GLOBAL warming theory is not that complicated. According to Michael Hammer it can be incorporated into a simple model which readers can build themselves on an excel spread sheet.
Mr Hammer gives detailed instructions and formulae to enter for his DIY climate change model. The model then calculates the temperature rise from carbon dioxide plus water vapour forcing and allows for the time constant in the system.
A temperature rise by 2070 of 3C for a business as usual scenario, however, gives model output that is not compatible with what we know of past climates. So, what is wrong with Mr Hammer’s model?
A SIMPLE MODEL OF THE IMPACT OF CARBON DIOXIDE ON GLOBAL TEMPERATURE
By Michael Hammer
The basic claim of the anthropogenic global warming theory is that rising carbon dioxide levels increase the retained energy and thus causes the surface of the Earth to warm. A further claim is that this warming in turn causes water vapour concentrations in the atmosphere to rise causing even more energy retention in a positive feedback loop.
The relationship between concentration and energy retention is very widely accepted to be logarithmic in nature. Thus the additional forcing from carbon dioxide is proportional to the logarithm of the concentration change. In the case of water vapour the relationship is also logarithmic but the relationship between temperature and concentration is exponential. Thus the relationship between temperature and additional water vapour forcing is the logarithm of an exponential which is linear.
A third point of significance is the claim that the ocean has enormous thermal mass and that this imposes a long time constant on temperature changes. Since the water vapour level depends on current temperature this time constant also affects the water vapour feedback.
It is easy to incorporate these claims into a simple model as shown here, click on the image for a better/clearer and larger view.
IPCC in their 4th assessment report claimed that the increase from 280 to 390 ppm had increased direct forcing by 1.77 watts /m2. This translates to 3.7 watts /m2 per doubling. Thus the forcing from carbon dioxide becomes;
Forcing = 3.7 * log (current CO2 level/280)/log(2) which simplifies to
Forcing = 12.3 * log (current CO2 level/280)
This is the equation defining the first box.
IPCC also claim the direct effect of doubling CO2 is a 1 degree increase in temperature hence the climate sensitivity is 1/3.7 C per watt or 0.27 C per watt.
This is the climate sensitivity term.
Dressler has recently claimed the water vapour forcing is 2 watts /m2 / C however this does not include cloud feedback. To include that we will have to make some estimate of this value so this becomes a parameter we adjust in our model.
The general form of the equation for a simple time constant is
New output = K* new input + (1-K)* old output where K = 1/time constant.
Technically this is known as an infinite impulse response digital filter. It is probably not obvious why this should give a time constant but rather than explain filter theory here, those interested are urged to try the equation for themselves and confirm that it does indeed give a response of the form (1- e-time/time constant).
The time constant is also not known with any precision so again we will have to make some estimate. A second adjustable parameter in our model.
Mauna Loa data gives the carbon dioxide levels for the period from 1959 to 2008 and this conforms extremely well to the equation
CO2 concentration for year X = 0.012029X 2 – 46.287X + 44828
Where X is the year starting at 1959
Because X is very large the equation is very sensitive and does require the number of decimal places given for coefficients to give the correct answer. A less sensitive equation giving the same answer is
CO2 concentration = 0.012 * X2 + 0.843 * X + 315.2
Where X = (year – 1959)
These equations predict that carbon dioxide will reach 560 ppm in 2071 which is exactly in line with IPCC claims.
