it predictions (implications). Rational explanation of curious phenomena is what animates the scientific spirit. Not so for defenders of dogma, historically those who ask questions have been meet with denunciation rather than curiosity.
This is the source of my discontent with incurious commenters who seem to have some grasp of the physics involved yet frame their argument with denunciations more appropriate of Copernicus’s age than to the fundamental logic of the dialectics of the modern scientific method.
How can one claim to be scientifically literate and not respect the fundamental rules of rational inquiry?
Eric’s comments illustrate a complete misunderstanding of how progressive science works. Hammer doesn’t need a GMC. Hammer’s thought experiment is nothing more than saying, “hang on a minute, I don’t see what the AGW hypothesis is predicting going on in the back garden, I wonder why?” Regardless of whether he is right or wrong, it’s fair dinkum science in that it is an inquiry into the implications of a hypothesis based on direct observation and the application of fundamental logic.
If I may sum up the logic behind Eric’s replies to M. Hammer:
1. The AGW hypothesis is correct because smart people say so
2. The computer model predictions based on AGW predictions, predict AGW is real
3. Those failing to be persuaded by 1 and 2 are “amateurs,” “incompetent” and/or “delusional”
4. It’s too hard for anyone but an elite priesthood to understand, so don’t try.
5. “You got no proof.” Let’s reverse the rules of who’s responsible for the burden of proof.
6. Direct observation, applied logic and a dollop of inspired intuition are trumped by 1, 2 and 4.
7. “Look there goes a possum” (as in digressions into non sequitur)
Adler’s defense of AGW amounts to an admission that he can’t rationally defend WV pos feedback at all. Of course, this doesn’t mean there isn’t one, it’s just it has not been rationally and cogently explained here by the AGW hypothesis’s acolytes.
The history of science is littered with the carcasses of grand orthodox theoretical constructions that came crashing down into a pile of quantitative rubble because a of clear headed outsider or amateur who asked a the right question to the right problem based on the simplest of observations and intuition.
(all quotes are Eric Adler)
Will
yes you can do anything with those even build a model perpetuum mobile with impunity.
Thanks for the papers luke; I’ll send the Nicholl’s paper to Stewart Franks; Dr Nicholls appears to contradict the recent conclusions of Dr Nerilie Abram [whose recent paper was reported in the April edition of Australasian Science, p25] that the cause of rainfall decline in the SE was due to the IOD.
Wes; on concensus, if I sent a dozen people outside with their household thermometers to do a reading at some point I would expect at least one to return with an exact measurement of the temperature and that could be verified by simply looking at the others.
On climate change, sea levels and even agw I could respect their views too without much addo.
Man; in thinking about living, its mostly using the tools we were given in the first place
“yes you can do anything with those even build a model perpetuum mobile with impunity.”
I take it you accept the rest of my claims then. Good.
As for the possibilities for models to wrong, they certainly did have positive feedback loops that went out of control and bugs. That’s why there are completely independent research centres building their own models, with entirely their own code, over many years of testing and development.
“Eric has the burden of proof ass backwards. M. Hammer doesn’t have to prove anything with his thought experiment. It’s merely a rational question put to a central tenet of the AGW orthodox hypothesis — is WV feedback is really positive on climate? The burden of proof lies with the AGW orthodoxy to convincingly answer the questions that arise from the hypothesis’s implications.”
They have provided reams of evidence, all the papers the IPCC report is based on. They are all listed and referenced. Michael has just said “What if?”. Not much to go on there.
SJt
You can’t see anything wrong with that?
It’s hardly surprising.
Of course take a number of runs of these models throw out the results you don’t like then take an average of the out put ant call that science.
Sorry will it doesn’t work like that.
I am continually amazed at how many mind readers we have here, who know what Climate scientists think, when IMHO, they have absolutely no idea. I would suggest the best thing they can do is try to arrange interviews the scientists themselves, rather than continually attacking strawmen and creating misrepresentations.
“Of course take a number of runs of these models throw out the results you don’t like then take an average of the out put ant call that science.
Sorry will it doesn’t work like that.”
Once again, you have no idea.
Will “Once again, you have no idea.”
Oh the dire warnings don’t come from a consensus of models and modellers?
Where does it come from then?
All I’ve seen in the empirical data is cyclic climatic behaviour and that we have recently passed a local (of perhaps a millennial scale bons cycle) peak so it cant be from there.
SJT:
“I am continually amazed at how many mind readers we have here, who know what Climate scientists think, when IMHO, they have absolutely no idea”.
Who? The climate scientists ? Hardly surprising and tyhis is the explicit meaning of your sentence.
Ah, the tragedy of a progressive education……
SJT:
“The models are the realisation of the theory.
The historical analysis is a problem in that the Anthropogenic part of climate has only been around, in geological terms, for the blink of an eye. What we are doing has never been done before. This is groundbreaking stuff. There is some work on some examples of CO2 leading climate change, but it is a relatively rare event.”
Based on what empirically measured or observed evidence?
SJT:
“There is some work on some examples of CO2 leading climate change, but it is a relatively rare event.”
Climate change is not a physical process but a human abstraction. Therefore CO2 cannot lead or trail it.
Huh ???
In your mindless haste to defend the “lines” you demonstrate quite clearly why this thread is 32 pages long and nobody has added anything new concerning MH’s question. I don’t have to be a “mind reader” to note that modelling WV will be by far the most difficult part of the exercise.
Since you seem to like appeals to authority so much I will re-submit my earlier post as you clearly didn’t read it. Instead of interviewing the scientists why don’t I let the IPCC do that and also let them summarize their findings for me ….
You said
Yet the scientists are already well aware of the limitations of their models, and that is why they are moving on to the next generation, which will be capable of handling clouds more realistically. No one has had to raise any questions on that matter, they already knew it. They relished the challenge years ago, and have long been planning how to deal with it. The new computers should be running soon.
Wes Wrote:
Comment from: wes george April 5th, 2009 at 12:30 pm
” Michael’s argument…can’t prove as such the model calculations are incorrect. (April 3rd at 11:29 am) M Hammer’s claim is that the positive feedback due to WV should be immediately discernible. We have to weigh his claim based on instinct, against the more detailed calculations of the scientists who research climate as their life’s work.”
The above seems to be Eric’s central argument.
Eric has the burden of proof ass backwards. M. Hammer doesn’t have to prove anything with his thought experiment. It’s merely a rational question put to a central tenet of the AGW orthodox hypothesis — is WV feedback is really positive on climate? The burden of proof lies with the AGW orthodoxy to convincingly answer the questions that arise from the hypothesis’s implications.
I don’t think this is backwards at all. The tool that Michael is using, simple observation of the climate at one or 2 locations are inadequate to the job of assessing what controls climate.
Even with powerful computers and satellite observations it is difficult to do the task that Michael claims to be able to do by watching the weather. It was pointed out that his argument did not take account of lateral motion of air, which is what Global Clmate models are designed to do.
As a matter of fact, as I mentioned in one my earliest posts on this thread, 2/3 of the observed increase in global average temperatures comes about as a result of increases in nighttime temperatures, which are when the greenhouse effect and the effect of WV would be most potent, according to Michael Hammer, himself.
” The fact that you persist in your denials of these accepted physical theories shows how the human mind can be deluded by a desire to believe what it wants and discard solid scientific theories.”
To ask hard question to a hypothesis is part of the process of scientific inquiry. Yet, when Eric denounces Michael Hammer as a “denialist,” he reveals that he believes to merely question the AGW hypothesis is analogous to a heretic challenging the orthodoxy — Eric’s intellectual gestalt is deeply inculcated with the sanctity of consensus approval over individuality and independent reasoning.
I don’t recall saying that about Michael Hammer. It is too many posts back for me to search and retrieve the context. Since you have moused this in your post, maybe you could clarify this by telling what page this quote came from.
In that sentence I was referring to people who claimed that the first law of thermodynamics was violated by positive feedback, and that the Greenhouse effect violated the second law of thermodynamics. Michael Hammer does not claim either of these.
A scientist when confronted by a question does not feel threatened, but curious as to why it should be asked. Why can’t we directly observe strongly positive WV feedback on a local scale? Hmmm. Very curious, indeed. I wonder what is going on? Eric is not the least bit curious. I wonder why?
I am not persuaded by Michael’s blog post that we cannot observe it on a local scale.
The down-welling radiation due to WV is easily observable, and in there is data showing that it increases with increasing WV concentration:
http://www.iap.unibe.ch/publications/download/2900/en/
There can be no argument that the rate of evaporation increases with temperature. QED, so in a clear air situation, there is no doubt that local feedback can be observed.
If one wants to include clouds in the picture that becomes complicated. There is no way to make a local observation from the ground to discern the net effect. Satellite observations of the entire globe, as well as ground observations are needed to discern the type of clouds and their reflective properties as well as the IR emissions from them.
Scientists relish testing their hypothesis against all possible observations. Each time a hypothesis can explain a new observation it is strengthen. The burden of proof lies with the hypothesis itself and how it answers the questions put to it will either improve its usefulness or falsify it. A hypothesis is only as good as it predictions (implications). Rational explanation of curious phenomena is what animates the scientific spirit. Not so for defenders of dogma, historically those who ask questions have been meet with denunciation rather than curiosity.
This is the source of my discontent with incurious commenters who seem to have some grasp of the physics involved yet frame their argument with denunciations more appropriate of Copernicus’s age than to the fundamental logic of the dialectics of the modern scientific method.
How can one claim to be scientifically literate and not respect the fundamental rules of rational inquiry?
I object to the idea that you are using the fundamental logic of the dialectics of modern scientific method. I am not against rational inquiry. I only object to ignorance, stupidity, the use of conspiracy theories and assumption that scientists, after decades of research , or actually 150 years of research on climate, don’t know what they are talking about, and half educated amateurs know better. The few real scientists that minimize AGW, reject many of the arguments presented by the amateurs here , such as the first and second laws of thermodynamics are violated by the greenhouse effect and WV feedback.
” If you are going to claim that other processes overwhelm the positive feedback provided by WV and the GHE, you will need to produce a General Circulation Model…April 3rd, 2009 at 7:48 am ”
Eric’s comments illustrate a complete misunderstanding of how progressive science works. Hammer doesn’t need a GMC. Hammer’s thought experiment is nothing more than saying, “hang on a minute, I don’t see what the AGW hypothesis is predicting going on in the back garden, I wonder why?” Regardless of whether he is right or wrong, it’s fair dinkum science in that it is an inquiry into the implications of a hypothesis based on direct observation and the application of fundamental logic.
I don’t know what you mean by progressive science. This is a term I have not heard before, and you haven’t defined it. The only way that climate science can make any progress is through more accurate computation and more accurate global observations. This is what I would call progressive science.
It is certainly valid to look out the window at the weather and on the basis of your observations ask questions about what could be happening, but the fact is that you won’t be able to obtain any good answers to your questions without doing what I call progressive science. The people who are doing what I call the progressive science are the ones who are going to find the answers. That is what I pointed out to Mr Hammer.
If I may sum up the logic behind Eric’s replies to M. Hammer:
1. The AGW hypothesis is correct because smart people say so
2. The computer model predictions based on AGW predictions, predict AGW is real
3. Those failing to be persuaded by 1 and 2 are “amateurs,” “incompetent” and/or “delusional”
4. It’s too hard for anyone but an elite priesthood to understand, so don’t try.
5. “You got no proof.” Let’s reverse the rules of who’s responsible for the burden of proof.
6. Direct observation, applied logic and a dollop of inspired intuition are trumped by 1, 2 and 4.
7. “Look there goes a possum” (as in digressions into non sequitur)
Adler’s defense of AGW amounts to an admission that he can’t rationally defend WV pos feedback at all. Of course, this doesn’t mean there isn’t one, it’s just it has not been rationally and cogently explained here by the AGW hypothesis’s acolytes.
Even if you are creating a straw man argument to knock down, it is progress for you.
Previously you simply declared victory in a debate without even participating.
This is a complex system, and instincts of an amateur in such a situation are likely to be wrong….beyond the comprehension of many of the readers and posters on this blog.
The history of science is littered with the carcasses of grand orthodox theoretical constructions that came crashing down into a pile of quantitative rubble because a of clear headed outsider or amateur who asked a the right question to the right problem based on the simplest of observations and intuition.
There is nothing clear headed about AGW denialism. It is not based on curiousity at all. Many of the arguments are a pile of rubbish which has been discredited. You can look at a number of web sites to see them debunked – for instance “Skeptical Science”.
There are many reasons why it hangs on.
1) People are reluctant to face a problem that will occur in the future if they have to make changes and give up something in the present.
2) The problem is not obvious. It requires complex computation to see it, and a grasp of ideas that are difficult and unfamiliar to explain.
3)It requires government action by the entire world, which runs against the ideology of many people.
There is uncertainty about the extent of AGW, which is certainly a valid thing to discuss
ie. where in the range of say 1.5 – 4.5C will CO2 doubling take us? How fast is the ice actually melting in Antarctica and Greenland etc. ?
Getting back to the subject of the merits of Michael Hammer’s questions, let’s examine this paragraph:
We know the earth rotates about an axis tilted about 23 degrees relative to the sun. This is what causes the seasons and what sets the Tropics of Cancer and Capricorn. Imagine a location on the Tropic of Capricorn (23 degrees south) – say Mackay in Queensland. In summer the sun is directly overhead – average solar input of around 310 watts/sq meter. In winter the sun is at maximum elevation 44 degrees – average solar input of around 220 watts/sq meter. That is a difference summer to winter of about 90 watts/sq meter which, according to Stefan’s law, without any feedbacks would give a temperature difference summer to winter of about 16 degrees. The amount of positive or amplifying feedback claimed by the IPCC would inflate that about 6 times to more than 90 degrees C, extinguishing all life in Mackay.
This may have been pointed out already and I may have missed it, but a theoretical winter to summer temperature difference, calculated on the basis of average solar radiation is not what real climate scientists claim is going to be amplified by positive climate feedback. These temperatures calculated from Stefan’s law are not real temperatures. Their values are winter 249.6K ( -23C) and summer 271K (-2C).
The quoted feedback is a number that emerges from a computer calculation of yearly average global temperature change on top of the average temperature calculated without forcing.
As was mentioned before many times, the feedback is not 6X but rather 3X.
This is a straw man argument pure and simple. I would not characterize it as “clear headed” or “progressive science. It is clearly junk science.
I forgot to add that the reason of course that one of the reasons not mentioned that Stefan Boltzmann equation does not give the real temperatures at Mackay is the Greenhouse Effect, which, as John Tyndall recognized 150 years ago, makes the earth warmer than it would otherwise be and keeps the night time temperature from falling. It turns out that most of the global average temperature increase in the past 30 years has come from increase in night time temperatures?
Oops, I am afraid I am repeating myself.
Comment from: Louis Hissink April 5th, 2009 at 9:27 pm
SJT:
“The models are the realisation of the theory.
The historical analysis is a problem in that the Anthropogenic part of climate has only been around, in geological terms, for the blink of an eye. What we are doing has never been done before. This is groundbreaking stuff. There is some work on some examples of CO2 leading climate change, but it is a relatively rare event.”
Based on what empirically measured or observed evidence?
http://www.sciencedaily.com/releases/2005/02/050223130549.htm
Eric, I don’t understand what you are going on about, but if you think that the avg. water vapor follows ave. temperature and ave temp follows the forcing, then we don’t disagree. It, follows, thusly, that if you reduce the forcing to a negligible level, you will also reduce the level of WV. That is what I have been saying from my very first post on this issue.
As to the issue with radiative equilibrium, I think your confusion arises from the fact that a higher level of forcing(delta F) will result in a higher equilibrium surface temperature by “forcing” a *new* radiative quilibrium to be reached. The atmosphere will have separate (different) radiative equilibria at different levels of forcing.
At a level of 0 forcing, all it means is that the surface temp will equilibriate at whatever is considered to be the original or baseline temperature.
To say that radiative equilibrium can only be achieved when delta F = 0 is inaccurate.
Eric said:
AND in the NH, especially the arctic. The tropics and the southern hemisphere are still the same temp they were 30 years ago.
http://www.climate4you.com/images/MSU%20UAH%
now don’t say it’s because most of the land is in the NH because we aren’t entirely landless down here so there must be some proportional increase if your theory is correct. Unfortunately there is no increase so it appears the theory is incorrect. One day some one will discover why the arctic is increasing in temp and the cause of the global temp increase.
Comment from: Shawn H April 6th, 2009 at 5:35 am
Eric, I don’t understand what you are going on about, but if you think that the avg. water vapor follows ave. temperature and ave temp follows the forcing, then we don’t disagree. It, follows, thusly, that if you reduce the forcing to a negligible level, you will also reduce the level of WV. That is what I have been saying from my very first post on this issue.
Good. I expect therefore, that you don’t believe the constant positive imbalance of energy flux into the earth atmosphere system is needed to maintain a higher WV concentration based on the first law of thermodynamics.
As to the issue with radiative equilibrium, I think your confusion arises from the fact that a higher level of forcing(delta F) will result in a higher equilibrium surface temperature by “forcing” a *new* radiative quilibrium to be reached. The atmosphere will have separate (different) radiative equilibria at different levels of forcing.
At a level of 0 forcing, all it means is that the surface temp will equilibriate at whatever is considered to be the original or baseline temperature.
To say that radiative equilibrium can only be achieved when delta F = 0 is inaccurate.
I guess you are right about that. Here an excerpt from an National Academy of Sciences paper
which defines the meaning of radiative forcing. It is defined with respect to an specific unperturbed state and determines the change in temperature relative to the unperturbed state when the final temperature has been reached.
http://www.nap.edu/openbook.php?record_id=11175&page=21
According to the radiative-convective equilibrium concept, the equation for determining global average surface temperature of the planet is
dH/dt=f-T’/ λ (1.1)
where H is the heat content, f is the forcing, T’ is the change in temperature in response to
Equation 1-1 describes the change in the heat content where f is the radiative forcing at the tropopause, T′ is the change in surface temperature in response to a change in heat content, and λ is the climate feedback parameter (Schneider and Dickinson, 1974), also known as the climate sensitivity parameter, which denotes the rate at which the climate system returns the added forcing to space as infrared radiation or as reflected solar radiation (by changes in clouds, ice and snow, etc.). In essence, λ accounts for how feedbacks modify the surface temperature response to the forcing. In principle, T′ should account for changes in the temperature of the surface and the troposphere, and since the lapse rate is assumed to be known or is assumed to be a function of surface temperature, T′ can be approximated by the surface temperature. For steady state, the solution yields
T’=f/ λ (1.3)
So at equilibrium when the earth’s heat content is stable, the radiative forcing parameter and the climate sensitivity parameter determines the final surface temperature that has been reached.
SJT “I am continually amazed at how many mind readers we have here, who know what Climate scientists think, when IMHO, they have absolutely no idea”.
What they think is reflected in their theories and their behavior. Most of them actually write it down, or have you missed that?
“What they think is reflected in their theories and their behavior. Most of them actually write it down, or have you missed that?”
Which is nothing like what they are accused of doing.
from what I’ve read of what climate scientists think in published articles it’s shameful what they think!
it’s not science, that’s for sure.
The report, Antarctic Climate Change and the Environment.
is available for download here
ftp://ftp.nerc-bas.ac.uk/pub/jtu/ACCE/
The Introduction to Chapter 5, the conclusion chapter, reports the following:
In other words they basically say they can’t predict anything with any accuracy then go on to do exactly that.
Jan Pompe ….I’ve got to get into Spice. I have a copy, but my brain has stalled and I have developed an inertia for experimenting. I still have a project in pieces, with piezoelectric problems. It’s a drum pad with piezo devices and they have lost their sensitivity (same complaint many girlfriends have had for me). I have used a conductive epoxy to reattach the leads but I am afraid to test it in case it doesn’t work. Maybe it’s just plain apathy.
The only use I had for Thevenin was passing an exam at a technological school. I get curious about how it all works and hope to get back into it one day, if I don’t run out of time. I am currently reprogramming myself for an additional 60 years on Earth, but I don’t know if the program will work or not. There just isn’t enough time in one lifetime to do everything a person needs to do.
“In other words they basically say they can’t predict anything with any accuracy then go on to do exactly that.”
In other words, they tell you they can’t predict anything with any accuracy, but go on to do their best since what is going to happen over the next century or so is going to be very important for decision makers now.
Eric Adler “You can’t prove a theory wrong or right by using an analogy”.
I think you are missing the point of the analogies. I certainly have not used analogies in an attempt to explain atmospheric conditions, I have used them to demonstrate the misuse of feedback in climate models. IMHO, modelers are misinterpreting the meaning of feedback or its requirements, and I think that is the sign of a mathematician trying to apply equations without understanding the physical nature of what he is doing.
The basic premise of positive feedback is gain. Without amplification in a system there is no point talking about positive feedback because it just wont happen. Therefore, the argument is over the existence of such an amplification. Physicists like G&T are claiming it’s not there, yet other physicists like Rahmstorf are using mathematical manipulations to claim it is there. I have never had faith in pure math if a visualization of the reality is not available, so I am very skeptical.
Using an electronic amplifier to demonstrate positive feedback gives people a visual of what it really is. They can see it in operation and compare that to the positive feedback alleged for the atmosphere. They can see that positive feedback requires amplification, otherwise the signal will decay.
The notion that water vapour is increasing in the atmosphere due to ACO2 increasing, and raising the temperature of the surface would be a positive feedback if it could do that. The 2nd Law of thermodynamics says it can’t. Other people are attacking the 2nd Law claiming it is satisfied as long as the ‘net energy level’ is positive. That is not what the 2nd Law states, and as G&T point out, the 2nd Law is about heat, not energy. You can’t just go changing laws to suit your paradigm.
Comparing the action in the atmosphere, as it is understood, to an electronic amplifier, with respect to feedback seems rational. Never mind the amplifier for a minute, just think about the feedback itself. The solar energy heats the surface, the surface heats the ACO2, and that back-radiates to the surface. What would be required for positive feedback? The surface would have to increase it’s temperature beyond the temprature it was heated by the solar energy so that an exponentially-increasing surface temperature condition could be established. Under those conditions, it would be fair to expect a thermal runaway eventually. Why that has never happened is the question.
The solar energy is constant with a spectrum of broad-band energy resembling a bell-curve. The energy emitted by the surface is in a narrower spectrum in the IR portion of the bell curve. It warms ACO2, which back-radiates over a different IR frequency band than the IR that warmed it. The back-radiated energy is energy lost by the surface, it is not an independent source like solar energy.
Because the surface is warmer than the ACO2, the 2nd Law states that the ACO2 cannot warm the surface beyond the temperature it was warmed by the solar radiation. This is an interlocked system in which the Sun cannot increase its energy, and the ACO2 is simply replacing energy the surface has already lost. There’s no way the ACO2 can warm the surface to a temperature higher than it was when the surface heated it. Otherwise, the 2nd Law is contravened.
There may be slight surface fluctuations as CO2 and WV levels vary in the atmosphere. Ultimately, the action seems to be one of finding a steady state in which the GHG’s in the atmosphere balance the losses of IR energy at the surface. The notion of positive feedback seems ruled out to me. Then again, what do I know?
Gordon: In the shell of a nut
I think you have outlined he problem. Mathematically it’s not impossible to travel backward in time, reduce total entropy, warm cool objects with even cooler sources of heat, all it take is a change of sign, but physically all of those events are quite related and quite unlikely.
SJT “this is the same thing that happened with Arthur Smith. A descent into incoherent ramblings, then a claim of victory…..”
I’m still trying to understand the point Arthur was making. He picked out a minor point in the G&T paper and tried to disprove it using what he described as a simple model. I thought his model made sense till he reached a conclusion that a deficit in radiative equilibrium MUST come from ACO2. When I asked him several questions about that, he ignored me.
A question I posed to him was why he focused on the greenhouse question while ignoring what I considered to be far more important issues. Again, he ignored me. All Arthur appeared to be doing was defending the status quo while missing an excellent opportunity to publicly debate important climate issues. He had no answers for the more difficult questions posed by G&T.
In response to Eric Alder’s last 3,000 words of theatre of the absurd:
Mark Twain once said: “It ain’t what you don’t know that gets you in trouble, but what you know for damn well sure.”
I agree – they can’t predict anything with any accuracy.
Their best is admiral, but not enough that I should alter my ways or expect my government, or any government, to do the same.
Nick Stokes “(Near) constant current sources are real……And you can create a practical one. You can run a 60W light from a 240V mains source, which is close to a voltage source…”
Nick…you’re confusing constant current with a constant current source. You said a 240 V mains is ‘close to a voltage source’. It is a voltage source. In a single-phase residential circuit, one of the slot you see in a wall outlet is at ground potential (0 volts) while the other is at 240 V, or 120 V, depending on where you live. Up here we use 120 because it is safer.
If you connect that 60 W bulb across the 240 V mains, you can apply the equation P = EI or VI. That means I = P/E = 60W/240V = 1/4 amp, as you say. That represents a constant current, but not a constant-current ‘source’. The voltage is the source and the constant current is dependent on it. You couldn’t use the current through the bulb as a source because the moment you tapped into it, the current would change.
If the bulb wattage changes to 120 W, the current changes to 1/2 amp while the voltage remains unchanged. The reason the current remains constant (relatively) is that the voltage is relatively constant and the bulb wattage is relatively constant. Either will drift a bit, but overall they are near-constant. Because their relationship is linear, through OHM’s Law, the current remains relatively constant.
Now look at this:
http://www.absoluteastronomy.com/topics/Differential_amplifier
Look at second drawing down on right side. At the bottom of the drawing, there is a circle with an arrow in it and identified as a constant-current source. The idea of a differential amplifier is to compare the two inputs and give an input that is relative to the difference between them. Since you want the actual difference in the inputs and not a difference due to other factors such as temperature drift, you want the resistance represented by the current-source to be high, which it is naturally, while maintaining a set current through the resistance. the CCS represents.
The circle with the arrow represents an arrangement of transistors which are configured to represent a high resistance with a constant current. The idea is that the current through the CCS remains constant when the voltage across it changes. That contravenes Ohm’s Law, so some sleight of hand is required to pull it off. An arrangment of transistor (inside the cricle with the arrow) is set up to accomplish that, but the effect is to fool the circuit into thinking the current through the CCS is constant even though the voltage across it is changing. That is accomplished by adjusting the current with transistors to keep it constant, but the current through the CCS comes from the powers supplies, +Vcc and -Vee.
It is vital to understand that the transistor circuits making up the CCS are dependent on a power supply voltage. There is no other way to to achieve a constant current without that power supply.
SJT “Don’t forget, we are just at the start of the major changes, and, from the changes in the Arctic, we could just as easily be underestimating as over estimating”.
You keep forgetting that major changes occured in the Arctic in the 1920’s. It was as warm then as it is now. What caused that warming? You don’t suppose it might have been related to multidecadal oscillations in the ocean, do you?
“You keep forgetting that major changes occured in the Arctic in the 1920’s. It was as warm then as it is now. What caused that warming? You don’t suppose it might have been related to multidecadal oscillations in the ocean, do you?”
Like I said, we are just starting.
Gordon
I not long ago replaced a electromagnetic clutch/brake controller that used lamps in series with the clutch or brake precisely because they are not constant resistance devices. The low starting resistance of the lamp allowed an extra current surge on activation of the clutch or brake causing a quicker response by the mechanical system. They have a positive temperature coefficient so for small changes in load you change not only the current but also the temperature of the filament and hence the resistance providing a negative feedback. An attempt to reduce the current by increasing the load resistance will reduce the resistance in the lamp thereby keeping it constant. It is example where we can get negative “feedback” through adaptive parameter control in a passive system. The voltage at the junction whoever will not be constant
A negative temperature coefficient device will tend to keep the junction voltage constant. In neither case however will there be a positive feedback that can increase the total power dissipation or provide gain. The most important point is that in either case if the load parameter is changed the source parameter changes to match more or less. Strictly speaking it’s not feedback but what we adaptive parameter control or just adaptive control. I have been considering setting up an experiment that high school kids can do I”ve got some bits and pieces but time is in short supply. Is it relevant to climate? To that I say maybe; I have long thought that we can’t really change the parameters for the out going IR without affecting the parameter for the incoming to compensate trouble is how to test this.
Comment from: Gordon Robertson April 6th, 2009 at 5:44 pm
Eric Adler “You can’t prove a theory wrong or right by using an analogy”.
I think you are missing the point of the analogies. I certainly have not used analogies in an attempt to explain atmospheric conditions, I have used them to demonstrate the misuse of feedback in climate models. IMHO, modelers are misinterpreting the meaning of feedback or its requirements, and I think that is the sign of a mathematician trying to apply equations without understanding the physical nature of what he is doing.
I am not missing the point at all. You are trying to prove a physical theory wrong, i.e. that WV concentration in the atmosphere will on average increase with an increase in temperature, and contribute a further increase in temperature, by appealing to an analogy in electronics.
If you want to prove the theory wrong, you have to apply physics to the real problem, not wheel out some electronic analog, which you cannot justify as an exact replica of the earth atmosphere system.
Sorry for misplacing the italics in the above post. My reply begins with the third line of italicized text.
Eric Adled
You are talking utter nonsense. Fact of the matter is that water vapour emissions at near surface temperatures from the lower troposphere have been more efficient due to the extra water vapour in the lower troposphere and the water vapour above the cloud levels has been on a slight reducing trend for the past 60 years lowering the averaged optical depth of the atmosphere to IR. There you have the basis of the negative feedback that Richard Lindzen and Roy Spencer have been seeing.
You can check the specific humidty for yourself here you’ll notice the downward trend in 700 mbar and above here:
http://www.cdc.noaa.gov/cgi-bin/data/timeseries/timeseries1.pl
and see a preview of the effect on whole atmopshere optical depth here:
http://miskolczi.webs.com/
about 3/4 down the page.
Comment from: Gordon Robertson April 6th, 2009 at 5:44 pm
Comparing the action in the atmosphere, as it is understood, to an electronic amplifier, with respect to feedback seems rational. Never mind the amplifier for a minute, just think about the feedback itself. The solar energy heats the surface, the surface heats the ACO2, and that back-radiates to the surface. What would be required for positive feedback? The surface would have to increase it’s temperature beyond the temprature it was heated by the solar energy so that an exponentially-increasing surface temperature condition could be established. Under those conditions, it would be fair to expect a thermal runaway eventually. Why that has never happened is the question.
You haven’t justified why it would be fair to expect a thermal runaway. Just like CO2, the effect of additional water vapor on the blockage of escape of radiation from the atmosphere is reduced as the concentration increases. We know that without WV and CO2 the earth would be 33C colder on average. This is a large temperature but not infinite.
The solar energy is constant with a spectrum of broad-band energy resembling a bell-curve. The energy emitted by the surface is in a narrower spectrum in the IR portion of the bell curve. It warms ACO2, which back-radiates over a different IR frequency band than the IR that warmed it. The back-radiated energy is energy lost by the surface, it is not an independent source like solar energy.
Because the surface is warmer than the ACO2, the 2nd Law states that the ACO2 cannot warm the surface beyond the temperature it was warmed by the solar radiation. This is an interlocked system in which the Sun cannot increase its energy, and the ACO2 is simply replacing energy the surface has already lost. There’s no way the ACO2 can warm the surface to a temperature higher than it was when the surface heated it. Otherwise, the 2nd Law is contravened.
The conclusion you have drawn from the second law of thermodynamics is incorrect. The simplest definition is:
http://en.wikipedia.org/wiki/Second_law_of_thermodynamics
Also, due to Rudolf Clausius, is the simplest formulation of the second law, the heat formulation or Clausius statement:
Heat generally cannot spontaneously flow from a material at lower temperature to a material at higher temperature.
In order to determine if the second law is violated you have to look at the total heat flow not only one component, not just to the back radiation, as you are doing.
The surface radiates more energy upward than the atmosphere radiates downward, and in addition there is convection and transpiration, which conveys energy from the surface into the atmosphere. The net result of this is that heat is flowing upward from the surface toward the atmosphere. It will continue to do so, if the surface becomes warmer as a result of the additional back radiation from water vapor that has been added to the atmosphere.
This argument has been made repeatedly on the web in response to G&T’s silly paper.
Further, the photons that are headed downward from the back radiation don’t carry any labels that say made at a lower temperature, and even if they did, the earth’s surface, which is a practically a black body in the IR spectrum, doesn’t know how to read such labels.
There may be slight surface fluctuations as CO2 and WV levels vary in the atmosphere. Ultimately, the action seems to be one of finding a steady state in which the GHG’s in the atmosphere balance the losses of IR energy at the surface. The notion of positive feedback seems ruled out to me. Then again, what do I know?
As the equations for feedback show, feedback is not equivalent to runaway, as long as the feedback coefficient is less than 1. Large feedback can cause runaway which was believed to have happened on Venus, which seems to have lost most of its water as a result of evaporation, dissociation and the loss of hydrogen due to solar wind.
I don’t want to get into a semantic discussion here about what precisely you mean by a positive imbalance in energy flux, but the situation is as I presented it. An increased forcing of some sort is necessary for an increase in average WV, likewise if forcing decreases, so will WV.
Comment from: Jan Pompe April 7th, 2009 at 1:08 am
Eric Adler
“I am not missing the point at all. You are trying to prove a physical theory wrong, i.e. that WV concentration in the atmosphere will on average increase with an increase in temperature, and contribute a further increase in temperature, by appealing to an analogy in electronics.”
You are talking utter nonsense. Fact of the matter is that water vapour emissions at near surface temperatures from the lower troposphere have been more efficient due to the extra water vapour in the lower troposphere and the water vapour above the cloud levels has been on a slight reducing trend for the past 60 years lowering the averaged optical depth of the atmosphere to IR. There you have the basis of the negative feedback that Richard Lindzen and Roy Spencer have been seeing.
You can check the specific humidty for yourself here you’ll notice the downward trend in 700 mbar and above here:
http://www.cdc.noaa.gov/cgi-bin/data/timeseries/timeseries1.pl
and see a preview of the effect on whole atmopshere optical depth here:
http://miskolczi.webs.com/
about 3/4 down the page.
Good,
You have stopped talking about electronics feed back equations.
Miskolczi’s paper can take up many internet forum threads. It is a very poorly written and obscure article. I have read it and the comments on it. From what I have read about it, I draw the conclusion that the equations, which he claims in the yellow box, show that the Greenhouse effect is working at its energetic top,heir energetic top, are actually just empirical observations. There are no physical principles that show that the equations are general and show that the greenhouse effect is limited as he claims.
Regarding the WV measurements from NOAA, I would like to know more about them.
I can’t figure out how global WV measurements were made at high elevations as far back as 1948. Is there any reference explaining the origin of this data? I have seen it referred to in the past, but haven’t yet found an explanation on how it was derived. Do you know?
Eric
“Good,
You have stopped talking about electronics feed back equations.”
Who died to make you arbiter of what is good science or engineering practice?
The use of analogue computers has been around a lot longer than the use of digital computers and they have been quite effective and this modelling is about solving equations (I know you didn’t ask for them and I’m wondering why you would avoid that) and it is just as valid to model them in an analogue system as it is in a digital one. This is something that I have done a number of times one machines and various production systems where I have modelled the behaviour of the machine for the controller with op-amps and a handful of passive components to optimise control where transducers for the feedback was not available with excellent results.
Quite frankly whether or not you think it’s valid is quite immaterial it works and it works well.
http://en.wikipedia.org/wiki/State_observer
it can be implemented with a digital or analogue (op-amp with a handful of componenets) computers.
I agree Miskolczi paper is difficult but not that difficult if you have a good instrumentation and control background.
People have been ballooning since the late 1700s and the readings for the highest altitude is only 300 mbar which is not all that high for a weather balloon considering the TIGR radiosonde profiles go up to 70,000m and 300 mbar is only ~9,000 m. Before the transistor arrived the scientists paid a bounty for the return of the instrument that had recorded the relevant data. IIRC about $5 which was good pocket money for kids in those days.
the equations derived in Appendix B are pretty straight forward and since he does not use the commonly used semi-infinite approximation in the derivation (it eliminates important exponential terms and hence the atmospheric IR window) and used empirical data instead of derived data to determine the boundary conditions it’s actually on a sound physical basis.
Comment from: Shawn H April 7th, 2009 at 1:21 am
Shawn H:Eric, I don’t understand what you are going on about, but if you think that the avg. water vapor follows ave. temperature and ave temp follows the forcing, then we don’t disagree. It, follows, thusly, that if you reduce the forcing to a negligible level, you will also reduce the level of WV. That is what I have been saying from my very first post on this issue.
Eric:Good. I expect therefore, that you don’t believe the constant positive imbalance of energy flux into the earth atmosphere system is needed to maintain a higher WV concentration based on the first law of thermodynamics.
I don’t want to get into a semantic discussion here about what precisely you mean by a positive imbalance in energy flux, but the situation is as I presented it. An increased forcing of some sort is necessary for an increase in average WV, likewise if forcing decreases, so will WV.
This is not a matter of semantics. The equations quoted in my post on page 33 distinguish between forcing and energy flux.
The energy flux is equal to dH/dt, the rate of change of the heat content of the earth. Since the WV will depend on the global average temperature T’, the WV concentration will be stable when dH/dt=0. So long as T’ increases the average WV concentration will continue to increase, at least if we believe the recent satellite measurements analysed by Dessler. T’ is the temperature referenced to the same initial state as the radiative forcing. The equation shows that a constant positive value forcing will increase the temperature until dH/dt= 0, ie equilibrium is reached.
So an increase in WV concentration does not require an increase in forcing, until an equilibrium state has been reached, and T’ is constant. However an increase in forcing should kick off an increase in temperature, and will result in an increase in WV.
As I pointed out earlier, and others agreed, once an average concentration of WV exists, whether it is higher or lower than before, it takes no additional energy from the climate system to maintain it at a constant value.
Jan Pompe wrote:
People have been ballooning since the late 1700s and the readings for the highest altitude is only 300 mbar which is not all that high for a weather balloon considering the TIGR radiosonde profiles go up to 70,000m and 300 mbar is only ~9,000 m. Before the transistor arrived the scientists paid a bounty for the return of the instrument that had recorded the relevant data. IIRC about $5 which was good pocket money for kids in those days.
So you believe that the data you pointed me to was derived from weather balloon measurements versus altitude. I agree that such technology was available in 1948.
This leads to a lot of other questios. What kind of geographical coverage was available? How often were tropical oceans and the less developed parts of the world covered? How good and uniform was the technology? Are there instrumental biases versus time buried in their like the temperature data? Do you know the answers to these questions? Determination of the significance and validity of the data is a job for scientists who specialize in these questions.
Certainly the uncorrected radiosonde temperature data was determined to be worthless for tracking temperature change versus elevation. Here is an example of one paper on the subject.
There are many more.
http://cat.inist.fr/?aModele=afficheN&cpsidt=2253208
Have any similar papers been written on the humidity data from balloons?
Eric “This leads to a lot of other questios”
Questions that you should be asking of the NOAA it’s their data set.
“Determination of the significance and validity of the data is a job for scientists who specialize in these questions.”
Precisely there has been quite a bit of reanalysis of radiosonde humidity data but at the end of the day one does the best he can with what is available. the paper you cited does not say they were useless but that care needed to be taken to use the correct model for the corrections. If the fiduciary data is kept (unfortunately it was not for some radiosondes’ series) then corrections can be made if not then you don’t know what instrument was used and reanalysis and hence correction impossible. One hopes that an organisation like NOAA does a good job.
Eric,
This is not a matter of semantics. The equations quoted in my post on page 33 distinguish between forcing and energy flux.
But they don’t explain what a positive imbalance in heat flux is. Is it an condition where more heat is being absorbed by the Earth than it is emitting? If so, how is this relevant to the average level of WV in the atmosphere IYO?
So an increase in WV concentration does not require an increase in forcing, until an equilibrium state has been reached, and T’ is constant. However an increase in forcing should kick off an increase in temperature, and will result in an increase in WV.
So how does ave. WV increase without an increase in temperature?
As I pointed out earlier, and others agreed, once an average concentration of WV exists, whether it is higher or lower than before, it takes no additional energy from the climate system to maintain it at a constant value.
Well, this is a highly debatable point IMO. To me, it seems pretty clear that the higher up the water condenses, the less of it will return to the surface. This strongly implies that heat released into the atmosphere will be lost to space at a faster rate than heat that stays near the surface.
If all WV was lifted to the stratosphere, before it condensed this would have a cooling effect on the surface. The stratosphere would warm, and the surface would cool, everything else being equal. However, we are supposed to believe that WV that condenses halfway to the stratosphere has no cooling effect, vis a vis water that condenses at the surface.
Oops, above “less of it” should read “less heat”
Shawn,
You need to distinguish between concentration of water vapor and rate of transpiration.
Transpiration transports heat into the upper troposphere. Higher concentration of water vapor directs some of the heat back to the surface. This heat will help keep the surface temperature from decreasing if there is a higher rate of transpiration. I suspect this is one of the phenonema that keeps the runaway greenhouse effect from occurring.
If there is an increase in transpiration this would presumably be taken into account by the models. I will have to do some research to find out whether the rate of transpiration/precipitation increases and by how much.
Eric
“The use of analogue computers has been around a lot longer than the use of digital computers and they have been quite effective and this modelling is about solving equations (I know you didn’t ask for them and I’m wondering why you would avoid that) and it is just as valid to model them in an analogue system as it is in a digital one. This is something that I have done a number of times one machines and various production systems where I have modelled the behaviour of the machine for the controller with op-amps and a handful of passive components to optimise control where transducers for the feedback was not available with excellent results.”
I have already pointed out to you, there is an electronic device you need that has been invented yet. If you are going to incorporate op-amps in your analysis, they are not passive, they are active. Thevenins Theorum does not apply any more.
Will
let me complete that for you properly this time
Nothing of any value.
Shawn wrote:
Well, this is a highly debatable point IMO. To me, it seems pretty clear that the higher up the water condenses, the less of it will return to the surface. This strongly implies that heat released into the atmosphere will be lost to space at a faster rate than heat that stays near the surface.
It is true that the about 1/2 of the heat radiated from the topmost layer of the troposphere by greenhouse gases escapes directly into outer space, and transpiration is one mechanism that brings heat up to that level. The fact that it is colder at that altitude than it is at the surface, is what keeps more heat from escaping via radiation than would be the case if there were no GHG’s in the troposphere.
If all WV was lifted to the stratosphere, before it condensed this would have a cooling effect on the surface. The stratosphere would warm, and the surface would cool, everything else being equal. However, we are supposed to believe that WV that condenses halfway to the stratosphere has no cooling effect, vis a vis water that condenses at the surface.
At the present time, this is a hypothetical that is not expected to happen ever.
The stratosphere is a region of temperature inversion and the lowest temperature is found at the tropopause, so any condensation will be below the stratosphere.