The model can be created and run on an Excell spreadsheet. Each column gives a different parameter as outlined below. Successive rows gives results for successive years and we will use 111 rows to cover the years 1959 to 2070. Since we have two parameters we can adjust we will enter these parameters in cells A1 and A2 as outlined below
Set A1 to the estimate of water vapour feedback coefficient (value entered by modeller)
Set A2 to the estimated time constant (value entered by modeller)
Set B2 = 1/A2 giving the value K from above
Then starting in row 4
A4 = 1959 (the year) incrementing by 1 for each row downwards ie: set
A5 = A4 +1
B4 = 0.012 * (A4-1959)^2 + 0.843 * (A4-1959) + 315.2 the carbon dioxide level for that year using the above (less sensitive) formula
C4= 12.3 * log ( B4/280) the CO2 forcing function for that year
D4 = C4 + $A$1 * F3 the total forcing function including water. Column F is the estimate of temperature rise for that year
E4 = 0.27 * D4 the total forcing divided by the climate sensitivity
F4 = $B$2*E4 + (1-$B$2)*F3 our time constant. Each value in column F gives the predicted temperature (above baseline) for the year as specified by the column A value for the same row.
Set F3 = 0 as an initial condition. This is only to ensure a starting point for the time constant filter.
Now fill down columns B to F from row 4 . Fill down column A from row 5 (we set A5=A4+1). Do this for total of 111 rows so that A115 = 2070.
This is our model. It embodies the IPCC data and should account for both the direct forcing from CO2 and the water vapour feedback effect claimed by IPCC.
IPCC claim 0.5 C of warming up to 2008 and a further 3C of warming by 2070 for a total of 3.5C above 1900 temperatures.
Each change to A1 or A2 will automatically run the model giving the new temperature predictions. Try first a water vapour feedback value of 2 watts/m2 / C as claimed by Dressler (A1=2). Adjust A2 to match the 0.5C rise in 2008 (I found a time constant of around 20 years ie: A2=20). Note the total rise in 2070 – about 1.42C or 0.92C above today’s temperatures. I could not find any choice of time constant which gave 0.5C in 2008 and 3.5C in 2070 (3C rise above 2008 value).
In order to fit both the 2008 claim and 2070 prediction it is necessary to increase the water vapour positive feedback coefficient to around 7 watts/m2 / C with a time constant of around 45 years. However, there is a problem with such a scenario. It means a 1C rise in temperature causes water vapour feedback to increase retained heat by 7 watts/m2. For a temperature sensitivity of 3.7 watts/m2 / C that implies a further rise of 1.9C. This is almost double the positive feedback needed for thermal runaway even without any external forcing at all. Clearly, if that were the case, the climate we have had over the last several million years would have been impossible. It would have boiled the oceans billions of years ago, irrespective of carbon dioxide levels.
If as many predict, cloud feedback is negative and possibly strongly negative, say -2 watts/m2 /C or more, then a1 = 0 or negative. Even with a very short time constant a value of A1 = 0 gives a maximum temperature rise by 2008 of 0.45C and by 2070 a further 0.53C. Still stronger cloud feedback reduces these numbers even further. Programming this model only takes a few minutes, I urge people to do that and explore the range of outputs.
The model suggests that a temperature rise by 2070 of 3C for a business as usual scenario is not compatible with a past climate that has been stable enough for life to have continued to flourish. Question, where is the error in this model?
For those tempted to dismiss this on the basis that the model is too simple, consider first what such a statement implies. It suggests that the other factors not considered above in fact account for most of the predicted temperature rise. If so then the factors that are considered above are minor players.
Michael Hammer
Melbourne, Australia
More posts by Michael Hammer here: http://jennifermarohasy.com/blog/author/michael-hammer/
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Way too simple. Too easily understood. Can’t be right!!!
if my simple model is wrong, a more complex one can NOT be right.
you don t belief in logic, do you?
The main problem I see is that climate sensitivity should be an output not an input.
Climate sensitivity is the total temperature rise from a 1wm-2 increase in forcing, including any warming from feedbacks that occur. So it isn’t something you can decide ahead of time and only later add feedbacks in. The climate sensitivity will already contain the water vapor feedback.
Try a climate sensitivity of about 0.75wm-2 and set A1 to zero
0.27C/wm-2 would be better expressed as the amount of warming per 1wm-2 forcing without feedbacks.
If climate sensitivity was 0.27C/wm-2 then doubling co2 would lead to about 1C warming (0.27 * 3.7 = 1). However the 0.27C/wm-2 value for climate sensitivity is based on no feedbacks.
So lets go with Dessler’s 2 wm-2/C for water vapor feedback. That is any 1C increase in temperature will cause a 2wm-2 forcing.
So first we double co2. That leads to a 3.7wm-2 forcing and without feedbacks is enough to push temperature up 1C. That 1C temperature rise will in turn be amplified by the 2wm-2/C water vapor feedback.
This is an iterative process:
Step 1)
3.7wm-2 forcing from co2 causes 1C temperature rise
The 1C increase in temperature causes a 2wm-2 forcing due to water vapor feedback
Step 2)
2wm-2 forcing causes a 0.54C increase in temperature (2 * 0.27)
The 0.54C increase in temperature from water vapor feedback causes a 1.08wm-2 forcing
Step 3)
1.08wm forcing causes a 0.29C increase in temperature (1.08 * 0.27)
The 0.29C increase in temperature from water vapor feedback causes a 0.58wm-2 forcing
In the first three steps we have a temperature rise of 1C + 0.54C + 0.29C + …
We can continue thought hundreds of steps, you can see that the numbers are getting smaller, ie this sequence converges. This sequence actually converges on 2.17C total warming. So a 3.7wm-2 initial forcing has led to 2.17C warming. That makes climate sensitivity 2.17 / 3.7 = 0.58C/wm-2
Why is 2.17C per doubling of co2 less than the 3C in the IPCC reports? Because we’ve only considered water vapor feedback and left out ice albedo feedback.
Doesn’t have:
Clouds
Aerosols
Internal variability
Atmospheric circulation
Variable solar input
and
GCMs don’t have a parameter called “climate sensitivity”
Lol, time to put up the feet, pour a nice malt and enjoy the show.
Good morning sod. You are significanrtly misquoting me. I have not said that if a simple model is wrong a complex one cannot be right. What I have said is that here is a simple model whcih covers the claims of the AGW advocates yet is shows that the projeted temeprature rises are not possible. Please show where this simple model is in error. I reject any implication that it must be wrong just because it is simple.
Bob; with regard to youir first post, I disagree that climate sensitivity is an output or for that matter an input either. Climate sensitivity is an inherent attribute of the system. The temperature changes not as a result of changes to climate sensitivity but rather due to changes in energy input including feedbacks. Since the mass of the oceans, land distribution, etc are all not changing there is no reason to assume climate sensitivity would change. Also please note, the value I used is the value claimed by the AGW advocates.
With regard to your second post. I have no argument at all with your mathematics. In fact, you don’t need to use an iterative solution. Consider if CO2 forcing is 3.7 watts/doubling, water vapour feedback is 2 watts/degree C and climate sensitivity is 3.7 watts/C then let the temeprature rise = T it follows that
3.7 + 2*T = 3.7 * T hence 3.7 = 1.7 * T
hence T = 3.7/1.7 = 2.18 C
This all follows from the initial values you used (and yes they are the same values I used because they are the values claimed by the AGW advocates). However what you have calculated is the equilibrium value. What I am trying to show is that dynamically if the rise is 0.5C by 2008 then the equilibrium value cannot be reached by 2070 and if the equilibrium value is reached by 2070 then the rise by 2008 would have to be much higher.
Why is this important? Because it suggests that the projected values are not internally consistent and that something is wrong. Either the time constant is long in which case the rise by 2070 is much lower or the time constant is short and the rise by 2008 should have been much higher. In the latter case it implies the input data is seriously in error or there are other factors whuich have not been considered.
Just a brief note here, but it doesn’t seem like the water vapor forcing can possibly be as high as 2w/m2 with the commonly held total forcing for WV being somewhere around 75W/m2 total and 32W/m2 for CO2.