The concentration of WV in the stratosphere is very low ~ 6ppMV. Only a small amount of WV crosses the tropopause from the troposphere into the stratosphere. A good part of the WV in the stratosphere comes from oxidation of methane. Even at these low concentrations the study of WV in the stratosphere is important.
http://www.aero.jussieu.fr/~sparc/Initiatives/h2o.html
SPARC INITIATIVES : Water Vapour in the Upper Troposphere and Stratosphere
Jan Pompe,
A quote from the above web page, produced in 2002, describing the efforts to measure WV , casts doubt on radiosonde measurements of upper tropospheric humidity. This is what you said is the source of the NOAA data that you pointed out showing decreasing humidity with time.
The operational radiosonde network does not produce water vapour data that can be used for either analyses of long-term change, process studies in the upper troposphere, or for validation of UTH measurements. However, emerging data sets from improved quality, quasi-operational aircraft and ground-based instrumentation show promise and should be used more extensively for process studies, climate analyses and validation of satellite data.
That would be why scientific papers show increases in WV in the atmosphere over time, despite the decreases shown in the NOAA data set that you pointed to.
“Will
I have already pointed out to you
let me complete that for you properly this time
Nothing of any value.”
Which is how you always win your debates. You argue for what appears to you to be a long enough period of time, you choose to ignore what you can’t or do not want to understand, you declare yourself the winner. (In your own mind at least.)
Will there is no debate going on with you since you are shooting from the fingertips from an base of ignorance.
It’s not my jog to educate you. I will give you this much though If you can write a differential equation for the macroscopic effect, it can be implemented, even with clockwork analogue computers though it will be a tad more difficult.
Now as I have pointed out to you before you need to get you head down and tail up and do some real study.
Comment from: Jan Pompe April 7th, 2009 at 9:23 am
Eric
“I will have to do some research to find out whether the rate of transpiration/precipitation increases and by how much.”
you might as well start here:
http://www.mindfully.org/Air/2002/Decreased-Pan-Evaporation1nov02.htm
An interesting paper in pan evaporation data, which is taken on land. It shows a decrease over time. The author concludes the decrease is due to a reduction in solar irradience. After 1950 solar irradience has declined slightly, reducing the rate of pan evaporation.
This is not a good place to start research, because the ocean covers 70% of the earth’s surface, and is reponsible for the overwhelming majority of the water vapor in the atmosphere. The environment is totally different from the water limited environment on land where the pan evaporation measurements are made, as the author of the paper points out.
Eric as far as I’m aware it’s still very much the subject of debate as it appears that there aren’t many that accept Farquar’s conclusion it was just a starting point for you. To give you a hint where to look further perhaps. Others have suggested though I can’t recall who and I seem to have mislaid the links to it that increased afforestation on land has led to a reduction in wind velocity on land. I have no opinion on the matter.
My, aren’t we hung up in electrical theory!
To be so strung out in a web of solid state and network theorems now, it invites the carcass to be sucked dry of further analogies.
Jan Pompe wrote
The use of analogue computers has been around a lot longer than the use of digital computers and they have been quite effective and this modelling is about solving equations (I know you didn’t ask for them and I’m wondering why you would avoid that) and it is just as valid to model them in an analogue system as it is in a digital one. This is something that I have done a number of times one machines and various production systems where I have modelled the behaviour of the machine for the controller with op-amps and a handful of passive components to optimise control where transducers for the feedback was not available with excellent results.
I am sure that you have had a great career in industry using analog computers.
However, the question in my mind is, if analogue computers are so great, why don’t climatologists use them to do modeling of the climate instead of running GCM’s on super computers?
Why don’t they use circuit elements to represent the oceans, land masses, the behavior of clouds, water vapor feedback etc.? They are spending tons of money on these computers and lots of time programming and running them. Why don’t they just hook up some resistors and op amps and power supplies and meters to measure input an output wave forms, and voila, they have the answer?
Are they out to waste money, are they uneducated and stupid, or maybe, just possibly could it be that analog computers are not suited to the modeling of the climate because of the complexity of the problem?
This is an honest question. What is your opinion?
Eric
http://en.wikipedia.org/wiki/Analog_computer#Analog_digital_hybrid_computers
Darn it again i have left out a backslash.
Comment from: Jan Pompe April 7th, 2009 at 11:34 am
Eric as far as I’m aware it’s still very much the subject of debate as it appears that there aren’t many that accept Farquar’s conclusion it was just a starting point for you. To give you a hint where to look further perhaps. Others have suggested though I can’t recall who and I seem to have mislaid the links to it that increased afforestation on land has led to a reduction in wind velocity on land. I have no opinion on the matter.
Please explain why a paper on the historical data on pan evaporation data in Siberia is giving any insight into the question of whether on a global basis models say there is going to be an increase in the transpiration rate due to global warming?
It would seem to me that the place to start would be some IPCC report, which summarizes the results of GCM’s on this question.
So far I have found a map which shows significant increases in rainfall ( what goes up must come down) in high latitudes, a significant decrease in subtropical rainfall, and a significant increase in a very narrow band right at the equator.
http://www.jamstec.go.jp/ipccwg1/meeting/070900/04.pdf
The projections of precipitation are one of the shakiest aspects of GCM’s. Here is a summary of the status:
http://www.knmi.nl/onderzk/klimscen/papers/Mitch_beersma.pdf
IPCC projections of future climate change
Advances and sources of uncertainty in climate modelling
…Climate processes and feedbacks
• Improved treatment of water vapour (water vapour feedback doubles warming)
• Probably greatest uncertainty arises from clouds; sign of net cloud feedback still
uncertain
• Precipitation processes uncertain; difficulties with simulating precipitation amounts
and frequencies
….
Precipitation projections from AOGCMs
• Decrease of snow cover and sea-ice extent
• Globally average precipitation and evaporation are projected to increase
• Regionally both increases and decreases in precipitation are seen
• Increases in mean precipitation will likely lead to increases in variability
• The frequency of extreme precipitation events is projected to increase almost
everywhere
Do your analog computations provide any insight into this problem?
Eric I should add the cost factor For instance the autopilot on passenger planes for a long time continued to be hydraulic because it was tried and true analogue computing system. However to give you an idea a capacitor and resistor is cheaper than a dashpot and a few lines of code cheaper than a capacitor and resistor and you only have to pay for the lines of code once then cut paste or use functions or subroutine every time you need it. Every time you need extra hardware you have to buy it. The purely digital systems generally work out a lot cheaper in the long run.
Comment from: Jan Pompe April 7th, 2009 at 12:25 pm
Darn it again i have left out a backslash.
It is a hazard of the system. No way to preview or edit.
The Wiki entry was a good explanation of what analogue computers are good for.
However, it seems they are used for rapid computations of addition, integraton, multiplication etc., rather than simulation of physical processes by structuring circuit elements to represent parts of the system.
This discussion got started, which is what you originally were arguing about, when you said that the sort of feedback equations I showed that are used by climatologists to explain climate feedback are not good electronic examples.
You haven’t really answered the question I asked, which is why do you believe climatologists are using super computers to do their problems, rather than analog computers or hybrids?
Eric
No they don’t, you have get the model right regardless of the system you use. The only advantage is time i.e. speed of execution and if you inadvertently try to violate the laws of physics in the implementation it doesn’t work. It doesn’t necessarily tell you why it doesn’t work. Even with analogue systems garbage in -> garbage out.
However precipitation and evaporation have not been areas of interest for me so I have not formed much of an opinion on what is going on there.
Eric “You haven’t really answered the question I asked, which is why do you believe climatologists are using super computers to do their problems, rather than analog computers or hybrids?”
It’s cheaper. You need hardware elements for each concurrent process that you want to do on a supercomputer all you need is a subroutine run serially pretending to be concurrent. Quite frankly I don’t think it is worth the cost. Generally they save that sort of thing for the $300M+ satellites they send to the bottom of the Atlantic Ocean.
Analogue computers do just as they say; rapid computations but that is what simulations are whether done in a digital computer or an analogue one.
The point I’ve been trying to make is that if you have difficulty seeing heat draining from a cup is a similar mathematical problem to a capacitor discharging through a resistor then really you would have no business trying to implement either in a digital computer. Its that mathematical similarity why analogue computers work.
“The point I’ve been trying to make is that if you have difficulty seeing heat draining from a cup is a similar mathematical problem to a capacitor discharging through a resistor then really you would have no business trying to implement either in a digital computer. Its that mathematical similarity why analogue computers work.”
You have absolutely no idea what they think, or why they do what they do. You are just fabricating fantasies in your own mind.
Eric Adler “I am not missing the point at all. You are trying to prove a physical theory wrong, i.e. that WV concentration in the atmosphere will on average increase with an increase in temperature….”
That’s not what I’m trying to prove. I have no issue with WV increasing with temperature. I’m trying to prove that ACO2 can’t increase the surface temperature by playing a role in a positive feedback mechanism that increases WV. That’s where the electronics analogue comes in but the analog is not part of the proof, it’s simply an example of positive feedback to demonstarte how it works.
I did include an explanation for you with no amplifier involved. I pointed out that ACO2 was derived from a loss of energy at the surface, therefore it can’t act in a manner to increase surface temperature since it’s making up for a the loss that created it.
Will
You are in fantasy land please let us know when you have returned.
Janama “In other words they basically say they can’t predict anything with any accuracy then go on to do exactly that”.
The IPCC did the same thing in TAR. I can find it for you if you like. They claimed that future climate states cannot be predicted, then they went and did it using computer model probabilities.
SJT “In other words, they tell you they can’t predict anything with any accuracy, but go on to do their best….”
Do you call doing their best stifling satellite data and pushing virtual science? They did their best to discredit the satellite data with some mealy-mouthed allegations that the satellite data was now in line with the model predictions. Isn’t that a little backwards? I would think real scientists would try to find out why their model predictions are not exactly like the satellite data.
Furthermore, real scientists would stick with direct observation instead of turning to probabilities.
“You are in fantasy land please let us know when you have returned.”
Usually if you have a claim, you have to provide some evidence. Where is your evidence?
Jan Pompe “Mathematically it’s not impossible to travel backward in time, reduce total entropy, warm cool objects with even cooler sources of heat, all it take is a change of sign…”
That was also one of my failings at university. I’d work out a problem flawlessly on an exam, get near the end of the calculations and lose a sign trying to work things out in my head. Or, worse still, make an error in basic arithmetic after working through 3 pages of a Bessel function. If the prof was a nice guy, he’d allow for the small error, even though it could lead to me blowing something up in real life.
Granted, that’s not the same thing as reversing a sign because you don’t understand the theory.
Will I never thought that you would ask.
Proof you want proof you shall get.
Positive proof that Will is in fantasy land.
” The point I’ve been trying to make is that if you have difficulty seeing heat draining from a cup is a similar mathematical problem to a capacitor discharging through a resistor then really you would have no business trying to implement either in a digital computer. Its that mathematical similarity why analogue computers work.
[Note: nothing about how anyone thinks then from little Will]”
You are making the claim about what the modelers know or don’t know. I’m asking for evidence that supports your claim.
Gordon
LOL as if you’d be the first engineer to blow something up or that last. I can tell you 240 volts across an led can be quite entertaining. I don’t think you are fully qualified unless you’ve done it at least once. 😉
Indeed not in the one case you know when you’ve made a mistake the latter is a systemic problem. Like I once had with a graduate engineer who couldn’t get his head around feedback stuffed around with a motor speed control control that was running away for days after I had told him that he had the tacho generator wires reversed. When I went in to see exactly what he was doing I reversed those wires changed nothing else and the machine worked as advertised. The difficulty then is what do you tell the customer who has lost tens of thousands in extra down time alone? How do you charge him for the upgrade that should have worked the day it was installed? It was never the less an object lesson in what positive feedback does.
Now we have people who equally don’t understand feedback (positive or negative) telling us we need to spend trillions to correct a positive feedback problem in a system where the wires can not be reversed.
“Now we have people who equally don’t understand feedback (positive or negative) telling us we need to spend trillions to correct a positive feedback problem in a system where the wires can not be reversed.”
Delusions of grandeur. That can be treated.
Will
Will you are in fantasy land till I’ll post the statement again with some emphasis
Is that the best you can do? A bit of ad hominem.
Now let’s have you show how gain is possible in a passive dissipative system i.e. one without an internal power source. Let’s see some good physics from you.
Put up or shut up.
Jan; back off a bit. You are not the only one here who has practical experience in analogue technologies as crude as they were and industrial PLC etc.
Gordon too; this BS about electrical old theory being a good a substitute for fresh climate science is quite embarrassing.
In the extreme it’s a very narrow path you both tread. For instance; I once had a lot of work around industry in evaporation and drying techniques and I expect to see comments here that at least involve some knowledge of liquids in thin films, turbulence in stream flow, or vortexes as heat transfer engines and so on.
BTW in constant current sources and their analysis we see the 240 V mains power supply as an infinite source of energy just like the sun unless I’m very mistaken. Also my personal experience of litter tray evaporation in the back yard indicates climate change over several decades despite that too often quoted paper generated at ANU down the road.
For the novice; an old instrument man’s trick is to do your own observations every time before making a judgement on what your are told may be happening.
Gavin you are coming across like a technician trying to draw an engineer into a pissing competition. If so I’m not interested I’ve seen enough of that on the machine shop floor.
If you really want to help will out then perhaps you can either demonstrate that positive feedback can happen in a dissipative system or you can demonstrate that earths climate system is not a dissipative one. The choice is yours. Try to avoid the usual irrelevant obfuscation that you usually indulge in.
Bleating about using your finger as a voltage probe isn’t going to do it either.
“If you really want to help will out then perhaps you can either demonstrate that positive feedback can happen in a dissipative system or you can demonstrate that earths climate system is not a dissipative one. The choice is yours. Try to avoid the usual irrelevant obfuscation that you usually indulge in.”
Ice melts in the Arctic. The albedo changes is lower, because sea water is darker than ice, the earth absorbs me heat. The ice melts faster.
Jan
Your problem with your analogies to electrical circuits is that they use idealised components, and don’t change their properties. Perhaps if you had a type of resistor that, when it reached a certain temperature, started to lose it’s resistance properties. As it lost resistance, more current flowed through it, heating it more. Positive feedback.
Comment from: Gorodn Robertson April 7th, 2009 at 3:42 pm
Eric Adler “I am not missing the point at all. You are trying to prove a physical theory wrong, i.e. that WV concentration in the atmosphere will on average increase with an increase in temperature….”
That’s not what I’m trying to prove. I have no issue with WV increasing with temperature. I’m trying to prove that ACO2 can’t increase the surface temperature by playing a role in a positive feedback mechanism that increases WV. That’s where the electronics analogue comes in but the analog is not part of the proof, it’s simply an example of positive feedback to demonstarte how it works.
I did include an explanation for you with no amplifier involved. I pointed out that ACO2 was derived from a loss of energy at the surface, therefore it can’t act in a manner to increase surface temperature since it’s making up for a the loss that created it.
The last paragraph is nonseniscal. ACO2 is a chemical compound. It was not derived from a loss of energy at the surface.
Atmospheric CO2 and H2O, absorb radiation, collide with neighboring gas molecules to share the energy gained from absorbing radiation, and/or re-radiates the energy it has absorbed. That is what the physics says. The laws of physics have no way of instructing the stupid CO2 or H2O atom about where the energy originated so that it can prevent them from “acting in a manner to increase the surface temperature”.
Similarly for the water molecule that is absorbing energy from the back radiation, and may become energetic enough to evaporate from the surface of the ocean. The laws of physics have no way of telling the atom that it can’t evaporate now, because it would cause positive feedback.
As a matter of fact, the disappearance of water vapor from Venus is believed to be a result of a greenhouse effect runaway phenomen.
What you are saying is reminiscent of some kind of Gaia cult.
Will Again it’s the basic physics that has you confused
Do you really believe it makes a lot of difference? and the angle of incidence at the poles the most of the light sail right past what does fall on the water which is a dielectric falls on such a shallow angle it is mostly reflected. ON the other hand emissions from the darker water go straight up and is not modified by the angle of incidence at all. With the warmer water and all emissions from the surface also increase at a rate of 4.6 Wm^-2K^-1 all in all losing the ice caps will in fact have a net cooling effect. Did you not notice the cooling after the big melt in 2007?
Then there remains the question whether this is feedback. If it’s due to orbital factors i.e. more insolation then it’s a feed forward adaptive effect since it is a direct response to input. If due to more retention for instance due to increasing optical depth you need to show that this melting of the ice does not cool the system I think you’ll find that it will. Just put some ice cubes in a glass of room temperature water will drop as the ice takes it latent heat of fusion from the water.
Eric:It is true that the about 1/2 of the heat radiated from the topmost layer of the troposphere by greenhouse gases escapes directly into outer space, and transpiration is one mechanism that brings heat up to that level. The fact that it is colder at that altitude than it is at the surface, is what keeps more heat from escaping via radiation than would be the case if there were no GHG’s in the troposphere.
If there is condensation at a high level, then the temperature at that level is higher than if *there were no evaporation at all*. Thus, more heat escapes when there is more high level condensation, than when there isn’t. BTW, are you using transpiration as distinct from evaporation (ie evaporation from plant leafs) or are you using the two terms interchangeably?
At the present time, this is a hypothetical that is not expected to happen ever.
The stratosphere is a region of temperature inversion and the lowest temperature is found at the tropopause, so any condensation will be below the stratosphere.
The concentration of WV in the stratosphere is very low ~ 6ppMV. Only a small amount of WV crosses the tropopause from the troposphere into the stratosphere. A good part of the WV in the stratosphere comes from oxidation of methane. Even at these low concentrations the study of WV in the stratosphere is important.
Yes, I know that we will not be able to force all condensation to take place in the stratosphere anytime soon(Thank goodness). My point was a simple thought experiment. If heat(from condensing WV) emitted at the height of the stratosphere would be strongly cooling compared to heat emitted from the surface, then heat emitted part of the ways towards the stratosphere will be cooling more strongly than the same amount of heat emitted from the surface.
Comment from: Shawn H April 8th, 2009 at 1:10 am
Eric:”It is true that the about 1/2 of the heat radiated from the topmost layer of the troposphere by greenhouse gases escapes directly into outer space, and transpiration is one mechanism that brings heat up to that level. The fact that it is colder at that altitude than it is at the surface, is what keeps more heat from escaping via radiation than would be the case if there were no GHG’s in the troposphere.”
If there is condensation at a high level, then the temperature at that level is higher than if *there were no evaporation at all*. Thus, more heat escapes when there is more high level condensation, than when there isn’t. BTW, are you using transpiration as distinct from evaporation (ie evaporation from plant leafs) or are you using the two terms interchangeably?
Eric:
“At the present time, this is a hypothetical that is not expected to happen ever.
The stratosphere is a region of temperature inversion and the lowest temperature is found at the tropopause, so any condensation will be below the stratosphere.
The concentration of WV in the stratosphere is very low ~ 6ppMV. Only a small amount of WV crosses the tropopause from the troposphere into the stratosphere. A good part of the WV in the stratosphere comes from oxidation of methane. Even at these low concentrations the study of WV in the stratosphere is important.”
Yes, I know that we will not be able to force all condensation to take place in the stratosphere anytime soon(Thank goodness). My point was a simple thought experiment. If heat(from condensing WV) emitted at the height of the stratosphere would be strongly cooling compared to heat emitted from the surface, then heat emitted part of the ways towards the stratosphere will be cooling more strongly than the same amount of heat emitted from the surface.
The only thing that this shows is that positive WV feedback is a matter for calculation by models.
Just because transpiration happens and it is a cooling mechanism doesn’t prove that positive feedback cannot happen. The enhanced water vapor due to transpiration is a warming mechanism which sends more radiation back to the surface and permits less radiation to escape.
It is incorrect to look only at one phenomenon without looking at the other to draw conclusions.
Increased transpiration doesn’t mean that a higher level of CO2 cannot cause a higher average level of H2O which causes sufficient temperature increase at the surface to support a higher level of transpiration. This is not a qualitative question that can be settled by some basic principle of physics, but quantitative question that can only be settled by calculations and observations.
Your thought experiment doesn’t really shed any light on the quantitative question. We already knew that transpiration transfers heat to the upper troposphere in the tropics. That is why climate scientists expect warming of the upper troposphere in the tropics when the surface warms. Incidentally, that is why the initial UAH analysis, of the temperature data, in the upper troposphere, was suspected, to be mistaken. This was subsequently verified.
The only thing that this shows is that positive WV feedback is a matter for calculation by models.
Just because transpiration happens and it is a cooling mechanism doesn’t prove that positive feedback cannot happen. The enhanced water vapor due to transpiration is a warming mechanism which sends more radiation back to the surface and permits less radiation to escape.
It is incorrect to look only at one phenomenon without looking at the other to draw conclusions.
Except for your first sentence, I actually agree with this. My argument has always been with the folks who claimed that you could maintain a higher level of WV without any increased cooling. If that has not been your position, I don’t understand you at all.
Perhaps, the increased cooling from WV is more than offset by increased warming from the GHE. However, from pretty simple math it does follow that the WV will become less positive as WV increases. If the GHE increases logarithmically with increases in WV and the cooling effect of WV increases linearly, then sensitivity to WV will decrease as WV rises.
Darn it,
…that the WV will become less positive as WV increases
should read
that the WV feedback will become less positive as WV increases
Comment from: Jan Pompe April 8th, 2009 at 12:33 am
Will Again it’s the basic physics that has you confused
” because sea water is darker than ice”
Do you really believe it makes a lot of difference? and the angle of incidence at the poles the most of the light sail right past what does fall on the water which is a dielectric falls on such a shallow angle it is mostly reflected. ON the other hand emissions from the darker water go straight up and is not modified by the angle of incidence at all. With the warmer water and all emissions from the surface also increase at a rate of 4.6 Wm^-2K^-1 all in all losing the ice caps will in fact have a net cooling effect. Did you not notice the cooling after the big melt in 2007?