If each 1C causes a 2W/m2 ‘forcing’ in WV, then following from the Clausius-Clapeyron relationship we are saying that a 7-8% increase in WV causes a 2W/m2 forcing.(C-C determines the equilibrium balance btw the liquid and gas states of water).
http://en.wikipedia.org/wiki/Clausius-Clapeyron_relation
However, a if 7% increase in concentration gives a 2W/m2 forcing, then a doubling of WV would give approx 20W/m2 — 2W/m2 divided by[ln(1.07)/ln(2)].
Even if we assume that there is only 4 times as much WV in the atmosphere as CO2 we still can’t make the totals make sense.
If CO2 has undergone X doublings to reach 390ppm, and WV has undergone X+2 doublings, and we know that each doubling of WV gives 20W/m2 and each doubling of CO2 gives 3.7W/m2
Total forcing for WV=75W/m2=20*(X+2)
Total forcing for CO2=32W/m2=3.7*X
You get two different answers for X(the number of doublings required to reach 390ppm) which makes no sense.
Cheers, 🙂
You need to read this.
http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/
Your CO2 forcing will be too low without taking it into consideration.
Climate Models can be used to get an estimate of climate sensitivity, they don’t assume we already know it.
I agree with Mike that climate sensitivity is neither an output or imput; in fact it is an intensive property of the climate system. If we accept Miskolczi then CS is equal to the greenhouse effect or Tau; if we accept Steve Short’s revison of Miskolczi then CS /= Tau but is, like M theory, fixed to an equilibrium climate. OTOH AGW defines CS in terms of varying equilibriums which in turn are defined by temperature. For instance, a doubling of CO2 will set a new equilibruim of ~ 3C increase in GMST.
So, for AGW CS is not an intensive property but an extensive property which can be defined/measured/predicted depending on the amount of relevant forcing elements in the system. This is fundamentally different from the Miskolczi and Short concepts in which prediction is irrelevant because of the reversionary or constrained nature of the climate system; so for M and S CS is effectively zero.
The difficulty for AGW CS is the difference between the transient climate response [TCS] and the equilibrium climate sensitivity [ECS]. The difference between these 2 is referred to in Mike’s model by the time constant. Simplfying Mike’s formula we can say if a doubling of CO2 [with AGW assumed WV feedbacks] causes temp increase of ~3C then at any one time before that doubling the temp response to whatever CO2 increase will only be the TCS with the ECS delayed depending on system lags. So. if we say CO2 went up ~ 30% from 1900 – 2000 then the temperature increase between 1900 – 2000 will only be the TCS; here is what temps did;
http://tamino.files.wordpress.com/2008/01/smooth.jpg
Temps increased 0.4C; a 30% increase in CO2 should have produced an increase of ~ 0.9C. Superficially, therefore the lag component is 0.5C. But this needs to be varied because the 0.4C temp increase is not without ‘natural’ forcings. Increase in insolation contributed ~0.16C, while PDO contributions are at least 0.3C. The natural forcings therefore exceed the total temp increase! Since the temp increase from the natural forcings are capable of being accurately measured we cannot say that the CO2 + WV forcing has been masked by contrary natural forcings because to mask the CO2 effect the natural forcings would have had to be larger and consistently opposite to CO2 forcing; during the 20thC there was only one -ve PDO and insolation was increasing until near the end of the 20thC. A natural forcing increasing temp should have boosted the temp increase from CO2 but we see no evidence of this.
The only alternative to explain why the CO2 effect has not been manifest is to invoke the lag. But if no CO2 effect has been manifest and with CO2 still increasing the prediction of an increase of 3C for 2XCO2 becomes problematic. With ~ 30% of the 2XCO2 already happened with no apparent TCR, that is manifest temp response to the movement in CO2, how can there be later an ECS response to 2XCO2? To achieve the ~3C increase to 2XCO2, with already a ~30% increase of CO2 by 2000 with no temp CO2 response, the remaining 70% increase in CO2 would have to produce the equivalent of a 4.3C increase for 2XCO2. 4.3% is within the IPCC range of equilibrium CS, so the issue is the lag; when does the CO2 effect kick in?
Ocean heat content is falling; the recent Levitus paper finding an increase in OHC is contradicted by Willis et al, Doiminques et al and Loehle. With OHC declining the pipeline effect to provide the lagged response to 2XCO2 is problematic especially since various papers by Trenberth, Tsonis and Schwartz find lags between a few months to 5-8 years. In otherwords the CO2 effect should have been occuring already as defined ECS points during the 20thC.
So, with no apparent TCR by temp to CO2 and no definable ECS peaks reached during the 20thC, and with no satisfactory lags to explain a delayed temp response one can only conclude that CO2 has no measurable effect on CS.
Hello, I’m about to commit two mortal sins in a single comment. Please forgive or ignore me, whichever is more convenient, but understand that you will only force me to go bug someone else ; )
First, I’m going to admit that I’m way too stupid (or lazy) to understand this post. Second, I’m going to ask a climate question that is somewhat off-topic, but which I have been unable to get a sufficient answer to elsewhere. (see, if they had just answered me at other places you wouldn’t have to ignore me here)
Regarding MSU data, all the charts I see register figures from -70 degrees to somewhere around 85 degrees latitude. The most popular reason I’ve seen given for stopping at -70 degrees is that Antarctica rests at an elevation that extends into the lower troposphere. I’m good with it (what other choice do I have?). But here’s my question; people are using combined readings from the MSU data, so far as I can tell, to create mean global temperatures, or MSU equivalents, by year. This is then used to demonstrate whatever they are wanting to demonstrate, generally anthropogenic global warming. Yet that absent 20 degrees at the southernmost portion of the globe doesn’t seem to be negligible. Recent analysis, despite reports of Antarctica warming, show that there is more ice in Antarctica now than in 2001, indicating that this area has been cooling.
So are these studies simply ignoring those 20 degrees, a significant portion of the planet, or are they using some sort of modeling to include them in the figures? And, in any event, doesn’t it seem that there would be a movement, likely downward, of the temperature trend if this area could be measured by MSU readings and temperatures there are, in fact, dropping?
I ask this because I ran some MSU figures and used regression analysis to look for trends, and even without the Antarctica figures, my trend line was downward (just for the limited time period I chose). Assuming that I got my math right and that my presumptions regarding Antarctica are correct, I would expect my slightly downward trend to get significantly steeper, even accounting for being able to go back and insert data for Antarctica (which I obviously can’t do since it doesn’t exist) back to my starting year. I also acknowledge that had I gone back to 1979 that my trend line would have been entirely different and upward, but that wasn’t the timeframe I was interested in.
Essentially, isn’t excluding Antarctica in these readings producing useless results? Taken to ridiculous extremes to prove the point, you couldn’t take readings from 20 to 40 degrees latitude and declare the planet was warming and that Australia was going to be covered by the ocean due to melting ice. Do they just assume that -70 to 85 is enough to get a general, supposedly definitive, picture of climate change?
Thanks. I’m sure that comment was laden with naive ignorance, as I only started my quest for climate knowledge on Monday of this week, but a response would be truly appreciated.
Michael Hammer beat me to it in simplifying Bob’s iteration, but here was my take.
CO2 doubling originally results in a 3.7 Watt increase. This in turn leads to a 2 watt increase in water vapor. This should result in a total water vapor feedback of
3.7 ( 1 + 2/3.7 +( 2 /3.7)^2 +……… (2/3.7)^n+…. and this series converges to
1/{1-(2/3.7)} = 2.176… the same figure as bob’s and Michael Hammer’s.