Sorry but you are exaggerating the effect of angle in your post. At an angle of incidence of 80degrees, the albedo of water drops to .35, and at an angle of incidence of 70 it is about .13.
Since the tilt of the earth’s axis is 23 degrees there is plenty of opportunity for the Arctic Ocean water to absorb sunlight.
http://en.wikipedia.org/wiki/File:Water_reflectivity.jpg
This is well understood by scientists who determine the feedback effect of ice melt.
Contrary to what you might think scientists are not imbeciles, and you are not a genius by comparison.
Whatever cooling occurred after the big melt did not occur because the Arctic ocean absorbed solar radiation.
Then there remains the question whether this is feedback. If it’s due to orbital factors i.e. more insolation then it’s a feed forward adaptive effect since it is a direct response to input. If due to more retention for instance due to increasing optical depth you need to show that this melting of the ice does not cool the system I think you’ll find that it will. Just put some ice cubes in a glass of room temperature water will drop as the ice takes it latent heat of fusion from the water.
Sorry but ocean water warmed by the sun ultimately melts more ice which reflects less short wave radiation back to space and absorbs more solar radiation as open water. Scientists have found the opposite of what you say. You are deluding yourself.
Comment from: Shawn H April 8th, 2009 at 3:22 am
Eric:
“The only thing that this shows is that positive WV feedback is a matter for calculation by models.
Just because transpiration happens and it is a cooling mechanism doesn’t prove that positive feedback cannot happen. The enhanced water vapor due to transpiration is a warming mechanism which sends more radiation back to the surface and permits less radiation to escape.
It is incorrect to look only at one phenomenon without looking at the other to draw conclusions.”
Except for your first sentence, I actually agree with this. My argument has always been with the folks who claimed that you could maintain a higher level of WV without any increased cooling. If that has not been your position, I don’t understand you at all.
Perhaps, the increased cooling from WV is more than offset by increased warming from the GHE. However, from pretty simple math it does follow that the WV will become less positive as WV increases. If the GHE increases logarithmically with increases in WV and the cooling effect of WV increases linearly, then sensitivity to WV will decrease as WV rises.
Are you some kind of savant that you can calculate in your head simulations that it takes many scientists, reams of data, complex programs and super computer simulations to accomplish?
Do you have one of Pompe’s magic analog computers that can do all of this in real time?
Aren’t you guilty of overestimating your prowess here?
Eric
Where di I say that it did? Thank you for posting up that chart it makes my point quite nicely at 90 degree incidence reflectivity is 1 and emissivity goes up absorptivity = 1- reflectivity you need to multiply the light the arctic ocean will absorb by that figure. BTW I don’t know many serious scientists that claim massive albedo change due to polar ice melt only from people on the fringes like will and now you.
With a reflectivity of 1 for water at the poles I would say that that water and ice reflect the same up there. Then water emission is higher because that at least is not affected by an angle of incidence has a higher emissivity than ice and it’s warmer.
Eric can you produce a paper that gives some numbers? You shouldn’t really need to you have all the information that you need in the chart you linked to. Don’t you realise the Poles are as cold as they are because of the high angle of incidence? It will take you about 5 minutes to do the sums yourself.
Shawn,
One more thing. It does take heating of the surface to evaporate WV from the liquid state, but once it is in the vapor state, no additional energy is needed to supply to the air to keep it there as long as the WV concentration is below saturation level.
To keep temperature of the air constant the heat entering a region must equal what leaves it. If there is radiation balance, and radiational forcing has shifted the surface temperature to its new stable level, the radiation from the top of the atmosphere will equal the incoming solar radiation, and the temperature will remain constant. (We are of course speaking of averages)
.
Comment from: Jan Pompe April 8th, 2009 at 6:29 am
Eric
Whatever cooling occurred after the big melt did not occur because the Arctic ocean absorbed solar radiation.
Where di I say that it did? Thank you for posting up that chart it makes my point quite nicely at 90 degree incidence reflectivity is 1 and emissivity goes up absorptivity = 1- reflectivity you need to multiply the light the arctic ocean will absorb by that figure. BTW I don’t know many serious scientists that claim massive albedo change due to polar ice melt only from people on the fringes like will and now you.
The angle of the sun at the north pole 90 deg north does get as high as 23deg at the summer soltice. As you proceed further south, it gets higher than that.
Are these people on the fringes
http://adsabs.harvard.edu/abs/2008AGUFM.C44A..02P
The summer extent of the Arctic sea ice cover has decreased in recent decades and there have been alterations in the timing and duration of the summer melt season. This has resulted in changes in the evolution of albedo of the Arctic sea ice cover, and consequently in the partitioning of solar energy. These changes are examined on a pan-Arctic scale on a 25 x 25 km Equal Area Scalable Earth Grid for the years 1979 – 2007. Daily values of incident solar irradiance are obtained from ERA-40 reanalysis products and ice concentrations are determined from passive microwave satellite data. The albedo of the ice is modeled by a five-phase process that includes dry snow, melting snow, melt pond formation, melt pond evolution, and freezeup. The timing of these phases is governed by the onset dates of summer melt and fall freezeup, which are determined from satellite observations. Results indicate a general trend of increasing solar heat input to the Arctic ice-ocean system due to reductions in ice concentration and longer melt seasons. This trend may accelerate the loss of sea ice through the ice-albedo feedback. The evolution of albedo, and hence the total solar heating of the ocean, is more sensitive to the date of melt onset than the date of fall freezeup.
Eric:” Sorry but ocean water warmed by the sun ultimately melts more ice which reflects less short wave radiation back to space and absorbs more solar radiation as open water.”
With a reflectivity of 1 for water at the poles I would say that that water and ice reflect the same up there. Then water emission is higher because that at least is not affected by an angle of incidence has a higher emissivity than ice and it’s warmer.
Eric:
“Scientists have found the opposite of what you say. You are deluding yourself.”
Eric can you produce a paper that gives some numbers? You shouldn’t really need to you have all the information that you need in the chart you linked to. Don’t you realise the Poles are as cold as they are because of the high angle of incidence? It will take you about 5 minutes to do the sums yourself.
Here is an old one from 1961:
T HE surface albedo* and its change during the spring, summer and
autumn seasons is probably the most significant regional factor affecting
the heat budget of the Arctic Ocean basin. In the spring, when most of
the sea-ice is covered with snow, the albedo of the surface is between 80
and 90 per cent. In mid-summer, however, the snow cover melts, fairly
large puddles begin to appear on the sea-ice and the albedo becomes smaller.
In addition the total ice cover is reduced from nearly 10-tenths in the spring
to about %tenths in the summer, which lowers the albedo still further.
For studies of the surface and atmospheric heat budget of the Arctic
Ocean basin, it is important to determine representative albedo values for
various characteristic surfaces. The work reported here is one of the first
attempts to determine the albedo of various ice conditions in the Arctic
by aircraft.
http://pubs.aina.ucalgary.ca/arctic/Arctic14-3-188.pdf
Despite my documentation, my experience tells me that you will continue to delude yourself about this and find some other lame excuse to think what you want to think.
Are you some kind of savant that you can calculate in your head simulations that it takes many scientists, reams of data, complex programs and super computer simulations to accomplish?
Do you have one of Pompe’s magic analog computers that can do all of this in real time?
Aren’t you guilty of overestimating your prowess here?
I don’t need to calculate reams of data to answer this question. If I know that increases in GH gasses tend to heat the Earth proportionally to the logarithm of their concentration, and that the cooling effect of WV increases proportionally to its concentration, then as WV concentration rises then the ratio – heating effect of increased WV/cooling effect of increased WV will shrink as the concentration of WV rises.
One more thing. It does take heating of the surface to evaporate WV from the liquid state, but once it is in the vapor state, no additional energy is needed to supply to the air to keep it there as long as the WV concentration is below saturation level.
We already talked about this, but there is WV turnover every 9-10 days. This means that every 9-10 days on average a WV molecule will evaporate, rise from the ground some distance, then condense.
“We already talked about this, but there is WV turnover every 9-10 days. This means that every 9-10 days on average a WV molecule will evaporate, rise from the ground some distance, then condense.”
There are several factors that limit warming, but they aren’t likely to help us out soon enough.
Shawn,
I don’t need to calculate reams of data to answer this question. If I know that increases in GH gasses tend to heat the Earth proportionally to the logarithm of their concentration, and that the cooling effect of WV increases proportionally to its concentration, then as WV concentration rises then the ratio – heating effect of increased WV/cooling effect of increased WV will shrink as the concentration of WV rises.
You fail in comprehension.
The energy is required to evaporate water. Once the water is in the atmosphere it doesn’t cool anything. There are 2 variables of interest, which you continue to confuse with one another.
1) ,b>Rate of evaporation of water vapor. It takes about 2260 J/gm of to evaporate water.
That removes energy from the earth’s surface and takes it up into the atmosphere.
This is the cooling of the surface you are talking about.
2) Concentration of water vapor in the atmosphere. It takes 0 Joules to maintain a gram of water in the gaseous state. It will stay there if the temperature does not go below the dew point. If the average concentration of water vapor remains at a certain level, no additional energy is required to keep it there. It has no cooling effect in the gaseous state.
It prevents the escape of heat from the planet, by redirecting the up welling radiation back to the surface so less of it reaches the top of the troposphere. If the average temperature of the atmosphere remains higher, it takes no expenditure of energy to maintain a higher average concentration of WV in the atmosphere. As I pointed out, the increase in average concentration of 14% takes only about 9 hours of sunlight over a 100 year period, or 1X10-7 % of the solar radiation entering the earth over that period.
The models do show a higher global transpiration rate over all as a result of warming, but they also show, contrary to your notion, that the concentration of WV increases and contributes to the warming, by itself doubling the effect of CO2. There is no reason apriori to claim that the rate of evaporation is intrinsically related to the average concentration of WV in such a manner that there cannot be positive feedback.
Your idea is based on the mistaken concept that evaporation rate and concentration of WV in the atmosphere are the same thing.
Eric “
What I can’t find in that paper is where he factored in the angle of incidence of the incoming sunlight. In his calculations he is assuming the sun is directly overhead with an open water albedo of 4% at Cape Bathurst where reflectivity due to incident angle alone is ~13%. The combined effect then is ~16% is reflected. The number gets higher the further north or south you go. Do your sums Eric it isn’t hard. The emissivity doesn’t change much from ice to water but the radiance does by about 4 W/m^2/K at 0C since it is near to BB emissivity. The equation is DQ/dT = 4 sigma T^3 (do you need me to derive that for you?) if you want to work it out for yourself. You also went to the trouble of digging up the reflectivity chart for water so why don’t you use it?
Will
they exist we we call them negative temperature coefficient thermistors trouble is they tend to be power dissipation neutral. Given that P=EI as the the resistance goes down current goes up but voltage goes down proportionally so power dissipation will find it’s maximum when the resistance matches the source resistance or the system burns out whichever happens first. See here:
http://www.esnips.com/doc/1d10d862-46c8-4789-b38f-57110caac249/PassiveFeedback
We also have positive temperature coefficient thermistors (and the claim is that atmosphere behaves more like one of these than the negative version) but it’s the same deal. There is no free lunch here will.
Jan “Do your sums Eric it isn’t hard” is about the least humble contributer here IMO. However it seems we can get away from that pesky electrical engineering background with some arm twisting.
Gas laws, near saturated vapour at different temperatures and pressure, radiation blocking etc will be a whole new ball game with appropiate umpires.
Eric
Is there any reason to suppose that the gram of water in a gaseous state is not radiating energy away in all directions the portion that makes it to space at the very lest will need to be replaced if that gram of vapour is to remain a gram of vapour.
Gavin why don’t you try a little harder you might even start to make some sense.
If Eric actually did some sums he’d do better I’m sure. He went to the trouble to dig up a chart of water’s reflectivity dependance on angle of incidence of light but has failed to apply it.
Now Gavin do you think there is ice at the poles because it’s cold i.e. it does not receive much energy from the sun, or do you think it’s cold because there is ice?
Eric, I am assuming that precipitation goes up when the ave. WV level goes up and the turnover of a molecule of water stays about the same(@ 9-10 days), you are assuming that precipitation stays the same, while the turnover of a WV goes down(the average water molecule stays in the atmosphere longer).
Personally, I don’t think it is a stretch at all to say that a warmer, moister climate produces more precipitation.
Also, jan’s comment on this issue is also apt IMO.
Comment from: Jan Pompe April 8th, 2009 at 9:02 am
Eric “
http://pubs.aina.ucalgary.ca/arctic/Arctic14-3-188.pdf
Despite my documentation, my experience tells me that you will continue to delude yourself about this and find some other lame excuse to think what you want to think.”
What I can’t find in that paper is where he factored in the angle of incidence of the incoming sunlight. In his calculations he is assuming the sun is directly overhead with an open water albedo of 4% at Cape Bathurst where reflectivity due to incident angle alone is ~13%. The combined effect then is ~16% is reflected. The number gets higher the further north or south you go. Do your sums Eric it isn’t hard. The emissivity doesn’t change much from ice to water but the radiance does by about 4 W/m^2/K at 0C since it is near to BB emissivity. The equation is DQ/dT = 4 sigma T^3 (do you need me to derive that for you?) if you want to work it out for yourself. You also went to the trouble of digging up the reflectivity chart for water so why don’t you use it?
At the north pole in midsummer, the sun is at an angle of 23 degrees. The reflectivity of water from the chart is not almost 1 as you claimed in your original post on this subject, but rather it is about 0.1. The further south you go the smaller the reflectivity at the peak of the day will get. At 66 degrees, latitude which is the southernmost part of the Arctic circle, the albedo drops to about the same percentage as it is at vertical incidence, since at it peak during the day the sun is at 46 degrees. This will get lower as the daily time interval is extended beyond noon, and when the days are on either side of June 21.
I am not going to put in the effort put together a spread sheet to calculate a daily/hourly albedo chart versus latitude to satisfy your curiousity. I can safely assume the scientists who study albedo take this all into account. They certainly have the tools and education to do this task, and with so many working on this project, someone would have thought of it. The author of the paper I linked, that measured the albedo, mentioned that using a cloudy day, and measuring the albedo of diffuse light from clouds, creates an error, but claimed it was a small one.
It is clear that the albedo difference between ice and water makes a difference, and the angle of the sun will make a reduce this difference for part of a day, but it is not correct to consider the albedo of water 1 above the arctic circle as you have claimed in your initial post on this subject, when you claimed paradoxically that melting arctic ice has a cooling effect.
You asked for publications that showed that albedo was a significant positive feedback, and I provided a peer reviewed publication. There certainly are many. The effect has been recognized for many decades and has never been questioned.
I never asked you for a peer reviewed publication that showed that melting arctic ice has a cooling effect on climate. I am sure that you couldn’t produce one. I don’t doubt that there is some AGW denier crackpot out there that has some blogpost, but I won’t count that.
“You asked for publications that showed that albedo was a significant positive feedback, and I provided a peer reviewed publication. There certainly are many. The effect has been recognized for many decades and has never been questioned.”
Typically, the goal posts have been moved, a common tactic employed here.
Jan has denied that positive feedback is possible, now he is just arguing over how much.
Comment from: Jan Pompe April 8th, 2009 at 10:10 am
Jan Pompe wrote:
Eric
“It takes 0 Joules to maintain a gram of water in the gaseous state. It will stay there if the temperature does not go below the dew point. If the average concentration of water vapor remains at a certain level, no additional energy is required to keep it there. It has no cooling effect in the gaseous state.”
Is there any reason to suppose that the gram of water in a gaseous state is not radiating energy away in all directions the portion that makes it to space at the very lest will need to be replaced if that gram of vapour is to remain a gram of vapour.
There is no reason not to think so, since this is what happens. The ultimate source of this energy is the solar radiation continuously being absorbed, which results in upward IR emissions.
You have to look at the lapse rate of the troposphere, the radiation flow and the details of the water vapor concentration to see how this works. At the very top of the troposphere the radiated energy into space will equal the sun’s solar input when radiation balance is established. This is a larger amount of radiation then was previously emitted while the earth atmosphere system was absorbing energy and increasing its temperature as a result of the imbalance, such as we are observing currently. This means that the temperature at the top of the troposphere, where the radiation is being emitted, must go up somewhat from where it was when less energy was emitted to outer space. What keeps the temperature up is the flow of radiation from below, since the surface temperature has increased.
Eroc
Not in that paper that you posted the link to. You can’t use the peak angles where is is only for a short time you need also to take in diurnal variation and integrate it over the period. I’m not suggesting that you do it for my curiosity I can do that for my self but for your benefit.
I agree I should have been more careful but there is a point that tracks the Sun on the other side of the Pole where not the Albedo (I don’t think I claimed that it was 1) but the angle of incidence made the reflectivity 1 I don’t think it is the same thing.
Then i suggest you put some iced cubes in glass of water at room temperature and find out for your self if it warms the water up now that would be paradoxical.. The latent heat of fusion of water is 334 J/g that energy has to come from somewhere or do you think that it could melt without taking energy from the water it’s in?
Now kindly explain how it is paradoxical.
Comment from: Shawn H April 8th, 2009 at 12:10 pm
Eric, I am assuming that precipitation goes up when the ave. WV level goes up and the turnover of a molecule of water stays about the same(@ 9-10 days), you are assuming that precipitation stays the same, while the turnover of a WV goes down(the average water molecule stays in the atmosphere longer).
Personally, I don’t think it is a stretch at all to say that a warmer, moister climate produces more precipitation.
Also, jan’s comment on this issue is also apt IMO.
I am not assuming the precipitation remains the same. I accept that a warmer climate will tend to produce more precipitation. Whether the amount of precipitation is going to eliminate the possibility of positive feedback is something that I don’t see as an obvious assumption. This answer to this question requires a lot of measurement and simulation.
The people who model this stuff say precipitation goes up, but calculate the positive feedback of WV doubles the temperature change due to CO2.
By the way do you think positive feedback is impossible, and melting arctic ice is cooling the earth also?
No will <blockquote.now he is just arguing over how much.
It takes energy for the ice to melt it can’t do that without cooling the water that is melting it that is why positive feedback is impossible.
It’s pretty elementary thermodynamics that you put hot and cold together the hot cools the cool warms and if the cool is frozen it takes a lot more work on the that of the warm to achieve that equilibrium cooling it all the more. It’s all that pesky business about heat engines not being able to work if the heat is exhausted to the hot reservoir. Sorry Will you still don’t have a free lunch.
“It takes energy for the ice to melt it can’t do that without cooling the water that is melting it that is why positive feedback is impossible.”
You live in a strange universe where you can pick and choose the thermodynamic elements that fit your need at any particular time, while completely ignoring the system.
The earth is constantly being fed energy, massive amounts of it, every day, by the sun. If you make the surface darker, it is going to absorb more of that energy. The fact that the ice is melting in the Arctic is proof that the energy is there to feed the process, that fact that the sea will absorb more energy just means that it will make the earth warmer. Albedo change = positive feedback. Without the sun driving it all, there would not be anything much happening, it would all just freeze over, but with the sun driving things, the picture changes.
Eric :By the way do you think positive feedback is impossible”
I have never said it was impossible I have used it a lot in my designs BTW I was never an Electrical Engineer my training is Physics (Solid sate) EE was something I drifted into because I could do it and there was a living to be had.
I said it was impossible in passive dissipative systems I have made an attempt to explain why here
http://www.esnips.com/doc/1d10d862-46c8-4789-b38f-57110caac249/PassiveFeedback
The block diagrams do not represent electrical circuits though I do give an example by way of an electrical circuit, they represent.
If you want to put more water vapour into the atmosphere you need more energy put into the system to evaporate the water. That 2260 Joules more for every extra gram if we increase the optical depth of the atmosphere by extra CO2 or aerosols the temperature will go up because it takes longer too cool but it does not put more energy into the system it just retains what is there longer. If some of this energy retained in the atmosphere is going to evaporate more water it must cool atmosphere to do it but if the atmosphere is cooler than the surface then it doesn’t have the extra to give. .
Will
Sun must have fallen down on the job 2007.
no will i just don’t leave things out like angle of incidence at high latitudes and the fact that it takes more ~160 times the energy to melt a gram of ice than to heat it 1K and 80 times to heat 1g of water iK.
cohenite…I had not noticed that you linked to this site on the first page, which I came across independently:
http://www.geocities.com/atmosco2/atmos.htm?200820
Elsewhere on his site, Thieme claims that back-radiation is nonsense and that the greenhouse effect can be explained by the ideal gas law and gravity. That also explains the atmosphere of Venus. G&T think it’s nonsense because CO2 in the atmosphere cannot behave like a cavity resonator (blackbody), but they do link to Thieme’s site. That’s how I came across it..
I have been harping that the density of GHG’s in our atmosphere is far to rare to account for the so-called greenhouse effect. That’s especially true for ACO2. Some AGW types are getting tired of my rants about that but they need to read this article carefully.
The question is how did so many IPCC scientists, and other climate scientists, get sucked into the rare gas theory? Is it possible they latched on to the theories of Arrhenius without verifying the physics?
Louis…does this explain why it gets warmer as you tunnel into the Earth?
Jan Pompe “…do you think there is ice at the poles because it’s cold i.e. it does not receive much energy from the sun, or do you think it’s cold because there is ice?”
I was just wondering that about the ozone holes over the poles. Are they there because the ultraviolet violet that produces them is not only weaker at the poles, and is also striking them at nearly a perpendicular angle. The notion that they are caused by anthropogenic fluorides seems even more stupid than the notion that global warming is caused by ACO2.
“Will
The earth is constantly being fed energy, massive amounts of it, every day, by the sun
Sun must have fallen down on the job 2007.