Incidentally, Trenbeth gives nearly 100 watts eaten up in conduction and convection, close to 20% of the total. At a temperature just above freezing, there would be a lot less water vapor in the air, and the percentage of heat eaten up by convection should be a heck of a lot less. I suspect the percentage of any increase in wattage eaten up by convection should increase with increasing temperatures. Assuming conservatively that only 20% of that additional wattage increase was eaten up by convection, rather than a 2.176 watt increase for a doubling of CO2 and water vapor feedback, we’d get
0.8 times that series, or 1.74. If, as is more likely, the water vapor feedback is 0 or negative,
the increase in temperature from a doubling of CO2 would be less than 1C.
A few replies. Luke; I think you are missing the point. IPCC claim that the direct effect of CO2 doubling is about 1C with positive feedback amplifying this to about 3C. That positive feedback must be due to the intial temperature rise from the CO2. It really makes no difference what the postive feedback mechanism is, whether water vapour directly or water vapour via clouds or anything else. Its still positive feedback generated by the intial rise in temperature. Thats what I am modelling and the model shows the 0.5C in 2008 and a further 3C by 2070 are not compatible with a climate system what has allowed life to develop and flourish (ie: positive feedback less than 1)
Shawn H; I tend to agree with you. I don’t agree with the IPCC numbers at all but I was accepting them for the purposes of this analysis to show that even if one does accept them there are still inconsistencies in the conclusions that need some explanation.
SJT; I read the link you provided. If you look at my very first posting on Jennifers site you will see that I consider his exact point not qualitiatively as Gavibn did but quantitatively. The analysis is there if you want to look at it. However, I do not see that it has any particular relevance to this posting.
SJT; re your second posting, climate sensitivity is an attribute of the system and therefore pretty well constant. I can readily accept that we don’t know it and indeed maybe the IPCC number comes from climate models. I have no problem with that scenario however I am using the IPCC estimate and the simple model shows an inconsistency. If you think the value is wrong, make it an adjustable parameter in the model and see what happens as you adjust it. Can you get a result whcih shows 0.5C in 2008, a further 3C by 2070 and a positive feedback coefficient working out to less than 1. I don’t think there is such a solution but I am very willing to be proven wrong.
well, I must admit he’s fairly close to outcome C – unfortunately outcome C is his projection if we stop emitting CO2 – which we haven’t – outcome A is what we are supposed to be following as it’s based on us continuing as normal with no reductions, like we have.
< sorry – wrong forum
now back to deltoid where Tim thought Hansen’s projections were accurate .
You’re spreading yourself too thin janama; I saw you over at Lucia’s on this Monckton [I presume] topic; anyway, say hi to Timmah for me will you.
“SJT; re your second posting, climate sensitivity is an attribute of the system and therefore pretty well constant. I can readily accept that we don’t know it and indeed maybe the IPCC number comes from climate models. I have no problem with that scenario however I am using the IPCC estimate and the simple model shows an inconsistency.”
Perhaps the discrepancy is with your simple model. The link I gave you indicates why the CO2 response is not purely logarithmic, for example. You have identified that they consider more factors in climate sensitivity than you are.
sjt,
Just as he warned in the last paragraph of his post.
“For those tempted to dismiss this on the basis that the model is too simple, consider first what such a statement implies. It suggests that the other factors not considered above in fact account for most of the predicted temperature rise. If so then the factors that are considered above are minor players.”
““For those tempted to dismiss this on the basis that the model is too simple, consider first what such a statement implies. It suggests that the other factors not considered above in fact account for most of the predicted temperature rise. If so then the factors that are considered above are minor players.””
And as I pointed out, the CO2 response will not be a simple logarithmic one. The simple response is, and this was understood long ago. It is the non logarithmic response that is one of his missing factors, and it is one that is directly related to the CO2 content of the atmosphere.
Michael Hammer “It really makes no difference what the postive feedback mechanism is, whether water vapour directly or water vapour via clouds or anything else. Its still positive feedback generated by the intial rise in temperature”.