You live in a strange universe where you can pick and choose the thermodynamic elements that fit your need at any particular time, while completely ignoring the system.
no will i just don’t leave things out like angle of incidence at high latitudes and the fact that it takes more ~160 times the energy to melt a gram of ice than to heat it 1K and 80 times to heat 1g of water iK.”
You are once again moving goal posts and confusing things. The question wasn’t, is there a feedback effect happening, it was, is it possible. You claim it is impossible, because you can’t model it with an electrical circuit. (BTW, I thought models were *out* here. Apparently not).
Clearly, there *will* be some sunlight hitting the surface of the sea, or the ice, whichever is present at that point in time, even if it is at an angle. If there is now sea water where there was once ice, there will be less radiation refected straight back into space. It’s a simple matter to understand.
If the change from ice to sea is due to global warming, and the earth is now getting warmer due to the change creating a new source of warming, then there is clearly a positive feedback.
If you can’t model it with passive components in an electrical circuit, then that’s your problem.
Gordon Mt Erebus venting HCl ~4 km below the stratosphere too may have something to do with it. I think the UV in the relevant band is probably mostly absorbed by O2 by the time it gets there having to pass through a lot of the atmosphere at that angle.
SJT “The fact that the ice is melting in the Arctic is proof that the energy is there to feed the process…”
The important question has to do with where the energy is coming from that melts the ice and why it’s only melting it in the Arctic. The solar energy at the surface is essentially a constant. To get a positive feedback, you have to increase that energy by making it dependent on a process on Earth. That’s not likely to happen, therefore you need a separate power source to add to the solar energy. The AGW theory claims that independent source is back-radiation from the GHG’s in the atmosphere but they are entirely dependent on surface IR, hence the solar radiation.
The back-radiation from GHG’s came from energy loss on the surface. The surface emits IR based on it’s temperature, which is based on its composition. Once there is an equilibrium between incoming solar radiation and emitted IR, the surface will generally stay at that temperature. However, it has lost energy to the atmosphere and only a small portion of that energy is absorbed by GHG’s because they only make up 1% of the atmosphere at best. The energy back-radiated, if it’s there at all, can only make up for a small amount of the initial energy lost from the surface. There’s no way it can increase the surface temperature beyond what it was heated initially by the Sun.
In order for positive feedback to be an issue, some sort of furnace would have to be introduced that could amplify the back-radiation to a point where it added energy to the surface to make up for the losses on the surface. When it had done that, then it could begin amplifying the surface heat. To realize that, the furnace would have to be dependent on ACO2, so that the temperature of the surface increases with increasing ACO2.
It’s obvious that natural CO2 does not create a positive feedback, otherwise we’d be like Venus. Why ACO2 should cause that condition has me scratching my head.
Will <blockquote. You claim it is impossible, because you can’t model it with an electrical circuit. (BTW, I thought models were *out* here. Apparently not).
No change in goal posts. First of all I gave an electrical examples after I presented the general case of the dissipative system the energy is continually being dissipated fist by the invers square law, then by absorption of near IR and some reflection of the SW and distribution of the energy before it reaches the surface (the summing junction in the block diagram) then it gets absorbed and distributed through the atmosphere (some of it LW IR) the potential continually decreasing as entropy increases now this high entropy distributed energy is of a lower potential than at the surface the summing junction it cannot therefore transfer back to that junction as heat ready to do more work like evaporate more water it can’t be done. Putting some numbers to it is not changing the goal posts.
The one changing the goal posts is you if you want to talk about feedback due to increasing CO2 the problem is the one with more ice melting due to increased CO2 or more water vapour due to more CO2.
The fact that you think it can’t be modelled with an electric circuit is your problem Will and I have news for you water doesn’t spontaneously run uphill either. Its all quite a different argument from just how effective melting polar ice will be in creasing net planetary absorption. There we optical issues as well as thermodynamic ones.
gavin “Gordon too; this BS about electrical old theory being a good a substitute for fresh climate science is quite embarrassing”.
It’s embarrassing because you are not comprehending what I am saying. I am using electrical theory ONLY to give an example of positive feedback and that it requires amplification to operate. A claim is being made that WV is increasing in the atmosphere due to ACO2 increasing the natural CO2 in the atmosphere, which increases back-radiated energy to the surface and warming it. That surface warming is theorized to evapourate more WV, increasing the atmospheric temperature due to it absorbing more surface IR. Then the cycle theoretically spirals out of control to a Hansen tipping point.
If the surface temperature warmed to a temperature higher than what the solar radiation warmed it, that would represent a positive feedback. Where is the amplification of surface temperature coming from? Some people claim it is solar radiarion, but it is relatively a constant and will not increase because there is a higher demand. That leaves only back-radiated energy from GHG’s. However, that energy came from the surface and represents a loss. Positive feedback needs a gain, so the back-radiation can do no more than recoup ‘some’ losses and can in no way provide a gain.
As Jeffrey Glassman pointed out, even Gavin Schmidt does not understand the physical nature of positive feedback. He couldn’t even get the math right in his rebuttal to Glassman. That means Hansen doesn’t understand it either.
I’m not trying to be arrogant or stupid here, but unless you’ve actually worked with positive feedback, as you must in electronics, there’s a good chance it will only be a concept to you.
With respect to the 240 V mains as a constant voltage source, that’s only true if the demand is low enough. The more people come online, the more current is drawn, and the more internal losses in the generator reduce the output voltage. In the States, they have ‘brown outs’, where the voltage drops so low that light bulbs dim. Our mains voltage is normally around 118 volts, but it will vary depending on the demand. That’s why electrical devices sometimes come with taps on the power transformer. By retapping the transformer, you can make up for low mains voltages.
SJT “Ice melts in the Arctic. The albedo changes is lower, because sea water is darker than ice, the earth absorbs me heat. The ice melts faster”.
You make it sound like you’re doing all this in a thimbleful of water. How about that Mother of Heatsinks surrounding the ice? We call them oceans up here. Even if what you say is true, how long is all this going to take and why haven’t we seen any of it yet?
SJT “Perhaps if you had a type of resistor that, when it reached a certain temperature, started to lose it’s resistance properties. As it lost resistance, more current flowed through it, heating it more. Positive feedback”.
We have something kinda similar, it’s called a transistor. There are, of course, thermistors, which vary their resistance with temperature, but you’ll never get positive feedback from a thermistor. You could set up a transistor circuit to emulate what you describe above but that still would not be positive feedback.
The only way you can get positive feedback is to take a portion of an output signal and send it back to the input of an amplifier so that it reinforces the normal input signal. That way the output becomes larger on each feedback cycle. It wont work without the amplification because you want to increase the output beyond what it would be with the normal input signal. In a normal amplification system, positive feedback is an undesirable quantity because it destabilizes the system by making it runaway on itself. I think we mentioned the squealing of a sound system when the microphone is too close to and in front of the speaker system.
In the atmosphere, you not only want to feedback heat from the atmosphere to the surface, you want it to overcome the loss of heat from the surface that created it, then reinforce the solar radiation. That is just not possible without an outside source of heat.
BTW…according to Thieme, NASA no longer lists back-radiation in its energy budget diagram. I don’t know how they account for WV increases due to ACO2.
http://eosweb.larc.nasa.gov/EDDOCS/images/Erb/components2.gif
Jan Pompe…we’ve all done that. One episode scared the heck out of me. I had a blown computer power supply that used a crowbar circuit with an SCR to take out the fuse immediately in case of a short. I was monkeying with it because it was on a customer’s premises and I had a 12 hour wait to get a replacement. I decided to remove the crowbar, and the load, to see if I could troubleshoot the circuit. What I had not noticed was that the electrolytics were rated at 25 V and the open circuit voltage was 40 V. I didn’t find that out till I removed the load. You could have heard me swearing in Australia at the engineer who designed such a setup.
Very, very, luckily, the capacitor was oil filled with a vent. It blew up in my face, which nearly caused me heart-failure, since it was around midnight, and I lay there on the floor helplessly watching a tiny guyser of oil pour out of the vent. I could very easily have been blinded had it been paper filled, because I’ve seen them blow too and they’re like a firecracker..
Speaking of inexperienced engineers, I worked for one during a summer. He gave me a project of building a prototype from a diagram he had designed. The first thing I noticed was that the output transistors were reversed. Not wanting to immediately challenge authority in the guise of a graduate engineer, I asked him if they were meant to be that way. He asked how I thought they ‘should’ be, and I mentioned the collectors should go to a positive source since they were NPN. He contemplated for a minute and a light went on. He excused himself for a moment and came back with a pad of paper and a pencil, asking me to note any other problems I might notice. I filled a sheet of the pad.
On my first day of engineering at university, the dean addressed our class. He showed us slides of a power station he had blown apart due to placing the busbars too close together. People tend to think that university graduates are infallible, but they are far from it. Some, like a Feynman, are way ahead of the rest, but any Ph.D, is just as dumb as anyone else when you get him out of his comfort zone. That’s what I’m beginning to sense with climate science. It’s a relatively young discipline and I don’t think the basics have been well-corroborated with basic physics.
“BTW…according to Thieme, NASA no longer lists back-radiation in its energy budget diagram. I don’t know how they account for WV increases due to ACO2.”
That’s in their educational part for kids. It’s supposed to be a simplified diagram. If you look around, other documents refer to greenhouse gases.
My goodness.
Comment from: Jan Pompe April 8th, 2009 at 1:34 pm
Eric
” I can safely assume the scientists who study albedo take this all into account.”
Not in that paper that you posted the link to. You can’t use the peak angles where is is only for a short time you need also to take in diurnal variation and integrate it over the period. I’m not suggesting that you do it for my curiosity I can do that for my self but for your benefit.
“but it is not correct to consider the albedo of water 1 above the arctic circle as you have claimed in your initial post on this subject”
I agree I should have been more careful but there is a point that tracks the Sun on the other side of the Pole where not the Albedo (I don’t think I claimed that it was 1) but the angle of incidence made the reflectivity 1 I don’t think it is the same thing.
Think again. It is the same thing.
http://www.esr.org/outreach/glossary/albedo.html
Albedo: definition.
Albedo is the fraction of solar energy (shortwave radiation) reflected from the Earth back into space. It is a measure of the reflectivity of the earth’s surface. Ice, especially with snow on top of it, has a high albedo: most sunlight hitting the surface bounces back towards space. Water is much more absorbent and less reflective. So, if there is a lot of water, more solar radiation is absorbed by the ocean than when ice dominates.
Eric:
“when you claimed paradoxically that melting arctic ice has a cooling effect.”
Then i suggest you put some iced cubes in glass of water at room temperature and find out for your self if it warms the water up now that would be paradoxical.. The latent heat of fusion of water is 334 J/g that energy has to come from somewhere or do you think that it could melt without taking energy from the water it’s in?
Now kindly explain how it is paradoxical.”
You are confusing temperature with heat.
The heat used to melt the ice is not lost by the ocean, since the melted ice remains part of the ocean and the earth atmosphere system. The melting and freezing of Arctic ice is a cyclical phenomenon so no heat is gained or lost from the earth atmosphere system by this process. However the added heat absorbed from the sun by the ocean during the summer, would otherwise be lost to space by reflection.
The melting may lower the temperature of the ocean temporarily, but upon freezing in the winter, it gives heat back to the liquid part of the ocean and atmosphere. The ice formed on the surface of the ocean during the winter actually, helps the ocean retain heat, by acting as insulation. It keeps the top surface of the ice cooler than the ocean water, and reduces heat loss from the ocean by radiation.
Your concept that AGW is wrong is screwing up your ability to think clearly. This isn’t rocket science. Of course it isn’t electronics either.
Sorry for misplacement of italics in the above post.
The last 4 paragraphs are my words. i.e.:
You are confusing temperature with heat.
The heat used to melt the ice is not lost by the ocean, since the melted ice remains part of the ocean and the earth atmosphere system. The melting and freezing of Arctic ice is a cyclical phenomenon so no heat is gained or lost from the earth atmosphere system by this process. However the added heat absorbed from the sun by the ocean during the summer, would otherwise be lost to space by reflection.
The melting may lower the temperature of the ocean temporarily, but upon freezing in the winter, it gives heat back to the liquid part of the ocean and atmosphere. The ice formed on the surface of the ocean during the winter actually, helps the ocean retain heat, by acting as insulation. It keeps the top surface of the ice cooler than the ocean water, and reduces heat loss from the ocean by radiation.
Your concept that AGW is wrong is screwing up your ability to think clearly. This isn’t rocket science. Of course it isn’t electronics either.
A beaut little quote for Gordon on feedback , both stray and controlled
“Oscillation occurs when an amplifier is furnished with a feedback path that satisfies two conditions:
Amplitude Condition — The cascaded gain and loss through the amplifier / feedback network must be greater than unity!
Phase Condition — The frequency of oscillation will be at the point where loop phase shift totals 360 (or zero) degrees!”
http://sss-mag.com/cosc.html#theory
At one point I got pretty interested in spread spectrum techniques and CDMA on the practical side (See above link). Smacking a phased locked loop at RF with video was another thing I had to investigate. However I won’t do the calcs for any of it since it should all be accepted as natural enough in the electronics biz to just probe around and listen as opposed to touching with the stuff with your finger.
Like oscillators it becomes pure art in the end.
Comment from: Gordon Robertson April 8th, 2009 at 4:18 pm
SJT “Ice melts in the Arctic. The albedo changes is lower, because sea water is darker than ice, the earth absorbs me heat. The ice melts faster”.
You make it sound like you’re doing all this in a thimbleful of water. How about that Mother of Heatsinks surrounding the ice? We call them oceans up here. Even if what you say is true, how long is all this going to take and why haven’t we seen any of it yet?
You are an excellent at creating catchy rhetorical non sequitors and meaningless posts.
No argument is too foolish if it appears to you to debunk anything about AGW, even if it defies established physics.
Let us examine your statement to expose how stupid it is.
The amount of heat absorbed by the ocean is proportional to its area, so the area of the ocean has no bearing on the question. If you warm the surface of the ocean with the sun, since, warm water tends to stay on the surface, the mixing is limited.
Finally, no one is saying the full effect of the increase of exposure of dark ocean water in the Arctic, and its increased absorption of sunlight, is going to result in an large jump in ocean temperature. It is going to take time. We have seen an acceleration in the loss of summer ice in the past few years. The ocean warmup is slow but inexorable and is expected to be slower than the land warmup because of heat capacity, but it is a genuine feedback mechanism.
Jan,
Your Esnips paper is nonsense. There is no proof there that the analog you are using applies to the earth atmosphere system. You are just assuming it.
What you disdained as a high school physics demonstration is the proper analogy between electrical systems and thermal systems.
Flow of current is equivalent to flow of heat, and voltage difference is equivalent to temperature difference. This was used in the case of heating a house to give a perfectly good analogy between the thermal and electrical system. Increasing the resistance increased the inside temperature. If you have a resistive element which increased its resistance with increasing voltage, you would have amplification of the temperature difference if you added more insulation.
The sun is a heat current source and the earth’s atmosphere is a resistive element.
The earth is more complicated because it has different kinds of currents, varieties of heat flow, which have different parallel impedances, in addition to capacitors. It makes it difficult to prove the validity of any electrical analogy in such a complicated case.
Eric: “It makes it difficult to prove the validity of any electrical analogy in such a complicated case”.
Lets stretch our imagination further by looking for the tuned circuit
The more I frequent these web sites, the more I notice a certain pattern.
Many of the frequent posters are retired engineers, like me, who did something different from climate science for a living.
After years of working in engineering, one would think they would see the value of learning from experienced experts who are actively researching their fields, and would have a some respect for what it takes to think through a problem. Instead, they fall into the trap of using a little bit of knowledge that they have, into fooling themselves that they have the answers and the experts don’t understand what they are doing. What inevitably follows are posts full of unsupported assumptions, misstatements of physical principles like the first and second laws of thermodynamics etc. Then we get the anecdotes about incidents that happened during their careers.
I need to get a life.
“I need to get a life.”
It’s about that point that many visitory to this site disappear. No point bashing your head against a brick wall just because it feels good when you stop.
Eric
In that case increased reflectivity at high latitudes really should be taken into account and obviously they are not. You should not assume that they have it right or taken it into account unless you actually see it there in the calculations that is the meaning of due diligence.
Erix
Feel free to show that the atmosphere that the atmosphere is not thermally dissipative system. Feel free to show that heat can travel against the gradient. In other words prove it wrong.
Yes.
Yes and you think that is positive feedback it isn’t.
It is not I repeat not amplification because the constant current systems is an active feedback current control. You do NOT have that with sun.
Do you need a design? I have used it many times.
In normal passive dissipative system the current drops as you increase the load resistance. The derivation is there in section 5 where is the mistake?
You need a temperature difference to drive that flux what is it? Then provide us with a radiation heat transfer equation for that source and the surface. If you get it right you’ll see the system is dissipative. Then you can provide us with a radiation transport from surface to space. If you can’t convince yourself that the system is dissipative perhaps these will
http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F1520-0442(1997)010%3C0441%3ATOAGMS%3E2.0.CO%3B2
http://www.lpl.arizona.edu/~rlorenz/MEPRG.pdf
http://www.sussex.ac.uk/Users/jgd20/pubs/dyke_alergic_mepp.pdf
take note of the chart in the frame labelled “Maximising Entropy in Daisyworld”
compare that with my Fig 5
http://www.esnips.com/doc/1d10d862-46c8-4789-b38f-57110caac249/PassiveFeedback
and Miskolczi’s Fig 3
http://miskolczi.webs.com/2007.pdf
All the same except the first is a mirror image because diffusivity is the inverse of thermal resistivity.
Eric I need a week of sleep.
I forgot to mention that the feedback control in the the constant current source is negative if you change the load the feedback adjust the *voltage* to keep the current constant.
“I forgot to mention that the feedback control in the the constant current source is negative if you change the load the feedback adjust the *voltage* to keep the current constant.”
You just keep working on your electrical circuit models, I’ll just keep looking at the way it really works.
Obviously Will doesn’t think that the climate system is a dissipative system maybe this will help
http://www.sussex.ac.uk/Users/jgd20/lisbon2007/presentations/Kleidon%20Lisbon.pdf
“Feel free to show that the atmosphere that the atmosphere is not thermally dissipative system. Feel free to show that heat can travel against the gradient. In other words prove it wrong.”
No law of thermodynamics is broken, even if a certain amount of photons travel from the atmosphere back to earth, (when they are radiated in a random direction) the net energy transfer is from the earth to space. I’ll leave it as an exercise for you to create a model using electronic components, though I think it is a waste of time.
Will
Is it a dissipative system or not you can’t hit the goal posts even when they are standing still. Maybe you just think they move because your focus is so poor.
Eric,
I am not assuming the precipitation remains the same. I accept that a warmer climate will tend to produce more precipitation. Whether the amount of precipitation is going to eliminate the possibility of positive feedback is something that I don’t see as an obvious assumption. This answer to this question requires a lot of measurement and simulation.
The people who model this stuff say precipitation goes up, but calculate the positive feedback of WV doubles the temperature change due to CO2.
By the way do you think positive feedback is impossible, and melting arctic ice is cooling the earth also?
If you’re not assuming that precipitation stays the same, then your position is contradictory. More precipitation means more evaporation, given a constant average level of WV.
And no, I don’t think positive feedback is impossible. My point vis a vis WV feedback was that it will become *less* positive as the WV concentration increases.
In re: ice albedo feedback, I generally tend to accept that it will be a small positive feedback, but I have never run the numbers, so I could be convinced either way. I don’t really know.
Jan,
You have lost your marbles completely.
If the ice is freezing it is not because the atmosphere and the water are warmer than freezing but because they are colder than freezing, because the sun is not shining much, and they are losing heat, mostly by radiation to upper levels of the atmosphere and ultimately to space.
There is no perpetuum mobile of the second kind involved in this, and the heat of fusion is put into the surroundings of the ice as it forms.
I don’t know what you are trying to say with your links to papers about to the principle of maximum entropy production, which has the status of a hypothesis, not a proven physical principle governing the evolution of the earth atmosphere system.
The sun’s output of radiation impinges on the edge of the earth’s atmosphere regardless of what the earth’s atmosphere does to it subsequently. I call that a constant current source. Modification of the earth atmosphere system will change the subsequent path of the radiation that arrives. If you want to try modeling the behavior of the earth atmosphere system, under the action of this constant current source, as some kind of passive electrical network you are welcome to do so. OUter space would be the perfect current sink. The circuit elements would have to be modifiec as the system evolves to match what would be happening in the real earth atmosphere system. You have to prove that the electrical analogy you have created is the equivalent of the real physical system. You haven’t done that yet.
It is pretty clear that your thinking is muddled, and the desire to show AGW does not exist is creating all kinds of weird ideas in your brain.
Shawn wrote:
If you’re not assuming that precipitation stays the same, then your position is contradictory. More precipitation means more evaporation, given a constant average level of WV.
You are creating a false dichotomy. You are assuming that if it rains more, positive temperature feedback due to WV cannot happen. You have no physical principle to support your personal assumption.
More precipitation and evaporation, i.e. a higher turnover rate of water in the hydrological cycle, could increase the rate of heat transfer from the surface to the atmosphere. This may serve to limit the temperature rise due to positive feedback, but a priori, it is not necessarily going to make positive feedback go away. The GCM’s show more rain will occur, even while WV doubles the temperature increase due to CO2.
Even Lindzen and Spencer do not argue that it is obvious that positive feedback, due to WV, is not going to occur, based on the knowledge that it will rain more. As I understand it, their claim is that observations of clouds and some calculations that they make show that positive feedback is not happening.
Jan,
The ice melt an irreversible increase in entropy the heat is lost. The only way it can refreeze is to get rid of it to space over the winter it can’t send it to the water without a heat pump. Remember it is a dissipative system.
There may be an increase in entropy if you look at the water and ice as a closed system, but no heat is lost.
The point is that the earth is not a closed system. The sun is sending a constant flux of energy to the earth. The sun has a brightness temperature of 5800C. You can even use that energy to melt steel if you concentrate it, something you couldn’t do with the upwelling radiation from the earth’s surface.
The melting of the ice paves the way for more solar energy to be absorbed in the ocean, and remain in the earth atmosphere system rather than be directly reflected back into space during the Arctic summer. There is no entropy principle being violated here.
Eric, your argument is losing all consistency. You were originally arguing that you could have a higher ave. concentration of WV without a higher evaporation rate. This can only happen if precipitation stays the same. Since you claim to accept that there will be more precipitation, you must accept, then that there *is* more evaporation.
For the record, I *never* said that increased evaporation will eliminate positive feedback(assuming that feedback is currently positive), I claimed that more WV in the atmosphere will (on its own) tend to cool the surface and that such a cooling effect will become larger *relative* to the heating effect derived from the GH increase as the concentration of WV in the atmosphere increases.
Comment from: Shawn H April 9th, 2009 at 4:31 am
Shawn wrote,
Eric, your argument is losing all consistency. You were originally arguing that you could have a higher ave. concentration of WV without a higher evaporation rate. This can only happen if precipitation stays the same. Since you claim to accept that there will be more precipitation, you must accept, then that there *is* more evaporation.
I didn’t say it wouldn’t happen. I said there is no fundamental physical law that says that this would not happen. It depends on the properties of the evaporation rates. I also said that I would check to see what the models said and report back, which I did. There is more transpiration and it doesn’t prevent positive feedback according to the GCM’s.
For the record, I *never* said that increased evaporation will eliminate positive feedback(assuming that feedback is currently positive), I claimed that more WV in the atmosphere will (on its own) tend to cool the surface and that such a cooling effect will become larger *relative* to the heating effect derived from the GH increase as the concentration of WV in the atmosphere increases.
This presumably is not tied to the rate of transpiration and therefore related to the transport of heat from the surface to the upper troposphere by that mechanism when condensation occurs.
So you are saying there is an inverse greenhouse effect. More water vapor will cool the earth’s surface rather than preventing the escape of heat at a given temperature. Do you have a reference to a paper of any kind, preferably peer reviewed, not just some Joe Blogger, which describes this?
“Eric, your argument is losing all consistency”
Mate, IMO our Eric is easy enough to follow even for a Joe blogger like me and he writes straight from the heart of a topic not the fringe.
Eric: This presumably is not tied to the rate of transpiration and therefore related to the transport of heat from the surface to the upper troposphere by that mechanism when condensation occurs.
So you are saying there is an inverse greenhouse effect. More water vapor will cool the earth’s surface rather than preventing the escape of heat at a given temperature. Do you have a reference to a paper of any kind, preferably peer reviewed, not just some Joe Blogger, which describes this?
Eric, I don’t know why you are not getting this. Since the cooling effect is proportional to the amount of condensation/precipitation, of course it is tied to the rate of evaporation(transpiration).
As to a paper that references what I am talking about which part are you having a problem with? The fact that if condensation increases so must evaporation, the fact that GH effect increases logarithmically with the concentration of the gas, or heat that is emitted further from the ground will cool the surface more than heat that is emitted closer to the ground.
Mate, IMO our Eric is easy enough to follow even for a Joe blogger like me and he writes straight from the heart of a topic not the fringe.
Mate, whether Eric is easy to follow or not, he has been arguing contradictory things on this thread namely that the rate of evaporation will not increase and that the rate of precipitation will.
“Eric, I don’t know why you are not getting this. Since the cooling effect is proportional to the amount of condensation/precipitation, of course it is tied to the rate of evaporation(transpiration).”
But it only cools because it got warmer in the first place. There are limits to the AGW effect, but only after the temperature has gone up.
Eric
[emphasis mine]
I see your problem you don’t have a good handle on thermodynamics but that’s OK not many people do.
Entropy δS = δH/T
latent heat of fusion for water is 334J/g as the ice melts the temperature doesn’t change so all that heat is irreversibly converted to entropy it’s no longer heat so it is lost but not the energy. That icy cold melt water sinks and starts to make its way to the tropics where it will be a heat sink.
You have made two errors the first is that you are confusing heat and energy, the latter isn’t lost, but they are not the same and in physics these terms are defined exactly.
http://en.wikipedia.org/wiki/Heat#Thermal_energy
The second you are confusing “what must happen in a closed system” with “the system must be closed for this to happen”. The latter is not true small open systems can increase their entropy they can also decrease their entropy at a cost of increasing entropy elsewhere such that the total change is non-zero and positive (Clausius inequality).
http://hyperphysics.phy-astr.gsu.edu/Hbase/thermo/clausius.html
Wiki breaks it down a bit more.
http://en.wikipedia.org/wiki/Clausius_theorem
The only way that energy can be considered heat is if it can warm something colder and for the heat in the melt water and the Poles in general the next cold reservoir is space.
Shawn wrote:
For the record, I *never* said that increased evaporation will eliminate positive feedback(assuming that feedback is currently positive), I claimed that more WV in the atmosphere will (on its own) tend to cool the surface and that such a cooling effect will become larger *relative* to the heating effect derived from the GH increase as the concentration of WV in the atmosphere increases.
I still don’t really get what you mean by more WV in the atmosphere. Does more WV in the atmosphere mean a higher average concentration of water vapor, which is a consequence of the higher temperature which raises the concentration? If so what is the cooling effect of a higher average concentration on its own?
You didn’t really answer that question. Instead what you said was:
Eric, I don’t know why you are not getting this. Since the cooling effect is proportional to the amount of condensation/precipitation, of course it is tied to the rate of evaporation(transpiration).
So now it isn’t the higher average concentration on its own, it is the transpiration which creates the cooling effect.
What is ridiculous is you wonder why I am not getting this. Your thoughts are hardly a model of clarity.
So now I really don’t know what you think about this whole question.
Eric
Do you know what a perpetuum mobile is?
It’s this:
[emphasis mine]
Not this:
Did you deliberately make the change (i.e. left out giving heat back to liquid ocean) without acknowledging your error?
If you though I wouldn’t notice and draw attention to it the you sir with all due respect have lost our marbles;-)
Maximum entropy and minimum energy are pretty well established second law principles.
http://en.wikipedia.org/wiki/Principle_of_minimum_energy
and that the trajectory will take the quickest possible path is also a well established principle
http://en.wikipedia.org/wiki/Hamilton's_principle
It is actually a proven physical principle of the universe and existence. The hypothesis part is whether or not it’s useful in climate analysis. I have an open mind on that but what I don’t have an open mind on is that it’s a dissipative universe and part of that dissipation occurs in out atmosphere which as far as heat and energy is concerned is dissipative. Those papers show that most clearly.
Which brings us back to positive feedback which is not possible in passive dissipative systems.
You might well call it that but that would be a false analogy because a constant current system is especially for those of us who use them or have used them an active negative feedback controlled system. This the sun/atmosphere is not if the load impedance changes a constant current (or heat flux) source will through negative feedback increase the voltage (or temperature) to keep the current (or flux) constant you may have noticed it gets a little cooler when there are clouds about a constant source will not allow that to happen.
I am a bit confused, you
A you do not seem to understand what a dissipative system is or the difference between active and passive systems
B you don’t know the difference between positive and negative feedback (You have the constant current case back to front when you say it’s positive feedback).
C you intimated you are some sort of engineer
but while I am not an engineer I have spent all my life around engineers and more importantly worked with them, and mechanical, chemical and electrical engineers in my experience generally do not get confused about these things so what sort of engineer were you?
Jan Pompe wrote:
I see your problem you don’t have a good handle on thermodynamics but that’s OK not many people do.
Entropy δS = δH/T
latent heat of fusion for water is 334J/g as the ice melts the temperature doesn’t change so all that heat is irreversibly converted to entropy it’s no longer heat so it is lost but not the energy. That icy cold melt water sinks and starts to make its way to the tropics where it will be a heat sink.
Heat and entropy have different units, so heat cannot be converted into entropy.
As you say, some people don’t have a good handle on thermodynamics.
The ice and water together before the transition have the same amount of energy as they had before the transition, assuming that the energy to melt the ice came from the water. Since heat is the energy transferred from one object to another, the ice and water taken as a unit have not transferred any as a result of the ice melting, even though the entropy of the ice and water have increased as a result of the melting process.
The only way that energy can be considered heat is if it can warm something colder and for the heat in the melt water and the Poles in general the next cold reservoir is space.
Not so fast. In the winter time, the atmosphere can get colder than the water, because the sun goes down. The same water, even after the melted ice cools it down slightly can warm the atmosphere by convection, radiation or even in principle evaporation.
Your condescending statements seem quite foolish. Every attempt to correct what you consider my errors, has errors which render the statements invalid. You better slow down and think a little harder.
Eric
Oh boy Eric you really have no idea do you YES THEY DO HAVE DIFFERENT UNITS THE ARE NOT THE SAME that’s why its converted it’s a conceptual thing where .
Are you some sort of clown? I’ve already worked out you are dishonest the evidence in my post at the top of this page.
Yes Eric they have same energy please show where I said they don’t (I’m no longer assuming this is an honest mistake on your part).
Yes the entropy has increased and the heat has decreased gone in in fact and is to be found in that increased entropy the ice is no warmer and the water is colder. In fact simple arithmetic will tell you it takes 163 g of water to lose 1K to melt 1 gram of ice.
And I suppose it will take this heat it gains to the tropics!!! The next cold reservoir is space, the atmosphere is part of the transport system or the heat engine that transport the energy and the entropy. The three reservoirs that drive the atmospheric heat engine the tropical surface (including ocean) -> Polar surface + ocean -> space. Of course there is transport to space over the entire surface we shouldn’t ignore that.
you have yet to show that so far I have seen you
confuse heat and energy
positive and negative feedback
active and passive systems
and now the reservoirs with the transport between them
I should think that’s all pretty foolish.
“you have yet to show that so far I have seen you
confuse heat and energy
positive and negative feedback
active and passive systems
and now the reservoirs with the transport between them
I should think that’s all pretty foolish.”
In your own mind…..you win again.
Gavin
It’s not that difficult Gavin we have ~ 170 W/m^2 coming into the surface but ~320W/m^2 doing the rounds between air and surface something in electronics that behaves like that is the tank tuned circuit it has much larger currents (Unloaded of course) circulating than the voltage across it would allow. Is it a tuned circuit? Absolutely the wavelengths of the fluxes in the back radiation and thus circulating are the ones resonant with absorbing species. There fore there is not just one tuned circuit but several involved.
Owzat?
Will by all means feel free to show
* that thermal energy and heat are the same thing
* the constant current source is positive feedback (I can guarantee it isn’t)
* the earth’s system is an active one that has an arbitrary power source to draw on
* the earths system is not dissipative
* the heat reservoir and the transport system are the same thing.
just for a change lets have something substantive from you instead of the usual peanut gallery type comments.
Eric Adler “…they fall into the trap of using a little bit of knowledge that they have, into fooling themselves that they have the answers and the experts don’t understand what they are doing. What inevitably follows are posts full of unsupported assumptions, misstatements of physical principles like the first and second laws of thermodynamics etc.”
Actually, the process is far more complicated. Having studied some science at a university level, and having seen solutions to problems that I could not see at first, I am acutely aware of rushing to assumptions. Very little of what I post is based on my own experience or knowledge. I study papers like those of G&T and try to apply my own understanding to their work. If that’s not forthcoming, I try to corroborate what they say with the work of other scientists. I don’t accept the AGW theory because it seems intuitively wrong and the physical data collected from the atmosphere as well as the atmosphere’s response to CO2 increasing supports my intuition.
Anything I have posted is put out there to be debated or flamed, whatever the readers may feel. I am hoping for intelligent discussion and getting very little of it. I am also dismayed with the licence being taken with basic physics. It’s not overly complicated on the face of it, but climate scientist who should know better are ignoring the very obvious. It amazes me that people are actually willing to take the word of a Ph. D just because he is one. There are astrophysicists out their who are convinced time exists and they are completely lacking in the awareness to see it is an illusion. Having a degree does not immunize a person agaisnt stupidity.
In climate science, that translates to scientists trying to turn gases that makes up about 1% of the atmosphere into a blanket that traps enough surface radiation to raise the atmospheric temperature 33 C, as the GHE suggests. You don’t need the 2nd Law to be suspicious of that enigma. However, if you’re going to apply it, you need to apply it to the movement of energy as heat, not the movement of energy per se. You just can’t add energies because they have a certain sign without considering their source and how they are acting.
I don’t know which experts you’re talking about in your statement above. You seem to have something in mind but you’re keeping it a secret. I have read Lindzen, Spencer, Christy, Michaels and Akasofu, who are all experts in their own right, yet they are all saying different things. If you’re talking about IPCC experts, I have no respect whatsoever for scientists who hide behind such a political umbrella. I have always had a problem with smug, gutless people.
Gavin Schmidt was exposed by Jeffrey Glassman, Rahmstorf was exposed by Lindzen and G&T, and Trenberth was exposed by Chris Landsea. Michael Mann was destroyed by McIntyre and McKitrick, as well as the statistician Wegman and the NIS. I’m seeing a lot of scientists and pseudo-scientists who are out of control and practicing bad science. Why the heck should I respect them? One of the worst in IMHO is Stephen Schneider, who alleged it’s OK to lie to get a consensus across, and to ignore real data in lieu of model output. Are they all losing it?
Many climate scientists, especially modelers, are creating a jargon that has no scientific basis. For example, what is a forcing? There’s no such thing in physics, it’s a term peculiar to differential equations and modeling. I wont use the term because it obfuscates the reality and muddies the physics. In the same way, feedback is being applied wrongly. Lindzen and Spencer have both tried to point that out and they are ignored.
Your use of entropy gives me a hint as to your discomfort with thermodynamics. You don’t need to use entropy in a discussion of heat flow unless you are interested in free energy. That is more a topic for physical chemistry, along with enthalpy. Although I think it’s folly to derive any heat equations or heat interactions in the atmosphere other than for theory, I don’t see why entropy has to be discussed at all. We’re not talking about a heat engine, we’re talking about poorly understood phenomena.
All I’m trying to do is be the Devil’s Advocate. I don’t have the expertise to say for sure what’s going on in the atmosphere, but the simple fact that someone at my level can see inconsistencies in the theories doesn’t say much for their validity.
The most important part of posting, however, and thanks to Jennifer for supplying the medium, is to rebutt the unadulterated nonsense being spewed by sites like realclimate. It’s important to get the skeptical viewpoint out even if is lacking expertise at times. Having said that, I’m impressed with some of the science discussed here. Methinks thou doth protest too much and lacketh a sense of humour.
Are you sure you’re an engineer? Whatever happened to:
We are, we are, we are the engineers,
We can, we can, demolish forty beers,
Drink rum, drink rum, drink rum and follow us,
For we don’t give a damn for any old man who don’t give a damn for us.
Or…
Godiva was a lady who through Coventry did ride,
To show the local villagers her lovely bare, white hide,
The most observant fellow there, an engineer of course,
Was the only one who noticed that Godiva rode a horse.
Here’s one for Louis:
She said, “I’ve come a long, long way, and I will go as far,
With the man who takes me from this horse and leads me to a bar,
The man who took her from her steed and lead her to a beer,
Was a bleary-eyed geologist, and one helluva an engineer.
Jan “so all that heat is irreversibly converted to entropy”
This is just bizarre. Eric shows a perfectly good understanding of thermodynamics. The above statement is wrong in so many ways.
Heat is never “converted to entropy”. Eric’s observation that they have different units is a sufficient objection, but often in heat transfer situations, heat is not changed at all, yet entropy increases. If an insulated rod with a hot and cold end comes to a uniform temperature by conduction, heat is conserved, but entropy increases.
Eric Adler “Let us examine your statement to expose how stupid it is”.
yeah…lets do that exactly. If you have ice in a thimble, in a room at 20 C, it’s going to melt very quickly. If you have it immersed in water near 0 C, it will hardly melt at all, nor will the temperature of the ocean. Then comes winter. The melting in the arctic is happening in the summer and it’s likely due to wind and ocean currents related to the AMO.
You’re responses concern me. You have no understanding of feedback theory and you seem to have no idea about thermodynamics. Where is the heat coming from to melt Arctic ice? Solar radiation is highly reflected and even though the oceans in the Arctic represent a darker mass, the solar radiation up there is correspondingly low. With all that ice in the Arctic ocean, it will be a long time before you can swim there, even in summer.
You claim that I am willing to use rhetoric to discredit AGW, but it seems to me you’ll do more to defend that crippled theory. You have spent days arguing with Jan about feedback and it’s obvious to me you have no idea what your talking about nor do you have an interest in learning. You even argue about constant current sources, claiming the Sun represents one, when you have no idea what a CCS is, let alone a current.
I’ll take your ad homs with a pinch of salt since it’s the typical modus operandi for the AGW crowd.
If you have it immersed in water near 0 C, it will hardly melt at all, nor will the temperature of the ocean.
should read
If you have it immersed in water near 0 C, it will hardly melt at all, nor will the temperature of the ocean change quickly.
Jan wrote:
Did you deliberately make the change (i.e. left out giving heat back to liquid ocean) without acknowledging your error?
If you though I wouldn’t notice and draw attention to it the you sir with all due respect have lost our marbles;-)
I plead guilty to vanity. I realized I had made an error, and modified my position without calling attention to it, out of vanity, a quality that almost all humans possess.
In my defense, I have the objectivity, intelligence, and sufficient humility, to examine my own statements, and recognize when I have made an error.
Nick when are you going to come clean that you are not, never have been and never will be a physicist.
When are you going to learn that heat and energy are not the same? Energy is conserved heat is not.
http://en.wikipedia.org/wiki/Heat#Thermal_energy
How many times does that need to posted before it finally sinks in? The heat flow through a boundary (eg from water to melting ice) is quantified by the increase in entropy ie δQ = δST. I really don’t care much that you or Eric don’t think “convert” is the right word to use but never the less the heat transferred is the entropy multiplied by the temperature. You have to get it straight heat is not the energy in the water nor it the energy in the ice or the melt water after the ice has melted it is the energy crossing the water/ice boundary as it is crossing the boundary.
Now what are the units of that energetic entity crossing the multiplied by the temperature to give a measure of the actual change of thermal energy without raising it’s temperature? It wouldn’t be the same as entropy now or would it?
Eric
Not all humans I know many who have had such little self esteem they .. well they are no longer with us. A little vanity is probably a necessary trait. I would however have been better to own up before being called on it. Like I am going to now. I don’t know what I was thinking when I agree with you that heat does not have the same units as entropy when in fact it does.
Heat is energy transferred or more accurately energy transferring or passing through a thermodynamic boundary like between water and ice (for Nicks example of the rod a physicist would use and imaginary one or perhaps an infinite number of imaginary ones) this is quantified by the temperature (preferable the one that remains constant) by the increase in entropy.
http://en.wikipedia.org/wiki/Heat#Entropy
It’s not an easy concept to get the head around expecially if you’ve used heat conversationally as the quality the something hot has so you think of it as energy but in physics we don’t need another word for energy we already have “energy” we might qualify it with adjectives like thermal, electromagnetic or mechanical and they all have the same units. So “heat” is retained for energy transferring in much the same way current is reserved for charge transferring. I hope this clears it up.
Jan When are you going to learn that heat and energy are not the same?
I meant exactly what I said, and it is correct. In this case, heat is conserved. In other cases it might have been converted to other forms of energy, but here it is not, so its conservation follows from the law of conservation of energy. No heat is lost, but entropy increases.
Jan Pompe wrote:
Maximum entropy and minimum energy are pretty well established second law principles.
http://en.wikipedia.org/wiki/Principle_of_minimum_energy
and that the trajectory will take the quickest possible path is also a well established principle
http://en.wikipedia.org/wiki/Hamilton’s_principle
You certainly do use man links to support your ideas. The problem seems to be that you don’t read them to be sure they are applicable to the problem under discussion.
The Maximum entropy etc. apply only to closed systems. The earth atmosphere system is not one. You haven’t made clear how this applies to the question of whether increased average WV concentration provides positive feedback to a surface temperature increase.
Your Hamilton’s principle link is a joke. Here is what it says:
Wikipedia does not have an article with this exact name. Please search for Hamilton’s principle in Wikipedia to check for alternative titles or spellings.
Why don’t you slow down and use your brain to really think, instead of using your fingers to type.
Jan Pompe,
Not all humans I know many who have had such little self esteem they .. well they are no longer with us. A little vanity is probably a necessary trait. I would however have been better to own up before being called on it. Like I am going to now. I don’t know what I was thinking when I agree with you that heat does not have the same units as entropy when in fact it does.
Heat is energy transferred or more accurately energy transferring or passing through a thermodynamic boundary like between water and ice (for Nicks example of the rod a physicist would use and imaginary one or perhaps an infinite number of imaginary ones) this is quantified by the temperature (preferable the one that remains constant) by the increase in entropy.
http://en.wikipedia.org/wiki/Heat#Entropy
It’s not an easy concept to get the head around expecially if you’ve used heat conversationally as the quality the something hot has so you think of it as energy but in physics we don’t need another word for energy we already have “energy” we might qualify it with adjectives like thermal, electromagnetic or mechanical and they all have the same units. So “heat” is retained for energy transferring in much the same way current is reserved for charge transferring. I hope this clears it up.