Michael…what in the heck are you talking about? You’re an engineer, where’s the amplification coming from for your positive feedback? The AGW theory claims a mysterious amplification factor but don’t elaborate, to my knowledge. Roy Spencer has acknowledged that climate science redefined positive feedback in a manner that reflects negative feedback in engineering.
If the heat that warms the GHG’s comes from the surface IR, that is a ‘LOSS’ at the surface. that heat has to be made up before you start talking about amplification. Along the way, you kmight try addressing the 2nd Law.
Could you please put away the math for a moment and explain where the heat comes from to create the positive feedback. Plaease don’t claim it comes from the Sun, since solar energy heated the surface in the first place…which heated the atmosphere, at a loss.
Gordon,
Excellent point – how about describing the Sun-Earth system electrically, with the heat radiated from both the Sun and Earth included?
Both of you are engineers, so between the two of you, the model could be expressed in more detail that at present.
I am only a mere geologist limited to throwing rocks at idiots.
Improve your aim Louis!
They are sprouting like mushrooms!
pz; the problems with temperature data from the Antarctica are well covered in the treatment given to the recent Steig paper at WUWT, CA, Jeff Id’s blog and here at Jennifer’s; just do a search for stinker, er, sorry, Steig.
Well said PZ.
Michael my problem is that climate sensitivity is an emergent property of the climate simulation. There is no switch marked climate sensitivity. And there a range of counterintuitive secondary feedbacks.
Also and unlike PZ not knowing what I don’t know which is a lot here – the fact the GCMs produce circulation patterns and redistribute heat globally makes your simplification problematic. (IMO)
As for “a climate system what has allowed life to develop and flourish ” – well perhaps but many many species didn’t make it through climate transitions. Indeed genetic analysis and paleoclimatic data indicate humanity itself may have had an early brush with extinction.
Louis – “I am only a mere geologist limited to throwing rocks at idiots.”
You mean “I am only a mere geologist limited to throwing rocks”
Luke,
No, you have it quite wrong – I do mean throwing rocks at idiots. You just verified it.
And in a technical sense, climate cannot be modelled as it is a human valuation of the physical state of a part of the earth’s surface. We have desert climates, tropical climates, and so on.
These physical states cannot be easily incorporated into a single one that could be described by a computer model, for it requires incorporating desert, temperate and tropical climates, as well as polar ones.
So do so would be to admit to scientific incompetence, though that is par for the course in climate studies.
SJT: sorry but again i have to disagree with you. Line absorption profiles follow a Voigt profile. I have integrated the area under this profile at various concentrations. When i also included the effect of the analysis described in my first post on Jennifer’s site I then got an almost perfect agreement to a logarithmic response. Hence the analysis I did (which converts the loss from 10^-N to 1/N) needs to be incuded to get the logarithmic response.
Gordon; you express surprise at my posting and claim there is no mechanism for positive feedback. I thought I had made it very clear that i do not agree with the IPCC data. HOWEVER, for the sake of this post I indicated I am using their data. Why? because if I used data I think is closer to the truth that would be used as the excuse why I get a different outcome. By using their data I overcome that issue and my point here is to show that even using their data an 0.5C rise by 2008 does not fit with a further 3C rise by 2070. The 0.5C by 2008 is experimental (although not all is necessarily due to CO2) which sort of leaves 3C by 2070 out in the cold.
Louis; of course the model can be expressed in a more detail, I am trying to make it as simple as possible to show the essence of the conflict in the IPCC claims.
Luke; as to your reponse to my comment about climate being stable enough to allow life to continue to flourish, you misunderstand what I meant. If the positive feedback goes above 1 the system runs away even without any forcing. In this case, what that means is the temperature increases until all the oceans boil away completely. There would be no liquid water on the planet. Further and more significantly, before life started on earth the current oxygen would have been carbon dioxide because oxygen is very reactive and would have long reacted with the free carbon. It is photosynthetic life that reduced the carbon dioxide to free oxygen and carbohydrates, cellulose and the like. Thus before life formed, the CO2 level would not have been 280ppm or 380 ppm but more like 200,000 ppm. If the feedback could go above 1 the earth’s surface would never have cooled enough for life to start in the first place.