The longer we have this discussion, the more tangents you go on and the more agitated and confused you get. The units of entropy are :
Joules x Deg K
It is possible to have a change in entropy without the passage of any heat. Simply take a flask of N2 and a flask of O2 and connect them together and let the gases mix.
Entropy and heat are different things and have a totally different character.
Nick
Well of course you meant what you said but that does not mean it’s correct. Heat is energy being transferred when there is no energy transferring there is NO heat so how can it be conserved? I agree the energy that enters into the ice is conserved but that is NOT heat. No energy is lost but there is no increase in temperature. The entropy goes up by the exact amount of the energy being transferred divided by the temperature which in the case of melting ice does not go up so all the heat being transferred or passing through the water/ice boundary and has the same units as the entropy is ending up as entropy.
So Nick when are you going to learn than thermal energy and heat are not the same?
We had these guys Like Clausius, Carnot, Pascal & Fourier to name a few work out all these terms and relations for us as well as how they sat together we don’t need you to redefine them for us to suit yourself.
Jan,
I said nothing about ice in that case. My statement was as you quoted it:
“If an insulated rod with a hot and cold end comes to a uniform temperature by conduction, heat is conserved, but entropy increases.”
Do you think that the heat in an insulated rod left to come to a uniform temperature does change? Or is this all just pointless bluster?
Comment from: Gordon Robertson April 9th, 2009 at 7:17 pm
Eric Adler “Let us examine your statement to expose how stupid it is”.
yeah…lets do that exactly. If you have ice in a thimble, in a room at 20 C, it’s going to melt very quickly. If you have it immersed in water near 0 C, it will hardly melt at all, nor will the temperature of the ocean change quickly. Then comes winter. The melting in the arctic is happening in the summer and it’s likely due to wind and ocean currents related to the AMO.
Now you are changing your statement. The original statement that I attacked was:
You make it sound like you’re doing all this in a thimbleful of water. How about that Mother of Heatsinks surrounding the ice? We call them oceans up here. Even if what you say is true, how long is all this going to take and why haven’t we seen any of it yet?
To recap what I said.
It is pretty well agreed by oceanographers that the major influence in the melting of ice is warm ocean water. The warmest ocean water is near the surface.
We have seen the summer ice extent area decline over the past 30 years and the decline is accelerating.
You’re responses concern me. You have no understanding of feedback theory and you seem to have no idea about thermodynamics. Where is the heat coming from to melt Arctic ice? Solar radiation is highly reflected and even though the oceans in the Arctic represent a darker mass, the solar radiation up there is correspondingly low. With all that ice in the Arctic ocean, it will be a long time before you can swim there, even in summer.
Shipping companies now making plans to use the NW passage for commercial shipping, and nations bordering the Arctic are suddenly ramping up to exploit the undersea oil in the arctic ocean because they expect the summer ice to be gone soon. It is true that they aren’t planning to build any beach resorts there, but what kind of a dumbass argument is that anyway?
You claim that I am willing to use rhetoric to discredit AGW, but it seems to me you’ll do more to defend that crippled theory. You have spent days arguing with Jan about feedback and it’s obvious to me you have no idea what your talking about nor do you have an interest in learning. You even argue about constant current sources, claiming the Sun represents one, when you have no idea what a CCS is, let alone a current.
AGW is hardly a crippled theory, when 97% of active researchers in climatology support it, and the world’s political leaders are trying to figure out what action to take to reduce it or deal with it.
I’ll take your ad homs with a pinch of salt since it’s the typical modus operandi for the AGW crowd.
Too much salt is not good for your blood pressure.
Eric:So now it isn’t the higher average concentration on its own, it is the transpiration which creates the cooling effect.
What is ridiculous is you wonder why I am not getting this. Your thoughts are hardly a model of clarity.
So now I really don’t know what you think about this whole question.
Ok, I can see that my use of “on its own” was confusing to you(I meant it in the context of treating it separately from any heating GH effect). However, it is pretty clear (and I thought that we had already agreed) that higher average WV yields a higher precipitation rate. Thus, when I say that ave WV is higher I am *also* saying that the rate of evaporation is also higher. Given that I think that higher average WV yields higher precipitation, there is no way the rate of evaporation *can’t* be higher. Clear enough?
Comment from: Shawn H April 10th, 2009 at 1:07 am
Ok, I can see that my use of “on its own” was confusing to you(I meant it in the context of treating it separately from any heating GH effect). However, it is pretty clear (and I thought that we had already agreed) that higher average WV yields a higher precipitation rate. Thus, when I say that ave WV is higher I am *also* saying that the rate of evaporation is also higher. Given that I think that higher average WV yields higher precipitation, there is no way the rate of evaporation *can’t* be higher. Clear enough?
I agree and we can continue the discussion.
The next question, iabout positive feedback due to WV, is do other effects that would go along with the increased concentration of WV, such as an enhanced transpiration rate prevent the appearance of positive feedback? I believe this is a quantitative question with no obvious answer. You claimed that you could calculate in your head that positive feedback couldn’t happen. On the other hand, as I documented in a previous post, the GCM’s get both positive feedback due to WV and an enhanced transpiration rate.
Eric
I didn’t check whether the article had it all wikipedia is generally pretty good on terminology like that :- mea culpa. I’ll see what I can find, but not tonight and only if you really are interested.
I am neither agitated nor confused
You just keep coming out with more nonsense to prove that positive feedback in passive dissipative system is possible but you keep failing. Yes every new thing you try creates another tangent because it shows up another thing that you don’t quite understand as well as you think you do.
Would you like another list? I had no idea I was shooting so far over you head.
I was surprised to see you using a mixture of O2 and N2 as demonstration of entropy increase in Joules/Kelvin. Do I need to go on yet another tangent to explain the difference between thermodynamic entropy and von Neumann entropy or entropy of mixtures or Shannon’s entropy the latter have more to do with your example and I can assure the units are not Joules/Kelvin and have nothing to do with heat. I would have thought that was obvious. (by the way absolute temperature units are just ‘Kelvin’).
Now if you wish to stay on the issue of positive feedback you really need to show that it is possible that a passive dissipative system can have gain. I have shown in terms of signal flow how you can’t send a signal from the output back back to the summing junction (in climate case the surface) in a system described by this equation that you introduced Eo/Ei = A(1-BA) because the potential (or temperature) is higher than the output because of the dissipation in the system and it requires an auxiliary power source to make the losses up.
The block diagrams do not necessarily represent electrical system it can be any system controllable with feedback e.g. ecological with negative feedback due to predation etc.
On the other hand you might show that the atmosphere is not dissipative (it will be difficult as it clearly is) or that there is an alternate power source to make up the thermal losses in the system. I knocked that article up for an atmospheric physicist he seemed satisfied with it. I’m not sure what he’ll do with it. I added some bits and pieces over time, including the derivation of the maximum power theorem a few days ago. I’m perfectly happy to make clarifying improvements if you are will to make constructive suggestions.
Eric, you’re not listening. I never said that I don’t think positive feedback is possible(I agreed that it was possible) what I said was that whether or not it was currently positive, it will become less positive(or more negative if you prefer) as WV concentration increases. The cooling effect of increased evaporation/WV concentration will increase linearly with concentration while the GH heating effect from additional WV concentration which will only increase logarithmically.
Jan Pompe said,
Now if you wish to stay on the issue of positive feedback you really need to show that it is possible that a passive dissipative system can have gain. I have shown in terms of signal flow how you can’t send a signal from the output back back to the summing junction (in climate case the surface) in a system described by this equation that you introduced Eo/Ei = A(1-BA) because the potential (or temperature) is higher than the output because of the dissipation in the system and it requires an auxiliary power source to make the losses up.
You haven’t shown that a circuit with characteristics such as you have used for your proof represents the climate system. There is no way your current variable can reflect the mix of different colors of radiation and variation in their propogation characteristics, as well as the phenomena of convection and transpiration etc. The sun is also a fixed source of heat flow via radiation, so it is an ideal current source.
Jan Pompe wrote:
I was surprised to see you using a mixture of O2 and N2 as demonstration of entropy increase in Joules/Kelvin. Do I need to go on yet another tangent to explain the difference between thermodynamic entropy and von Neumann entropy or entropy of mixtures or Shannon’s entropy the latter have more to do with your example and I can assure the units are not Joules/Kelvin and have nothing to do with heat. I would have thought that was obvious. (by the way absolute temperature units are just ‘Kelvin’).
I was always under the impression that this was a real entropy. I don’t think this is wrong.
I am not the only one who thinks so:
http://en.wikipedia.org/wiki/Entropy_of_mixing#cite_note-3
In a paper on this topic[4], R. G. Keesing notes:
It is often implied that the mixing of two perfect gases leads to an increase in entropy. However when two perfect gases, in thermal equilibrium, mix there is no increase in entropy solely as a result of their mixing. The entropy increase on mixing through mutual diffusion is solely the result of the two individual gases occupying larger volumes and is the same whether or not the gases have mixed. The increase in entropy comes about because each gas absorbs heat in the process of isothermal expansion which is the same whether or not the gases have mixed. Thus the idea that increases in entropy, in non-interacting systems, is somehow connected with the mixing process is false.
Comment from: Shawn H April 10th, 2009 at 2:27 am
Eric, you’re not listening. I never said that I don’t think positive feedback is possible(I agreed that it was possible) what I said was that whether or not it was currently positive, it will become less positive(or more negative if you prefer) as WV concentration increases. The cooling effect of increased evaporation/WV concentration will increase linearly with concentration while the GH heating effect from additional WV concentration which will only increase logarithmically.
I was under the impression that you were claiming that this automatically makes positive feedback impossible. My apologies.
Jan,
One more point about you proof of impossibility.
I don’t believe the feedback signal in the climate system originates from the output.
It arises from conditions in the interior of the atmosphere and at the earth’s surface.
I don’t know where in your circuit these locations are represented, but the output voltage is not what is fed back.
I have not read of any research climatologist who believes that positive feedback is impossible.
There are some who say it is small, or not happening because of certain processes in the climate system are causing negative feedback etc. You seem to me to be out on a limb by yourself.
I certainly have not read everything, and mainly stick to the main stream stuff, and generally avoid reading stuff by Joe Blogger AGW denier, unless I feel a need to comment.
“Now if you wish to stay on the issue of positive feedback you really need to show that it is possible that a passive dissipative system can have gain”
Jan, when you finally lighten up I’m sure you will shine through like a big black button. While we are stuck on electrical circuits for analogies we must consider resonance in tuned passive circuits, cavities etc in terms of feedback then get round to realizing their limitations too as climate models.
While looking at photos of skies on my screen saver I’m reminded regularly that none of the physics expanded here represent my world and its atmosphere in its entirety. Since most of these personal pics have a cloudless background one in particular; a windswept collection of vapour trails taken long after the passage of the various aircraft on route from Melbourne to Sydney points to the lack of water vapour in our part of the world at any altitude.
By contrast; a recent series taken in Fiordland NZ shows complete atmospheric saturation in colourless shades of grey around sea level, a condition that can last for days despite the hordes of tourists.
I say any model of atmospheric WV must start with thin slices and calculus that build up from these extremes. Feedback in the later example needs to include all those hapless normally dry skinned souls with a thoroughly wet tail. ‘Weather’ we like it or not we are all part of the equation.
Eric
Then it isn’t feedback. The equation Eo = EiA/1-AB that you posted describes feedback where the source is from the output in a system as described by those block diagrams
“In a paper on this topic[4], R. G. Keesing notes:
It is often implied that the mixing of two perfect gases leads to an increase in entropy. However when two perfect gases, in thermal equilibrium, mix there is no increase in entropy solely as a result of their mixing. The entropy increase on mixing through mutual diffusion is solely the result of the two individual gases occupying larger volumes and is the same whether or not the gases have mixed. The increase in entropy comes about because each gas absorbs heat in the process of isothermal expansion which is the same whether or not the gases have mixed. Thus the idea that increases in entropy, in non-interacting systems, is somehow connected with the mixing process is false.”
Which is a pointless digression from the topic, but typically the result of debating Jan. Moving goal posts is his second most popular past time.
Eric After seeing you admission of bias i wasn’t going to worry about this because apart from your bias there is something interesting in it to investigate. I’ll keep that to myself for now.
No doubt the statistical mechanical and the entropy of uncertainty or Shannon Entropy have the same probability functions
S = Sum{ pj(ln(pj))} which is actually dimensionless multiplied by a conversion factor that has the units of the sort of entropy we are dealing with for example the Boltzmann constant has units JK^-1 same as thermal entropy where pj are thermal micro-states. For Shannon entropy the units might be ‘bits’.
So δS = δQ/T does not apply which it will do if the gases are a different temperatures to begin with because there will be a net heat flow through the boundary between the flasks.
There is no reason to use the Boltzmann constant because the mixing isn’t thermal and the uncertainty change is in positional information. I find it interesting because it really is the subject of on going debate like Maxwell’s daemon where incidentally it takes the invention of an impossible entity that does work without using energy to violate the second law. In this case it’s the hypothetical detection of the undetectable to make a case for increase in thermal entropy when identical gases mix.
These guys go into it in some detail and avoid using Boltzmann’s constant keeping their entropy study essentially dimensionless altogether.
http://arxiv.org/pdf/quant-ph/0401021v2
an no I haven’t got my head around it all yet.
Eric Adler “AGW is hardly a crippled theory, when 97% of active researchers in climatology support it…”
Given that the 97% is a figure from your vivid imagination, the AGW theory is crippled because it is based on computer model theory while ignoring observed climate sensitivity and the real data from satellites. Anyone with half a brain, which excludes 97% of AGW advocates, who would settle for a 1/4 brain, can see that the atmosphere has not responded to CO2 as predicted by models. Even Hansen had to back off in 1998, ten years after his model predicted 3 times the warming that occured. Another 10 years down the road, the warming is going in the wrong direction.
Also, the satellite coverage makes it clear that the warming is not global, with at least half the Earth having either not warmed or cooled. So, the term AGW is 1/3 wrong to begin with. We can dismiss another third by observing that the anthropogenic part represents a gas that is 3% of the atmospheric density of total CO2, which is only 0.04% of the atmosphere. How 3% of such a rare gas could possible affect any kind of warming is the issue. I would conclude, then, that a theory missing 2/3ds of it’s components is indeed crippled.
That leaves the warming part. As Akasofu pointed out, the IPCC failed to account for warming over the past couple of hundred year due to recovery from the LIA. When the estimated warming is subtracted, what is left could be claimed to be an error. There you have it, a piddly anthropogenic content, no globality, and questionable warming. I’ll have to revise my conjecture: AGW is no longer crippled, it is dead.
Gordon While thinking about model simulations you might be interested in a digital model of an analogue simulation; then we might discuss growing some warts on top of warts. 😉
http://landshape.org/enm/jan-pompe-science-project/
Jan Pompe…the stuff you’re doing with QUCS is interesting, and thanks for the link to it. Several posters have been baffled by your attempts but maybe we should explain to them how an integrator and differentiator are implemented with analog electronics. Many people are hung up on differentiation and integration as purely mathematical formulae,and once again, have no understanding that math is a reflection of nature, not a creator of it.
For example (feel free to correct me if I’m wrong…it’s been a long time since university), the standard parabola, with formula y = x.x (x squared) simply tells us that a parabola is a set of points on the x – y domain for which the rule y = x.x applies.
http://en.wikipedia.org/wiki/Parabola
So, for every value of x on the x- axis, there is a unique value of y. That creates a graph that is symmetrical about the y – axis because negative x’s squared are positive and correspond to the equivalent positive x-value, only on the negative side of y = 0. The parabola is the connection of all the points corresponding to x values. BTW…you can reverse the x and y to get a parabola lying on it’s side.
If the parabola is inverted, so it’s hump is sitting above the x – axis with it’s sides pointing down, and a person wants the area under the curve between the parabola and the x- axis, that person can estimate the area by building rectangles inside the curve with height y and width x. The areas of the rectangles are then summed. By making the width smaller and smaller, the number of rectangles increase and the number of rectangles become larger, fitting inside the curve better.
See first graph down on right hand side, and subsequent graphs:
http://en.wikipedia.org/wiki/Integral
In the limit (oooh, there’s that word again), the rectangles become so small that the width essentially disappears and the number of rectangles fit perfectly inside the curve. Then it’s a matter of summing the teeny rectangles to get the exact area between the curve and the x-axis. Those teensy rectangles are called differentials and the process of breaking the area into them is called differentiation. The reverse process, of summing the differentials, is called integration.
Electronic devices can emulate that integration and differentiation, in fact, the circuits that do that are called integrators and differentiators. The integrator takes differential pulses and converts them to an analog voltage, whereas the differentiator takes an analog voltage and converts it to a series of pulses. The pulse-width modulation refered to by Jan in the link is simply pulses with width that correspond to a certain analog voltage.
An example of each is shown halfway down the page:
http://en.wikipedia.org/wiki/Operational_amplifier_applications#Integrator
The models used in computer modelling are no different. They simply use digital codes that correspond to the ASCII format, which takes the alphanumeric set and converts it to digital codes. The climate models program differential equations into the computer, but all the functions, like sine and cosine functions, are computed the old way, by a series of additions and subtractions. They are very fast these days since they use a separate processor (math co-processor) that is dedicated to solving math functions.
I don’t think most people understand the problems involved. First of all, the modeler has to know how the atmosphere works, which is not possible at this time. Secondly, they are not modeling the atmosphere as it is, they are recreating it using formulae for gases, etc. that came from laboratories. In other words, they are synthesizing a virtual atmosphere based on their understanding of the atmosphere (which appears to be incomplete…by a long shot). Thirdly, there simply is not enough computing power to get the resolution required (the area on the surface with vertical altitude), and even if it was available, it would be virtually impossible for a team to coordinate their efforts with enough accuracy to do the atmosphere justice.
What surprises me so much is their insistence that the models are accurate. They are not. The model results are fudged heavily with concepts such as aerosol cooling.
WRT to Jan’s analogs, they are as acceptable as computer modeling. The models are using electronic devices to do their computing. I don’t see the difference between a person hardwiring electronic devices using thought, or someone programming electronic devices using thought. Each person is using thought processes to emualte a natural phenomena. At least Jan admits the difficulty in doing that.
The modelers are not observing the atmosphere directly, or working with it directly. They are working in their own minds, creating analogs of what is going on in the atmosphere. Since, many of them, like Gavin Schmidt, are mathematicians, they are getting confused over the actuality of the atmosphere. Most of the theory in the AGW paradigm, and the modeling, are nothing more than thought experiments. A person doing that in his living room would do it for fun. In their arrogance, the modelers are passing it off not only as science, but state-of-the-art science.
Gordon
There is a huge difference in cost once we go over certain (currently incalculable for lack of info) threshold for example imagine setting one up to simulate climate over a 500 km square area divided up into 5km square grid considering it’s going to have to be purpose built.
Give it a couple of integrators, multipliers, log and anti-log functions each then there is logistics of weighted coupling and averaging (integrating) it all. Might run blindingly fast but it will take a while to put it all together if you can find the space to do it;-).
Conceptually though there is no difference between qucs (or spice) where the engineer has to put together circuit to be simulated and set the parameters in the edit window and Planet Simulator where you feed a program the parameters you want for your simulation and the program puts together the “circuit” to be simulated The math for similarly behaving elements is the same. There are however bound to be some differences in the actual numerical methods employed. BTW Planet Simulator runs quite nicely on my Mac and Powerbook but it won’t compile the simulator on the linux (Ubutnu) laptop I haven’t investigated why yet and it will be a while before I bother.
“Eric After seeing you admission of bias i wasn’t going to worry about this because apart from your bias there is something interesting in it to investigate. I’ll keep that to myself for now.”
He didn’t make any admission of bias, IIRC, he just acknolwedged a simple mistake. Eric’s strike ratio is still about 99%, your’s is about 40%.
Will
As if you’d know.
“As if you’d know.”
Jan, you’re a joke. Anytime you are cornered, it’s off to circuits which can’t model the climate.
Will
I haven’t been cornered by anyone here and you show by this last statement you have been and still are totally clueless about this discussion and have never got beyond the point of sniping with valueless remarks.
The issue has been feedback Eric introduced this equation Eo = AEi/1-AB) that is Eric not me and that equation has been lifted straight out of feedback amplifier theory. I have shown it doesn’t even hold for a simple dissipative electrical system let alone a dissipative climate system. If you have a problem with that equation and the example of what it really represents then I suggest you take it up with Eric.
You have been shown a simple example of positive feedback, the change in albedo. Just because you can’t model it with an electrical circuit, you decide it can’t exist in the real world.
Will
That was Eric’s escape, which if you actually do the sums is neither feedback nor positive, from the fact that this equation of his
Eo=AEi/(1-AB), having been lifted from amplifier theory, doesn’t fit the bill for water vapour feedback.
It’s a positive feedback, no matter what circuits you come up with.
Will
Circuits? Will what on earth are you on about? It’s optics mostly. Haven’t you worked out yet that there ice there because it’s cold in turn because most of the sun light goes sailing past if it gets there at all, and not the other way around?
Comment from: Gordon Robertson April 10th, 2009 at 3:25 pm
Eric Adler “AGW is hardly a crippled theory, when 97% of active researchers in climatology support it…”
Given that the 97% is a figure from your vivid imagination, the AGW theory is crippled because it is based on computer model theory while ignoring observed climate sensitivity and the real data from satellites. Anyone with half a brain, which excludes 97% of AGW advocates, who would settle for a 1/4 brain, can see that the atmosphere has not responded to CO2 as predicted by models. Even Hansen had to back off in 1998, ten years after his model predicted 3 times the warming that occured. Another 10 years down the road, the warming is going in the wrong direction.
http://climatesci.org/2008/02/22/is-there-agreement-amongst-climate-scientists-on-the-ipcc-ar4-wg1/
http://www.climatesci.org/publications/pdf/Brown.pdf
4. Almost all respondents (at least 97%) conclude that the human addition of CO2 into the atmosphere is an important component of the climate system and has contributed to some extent in recent observed global average warming.
There is another, different poll that I have found that shows the same percentage. So it is not my imagination.
Also, the satellite coverage makes it clear that the warming is not global, with at least half the Earth having either not warmed or cooled. So, the term AGW is 1/3 wrong to begin with. We can dismiss another third by observing that the anthropogenic part represents a gas that is 3% of the atmospheric density of total CO2, which is only 0.04% of the atmosphere. How 3% of such a rare gas could possible affect any kind of warming is the issue. I would conclude, then, that a theory missing 2/3ds of it’s components is indeed crippled.
BS.
That leaves the warming part. As Akasofu pointed out, the IPCC failed to account for warming over the past couple of hundred year due to recovery from the LIA. When the estimated warming is subtracted, what is left could be claimed to be an error. There you have it, a piddly anthropogenic content, no globality, and questionable warming. I’ll have to revise my conjecture: AGW is no longer crippled, it is dead.
The recovery from the LIA is nonsense. What caused the LIA and why are we supposed to be recovering. Until these machanism are is explained this is an empty slogan, not a scientific theory. AGW is a coherent scientific theory accepted by nearly 100% of active climate scientist researchers.
Comment from: Jan Pompe April 11th, 2009 at 10:58 pm
Will
“Jan, you’re a joke. Anytime you are cornered, it’s off to circuits which can’t model the climate.”
I haven’t been cornered by anyone here and you show by this last statement you have been and still are totally clueless about this discussion and have never got beyond the point of sniping with valueless remarks.
The issue has been feedback Eric introduced this equation Eo = AEi/1-AB) that is Eric not me and that equation has been lifted straight out of feedback amplifier theory. I have shown it doesn’t even hold for a simple dissipative electrical system let alone a dissipative climate system. If you have a problem with that equation and the example of what it really represents then I suggest you take it up with Eric.
The equation may look like an electronic feedback amplifier, but it is derived from climate science.
reflecting the dependence of temperature change on change in CO2 concentration and the change in WV concentration, which is itself dependent on Temperature. These are both well understood as a result of the “atmospheric greenhouse effect” and the concentration dependence of water vapor on temperature.
Whatever you have to say about electronics is irrelevant. If they look like something form electronics, so be it. It doesn’t matter to climate science.
Eric
Where on earth do you think they got it from.
So we’ve noticed.
I think Nur Shaviv and friends is doing a pretty job of it and the system he describes is NOT a passive dissipative one like the water vapour case where you are trying to convince that low temperature, low grade, high entropy energy to do a job of work on a warmer surface. The fingerprint of the GCR variations is visible on the climate.
Jan Pompe wrote:
I think Nur Shaviv and friends is doing a pretty job of it and the system he describes is NOT a passive dissipative one like the water vapour case where you are trying to convince that low temperature, low grade, high entropy energy to do a job of work on a warmer surface. The fingerprint of the GCR variations is visible on the climate.
I take it that you are now switching the topic to the cosmic ray theory of cloud formation.
The theory so far has no legs. There is not correlation between cosmic rays and cloud cover.
The cosmic rays are supposed to play the role of catalysts in this theory, but there is no evidence that they are doing anything.
Let us get back to your mischaracterization of the role of entropy in the case of WV.
Your palaver about low grade high entropy energy is nonsense. The earth is not a closed system and the second law of thermodynamics, which you appear to be alluding to in some form does not apply.
Eric
“The equation may look like an electronic feedback amplifier, but it is derived from climate science.”
Where on earth do you think they got it from.
It is simple.
We know at thermal equiliburium the change in temperature due to the greenhouse effect of and increase in CO2 concentration and in increase in WV concentration will be
dT=g*dCO2+h*dWV .
We also know the increase in concentration of WV with temperature will occur.
dWV=j*dWV.
Putting the 2 equations together one gets
dT=g*dCO2+h*j*dT
solving for dT,
dT=g*dCO2/(1-h*j)
provide h*j<1.
No reference to any circuits is needed to do that. It follows from simple models which are based on observations. If the equation looks like a feedback amplifier it is coincidental.
An excellent survey article on forcings and feedbacks has been written by Chris Colose.
http://www.mathaware.org/mam/09/essays/Radiative_balance.pdf
“ACCORDING to the international panel on climate change (IPCC) any direct temperature rise from increasing carbon dioxide levels is greatly amplified by positive feedback from water vapour”
More correctly this is according to climate models, aka our best calculations of physics of the climate. The IPCC report it.
“In this way the roughly half degree direct impact from doubling carbon dioxide is claimed to be amplified to three degrees or more.”
That should be 1C direct impact is amplified to 3C, for the mid climate sensitivity. And IIRC water vapor feedback makes up only about half the 2C warming from feedback, ie about 1C more.
“The amount of positive or amplifying feedback claimed by the IPCC would inflate that about 6 times to more than 90 degrees C, extinguishing all life in Mackay.”
So do the GCMs show 90C temperatures in Mackay? If they don’t (and believe me I am might skeptical that they do…) you don’t really have an argument.
Before trying to come up with a fixed climate model yourself (albeit unquantified, unrun (untested) and rough), you should first at least determine there is a problem to fix.
Folks seem to be having a whole load of trouble with other concepts such as “feedback” and “greenhouse effect” too.
Just saying.
Eric
Don’t go crying “no mechanism” without expecting an answer then complain of a change of topic when someone does. As far as no legs goes the GCR fingerprint can be seen as far back as as the Phanerezoic but for CO2 the only fingerprint is that of temperature on CO2 not vice versa.
An increase of temperature in the atmosphere + an increase in water vapour due to increased transport of heat to the atmosphere due to increased latent heat is to be expected it’s not positive feedback. This should have become very clear in the 1998 El Nino and given that it preceded the 1999 & 2000 MGT crash you are not going to convince anyone except the true believer it’s a positive feedback.
“No reference to any circuits is needed to do that. It follows from simple models which are based on observations. If the equation looks like a feedback amplifier it is coincidental.”
The notion of positive feedback is more general than electrical theory, and it is in fact electrical theory that should look like the general model for positive feedback, not the other way around.
Will
Either way you are not going to get gain in a lossy system without an external or auxiliary source to make up for the losses.
Either way will there is no free lunch to be had.
SJT “The notion of positive feedback is more general than electrical theory, and it is in fact electrical theory that should look like the general model for positive feedback, not the other way around”.
Now you’re talking like a true modeler…all models are right, it’s just a matter of finding out what’s wrong with reality. Jeffrey Glassman revealed one of the top modelers, Schmidt, as not understanding feedback theory, and you’re backing Schmidt. Typical.
Eric Adler “The recovery from the LIA is nonsense. What caused the LIA and why are we supposed to be recovering. Until these machanism are is explained this is an empty slogan, not a scientific theory”.
Oh, I get it. The CO2 density of the pre-Industrial era is pegged at 270 ppmv based on ice core proxies. In the meantime, studies by various early 20th Century scientists, among them a Nobelist, claiming the early 20th century had CO2 densities as high as today are ignored. Yet, there is no proof of the Little Ice Age. Maybe you could explain why the IPCC presented a graph of both the LIA and MWP in a 1990 review., then lost it again when Michael Mann, who had barely graduated with his Ph.D., was given a world stage on which to make a fool of himself and the IPCC.
I’ve put up with you long enough. You’re just a stupid ass.
Jan Pompe “If you have a problem with that equation and the example of what it really represents then I suggest you take it up with Eric”.
Jan…these guys don’t want to know. Positive feedback sounds good to them even if it is impossible without an amplifying medium. If they understood feedback they’d have to give up on the theory, and they’re not man-enough to face that eventuality.
With regard to your resolutions, in Pat Michael’s book from earlier this decade, he reckoned the smallest resolution was about the size of the state of Iowa. I make the area to be equivalent to a latitude/longitude of about 237 miles per side. So, modelers are fitting all their theories into a column 237 miles by 237 miles, with whatever altitude.
The climate where I live changes drastically in 237 miles, from a coastal rainforrest to a desert plateau. There’s sagebrush on the plateau and people go their to film cowboy movies. Not only that, the area is filled with mountains, different kinds of vegetation, valleys, rivers, etc. The weather can change drastically within 100 miles. The temperatures also vary wildly. It can be 20 C on the coast and over 30 C inland.
It’s easy to fool most people with computers because people marvel at them still, being unable to comprehend how they work. Once you’ve taken them apart, studied the software, firmware, memory and controllers, you are no longer impressed with them, unless you’re a shady modeler trying to pull wool over the eyes of the gullible.
Although I can understand certain modelers having integrity, I think those in the forefront of climate modeling are arrogant charlatans.
Hi Gordon I think you’re right and it looks like Eric has gone full circle and I’ve had about enough of it. I wonder what sort of engineer he claims to be. Most I know (apart from software “engineers”) have no difficulty with the notion that water don’t run uphill, ad heat won’t got to hotter.
With grid I knew I was wanting to demonstrate a large figure as I understood the grid cell size to be 5 degrees square ~ 333 KM at the equator so either way they are enormous squares taking in variety of landscapes. All climatologists use models it’s the various different people make of what they doe that makes the difference.
”
Hi Gordon I think you’re right and it looks like Eric has gone full circle and I’ve had about enough of it. I wonder what sort of engineer he claims to be. Most I know (apart from software “engineers”) have no difficulty with the notion that water don’t run uphill, ad heat won’t got to hotter. ”
As I predicted, time to claim victory, despite apparently still being unable to understand the most basic concepts and claims for AGW. No one says heat is going to a hotter body. The net heat flow is hot to cold. A cold body still radiates heat, and it radiates it in all directions, even towards hotter bodies. The net heat flow, though, and thermodynamics, is still intact, the heat flows from hot to cold.
“Now you’re talking like a true modeler…all models are right, it’s just a matter of finding out what’s wrong with reality. Jeffrey Glassman revealed one of the top modelers, Schmidt, as not understanding feedback theory, and you’re backing Schmidt. Typical.”
Everything we write down is a model. It may be a formula on a piece of paper, it’s still a model. Every second topic we see here uses a model of some sort. It’s just that their model disagrees with the models accepted by most scientists. G&T uses models, Miscolczi uses models.
Positive feedback from water vapor is pretty simple.
Warmer temperatures = more water vapor
More water vapor = warmer temperatures
Lets put some numbers behind an example of this.
If for every 1C warming, water vapor increases 1% and each 1% increase in water vapor causes 0.5C warming, then a 1C direct warming from solar output results in:
1C direct increase in temperature causing a 1% increase in water vapor, in turn causing 0.5C additional warming.
That 0.5C additional warming causes a 0.5% increase in water vapor which in turn causes a further additional 0.25C warming.
That additional 0.25C warming causes a 0.25% increase in water vapor which in turn causes a further additional 0.125C warming.
You can see this goes on and on and on, but the additional warming from each step halves each time. Lets add it all up so far. We have 1C direct warming, 0.5C from the first round of feedback, 0.25C from the second and 0.125C from the third. In total that’s 1.875C of warming.
In fact if you continue the steps to infinity the total warmign is 2C (and no more)
To sum up this example – the positive feedback in this case is 100% amplification of the initial warming. Ie for every 1C driven warming, the water vapor feedback causes an additional 1C warming.
This doesn’t result in runaway because f<1 (in this case f=0.5), the series converges to 2C
Will you really don’t get it do you?
That is precisely what you are doing if you claim there is positive feedback resulting from increased optical depth in the atmosphere.
“An increase of temperature in the atmosphere + an increase in water vapour due to increased transport of heat to the atmosphere due to increased latent heat is to be expected it’s not positive feedback. This should have become very clear in the 1998 El Nino and given that it preceded the 1999 & 2000 MGT crash you are not going to convince anyone except the true believer it’s a positive feedback”
Positive feedback doesn’t mean temperature cannot fall again. Positive feedback simply amplifies the input. If the input drops then so does the amplified output. In fact with positive feedback the output drops faster.
Positive feedback works both ways – it both amplifies temperature rises and amplifies temperature drops.
Take a situation without feedback where temperature rises 1C and then later falls 1C. If you instead have positive feedback with f=0.5, then temperature will rise 2C and later fall 2C.
Positive feedback basically increases the variation, negative feedback reduces it (ie a rise of 0.5C later followed by a fall of 0.5C)
Fred
I realise that Fred with 30 years of feedback and control behind me. I think you miss the point and you don’t quite have this right
Even .5 (or 50%) positive feedback will drive the system to the rails (a climatic equivalent of Schmitt trigger) and we haven’t this in earth’s climate since the Ordivician.
The problem is getting feedback in the first place where the potential parameter temperature, water or simply height in a gravitational system is higher at the input than the output. Imagine a dam with the generator at the end of a pipe at the bottom of a hill do you really think you can goose up the output of the generator by running a pipe from the outflow of the the turbine back up the hill to the top just below the inlet of the pipe? All that you will do is waste the water flow by sending it down past the generator’s turbine.
Consider what happened at the 98 El Nino there was a temperature spike, vapour spike, and a CO2 increment spike none of that was feedback it all had a common cause and that was the up welling of warm water in the east pacific ocean.
“Even .5 (or 50%) positive feedback will drive the system to the rails (a climatic equivalent of Schmitt trigger) and we haven’t this in earth’s climate since the Ordivician.”
A 50% positive feedback would mean a climate sensitivity of 0.5C/wm-2. That wouldn’t drive climate to the rails. In fact that would imply the forcing out of the last glacial period must have been a whopping 10wm-2.
“The problem is getting feedback in the first place ”
This isn’t a problem at all. Which one of these don’t you accept:
1) Warming causes rise in water vapor in the atmosphere
2) Rise in water vapor causes warming
Given both of these are true the result is positive feedback.
“Consider what happened at the 98 El Nino there was a temperature spike, vapour spike, and a CO2 increment spike none of that was feedback it all had a common cause and that was the up welling of warm water in the east pacific ocean.”
Can you prove that the water vapor increase from that event didn’t cause any warming itself? That would seem to defy point #2 above. If water vapor increase did cause warming, that’s a positive feedback as the water vapor increase itself was caused by the temperature increase.
Fred
Those of us who use it that is anyone of us who use positive feedback will tell you that to get a decent hysteresis we use about .1% positive feedback and it snaps back and forth quit nicely. Have you ever used positive feedback devices?
I really have no idea what you are on about here but I can assure there is no evidence of positive feedback the past million years at the very least.
You are wandering in the long tall grass more water vapour rising transports more heat to the atmosphere were it is radiated out it causes cooling of the surface. AS for point 1 it depends on what has done the warming if you put more heat into the surface from SW you get more water vapour AND higher temperatures you can also get this from heat stored in the ocean when it wells up. In both cases it’s not feedback. Now if you don’t have either of those events and you increase the optical depth and you don’t have more incoming flux or from up welling warm water the the heat in the atmosphere came from the surface it cannot come back to the surface to lift more water out because at 2260 Joules/gram to vaporise water it will cool the atmosphere again and fast. (2260 joules will warm ~1kg of water 1 C and about 2kg of air 1C).
You simply cannot use the heat from the surface that has warmed the atmosphere again at the surface to cause more evaporation that is what the second law is all about. These processes are not reversible.
It’s simple. Without any feedbacks climate sensitivity is about 0.25C/wm-2. With positive feedbacks it’s greater and with negative feedbacks it’s less.
You are basically arguing that any climate sensitivity higher than 0.25C/wm-2 would destablize the climate. That is incorrect.
“AS for point 1 it depends on what has done the warming if you put more heat into the surface from SW you get more water vapour AND higher temperatures you can also get this from heat stored in the ocean when it wells up. In both cases it’s not feedback.”
No the positive feedback is due to the fact that the higher temperatures will cause water vapor levels to increase, which in turn causes even higher temperatures and more water vapor level increase. This is what the “feedback” part means.
In short, more incoming solar energy would warm the surface and atmosphere. That warming will cause water vapor level to rise in the atmosphere, which enhances the greenhouse effect and itself causes additional warming. Ie the total warming from an increase in solar output is greater than the direct solar warming alone. It’s amplified by the increase of water vapor caused by the rise in temperature. That’s the feedback, it’s not difficult to grasp.
“That’s the feedback, it’s not difficult to grasp.”
It is if the only models you can understand are electrical ones, and you can’t think of the components needed to simulate the climate.
No Fred I’m not
I am saying positive feedback if it existed in the climate system would destabilise it that is what positive feedback does it is well understood by Electronic Engineers, Control Engineers and Rocket Engineers but not generally by physicists or climatologists. It’s a matter of training an experience.
There are however exceptions for example Garth Paltridge et al from the abstract of his latest
[emphasis mine]
This has in fact been verified by Ferenc Miskolczi by doing a LBL analysis of the varying optical depth of the atmosphere due to CO2 + H2O changes up to 300 mbar level but has not be published yet. His results were posted up by Ken Gregory on CA forum and they show no trend for optical depth the past 60 years (I have the results for 2008 and it hasn’t changed).
SJT
Still just sniping and nothing substantive.
“I am saying positive feedback if it existed in the climate system would destabilise it”
Sounds like a purely an argument over definitions then.
To me there is a positive feedback here:
Temp = SolarOutput + WaterVapor
WaterVapor = Temp * 0.5
The water vapor introduces a positive feedback as far as temperature goes, because any increase in temperature feeds back into itself due to the increase in water vapor.
The equations above boil down to:
Temp = SolarOutput + Temp * 0.5
Which means:
Temp = 2*SolarOutput
Whether or not you choose to call this positive feedback, and personally I will continue to describe it as such, this represents an amplification of the direct warming from the forcing agent (in this case solar).
In fact I don’t know how this cannot be called a feedback. You have temperature increase causing water vapor increase which in turn causes more temperature increase. Under what definition is that not a feedback? It “feeds” “back” into itself.
Fred
A bit of water vapour halves the temperature? I think you exaggerate, getting closer to the sun is not going to do that.
Try not to make up your own definitions it tends to be confusing. Feedback is where a bit of the output (or result) is sampled an sent back to either enhance or correct the input. What you are showing is an adaptive parameter change which can be either feed forward or feedback but you have to do the energy budget and take into account directions of flow and which is cause and which is effect to come up with a coherent theory. If the supposed source of the heat that is going to cause more vapour to be produced is cooler than the surface water that it’s supposed to evaporate then it isn’t going to happen.
“Still just sniping and nothing substantive.”
I am describing what you are doing. An argument from ignorance.
Will <blockquote.An argument from ignorance.
I would be surprised if you even knew what that meant.
“I would be surprised if you even knew what that meant.”
What was that about pointless sniping?
Just pointing out what you were doing AND that in your sniping you are using terms that you don’t understand.
Jan Pompe says:
The definition of “feedback” used in climate science is not the same as that used in other sciences, especially electrical circuits. In this blog we are discussing climate science, so we need to use the climate science definition.
In electrical circuits or control systems, a signal from the output added to the input for a circuit would be a positive feedback, and would cause the output to increase without bound. Any positive feedback would be unstable. No feedback means the output does not affect the input.
In climate science, the point of zero feedback has been redefined to be the temperature response to a forcing when allowing the outgoing longwave radiation (OLR) from the top of the atmosphere (TOA) to increase. If the surface temperature is increased by 1 C, and water vapour and clouds are held constant, the black body emissions of OLR from TOA would increase by 3.3 W/m2.
This extra OLR cools the planet in response to a forcing. This would be called a negative feedback using the control systems definition, but is called zero feedback in climate science.
So a positive feedback can be a stable in climate science, while a positive feedback in control systems is unstable.
Roy Spencer has a post of this subject
http://www.drroyspencer.com/2009/04/when-is-positive-feedback-really-negative-feedback/
Jan Pompe says:
In climate science, the zero feedback case by definition is the effect of the up-welling of warm water where you assume the water vapour and CO2 remain constant. The up-welling of warm water would cause some near surface air temperature change, which is the no-feedback case. This temperature change also caused an increase in water vapour and CO2, which would cause a further temperature change. This is the with-feedback case. So while Jan correctly states that the temperature spike and the water vapour spike had a common cause, by definition, the portion of the temperature spike caused by the water vapour spike is a feedback.
“The definition of “feedback” used in climate science is not the same as that used in other sciences, especially electrical circuits. In this blog we are discussing climate science, so we need to use the climate science definition.
In electrical circuits or control systems, a signal from the output added to the input for a circuit would be a positive feedback, and would cause the output to increase without bound. Any positive feedback would be unstable. No feedback means the output does not affect the input. ”
The “feedback” is “feedback”. If you look at the climate on geological time scales, it does indeed swing to extremes.
Ken this almost does me
The sort of thing you and Roy are talking about is already covered in feedback and control engineering is adaptive (parameter) control but it sounds like they have gone out of their way to confuse themselves along with everyone else.
I guess it boils down to whether we consider this equation describes a system with positive feedback:
A(t+1) = N + A(t) * f
Obviously it converges as long as that f term is less than 1. Certainly the output is fed back into the input. I would describe f>0 as positive feedback and f<0 as negative feedback, simply because f=0 is no feedback at all.
Fred if the potential of the output is less than the input’s there is no feedback only forward feed.
Earth emits thermal energy in the form of oxygen 300ton / d as well as hydrogen and helium.
Furthermore, the “cold” matter into the atmosphere.
The atmosphere will never end and enclosed by the sun’s atmosphere.
Molecules far can deliver its thermal energy to the particles just passing.
For those who believe that the Earth emits all its terimska energy in the form of radiation.
Or am I wrong?