With regard to your comment about counter intuitive secondary feedbacks. Could you give some examples specifically showing how these are topologically different from a feedback derived from the rise in temperature. If they are not topologically different from the temperature induced feedback I show, then the model I give is still appropriate. Just change the definition of my temperature feedback to be water plus cloud plus X plus Y plus Z feedbacks. They will just all add to form one composite feedback term. If the mechanisms you are thinking of are topologically different, explain how and I will try expanding the model to incude them. We can then look at the output again.
PZ; you make some interesting points, I have to apologise, I don’t know the answer to your query. Maybe someone else commenting here can help.
So luke, CS is an emergent property? I’d have thought that AGW theory regards CS as an epiphenomena; CO2, of course, is the epiphenomenon.
Perhaps this has been covered, and I missed it, but:
Increased humidity and temperature lead to an increase in convection.
Convection takes warm air and shoves it skyward, sometimes as far as the stratosphere, where it can readily radiate into space.
So, doesn’t that make convection a negative feedback? Thunderstorms and hurricanes are really heat engines that act to cool the planet.
I presume GCMs take this into account when deciding water vapor is a positive feedback element.
Right?
Thanks. Given the proper sites and keywords to search, I have now found enough on the subject to keep me busy for a good while ; )
I really appreciate the help.
Michael Hammer:
I certainly agree with you about inconsistencies, but I think the standard response would be that your framework doesn’t capture the process correctly so can’t be relied on to draw conclusions about it. Personally, though, I think it would be valuable for the pro-IPCC folks to come up with a reasonable approximation of the process that is sufficiently simple(like yours is) for laypeople to access. I am not very impressed by arguments that its all in the GCMs somewhere. For all I know, no one individual knows how the GCMs actually come to their conclusions.
It doesn’t inspire confidence when you have authorities that are asserting mutually contradictory things (like WV is responsible for 75W/m2 of GH warming, but a 7% increase causes a 2W/m2 increase in heating).
Cheers, 🙂
“If we accept Miskolczi…”
And why would we ‘accept’ anti-physical nonsense? Seriously, haven’t you got that yet? Miskolczi’s ‘paper’ was anti-physical nonsense, and anyone who doesn’t realise that doesn’t understand physics.
I think that using such a simplified model to contradict the the results of various GCM’s doesn’t make sense. One such paper has already been published and rejected because the simplifications made were unrealistic. The author himself admits that his analysis is likely to be oversimplified.
http://www.ecd.bnl.gov/pubs/BNL-76939-2006-AB.pdf
http://www.realclimate.org/index.php/archives/2007/09/climate-insensitivity/
One problem is that a single time constant cannot be used to to characterize the effect of heat storage by the oceans. This is a complex process involving some heat retained in the upper part of the ocean and some heat transferred to the deeper parts of the oceans.
There is a totally different time constant associated with the albedo feedback mechanism.
When I look over the posts so far it seems that the predominant response is that the model is wrong and worthless because it is too simple. It amazes me that complexity is held up as a virtue and simplicity as a sin. Maybe thats what is wrong with big science today.
Consider this; many of you have talked about principle component analysis. For those not familiar with it let me explain briefly. The concept suggests that in any situation there will be a number of factors influencing the outcome. These are not all of equal importance. If we pick the most important and allow for that we should get the majority of the response. This is termed the principle component. If we then go on and allow for the second most important effect we should get most of the difference between our first estimate and the real response. This is the second component and so on. Rapidly we get to the point where the calculated outcome is close enough to the true outcome that the residual can be treated as noise. We get to this point without having to allow for every influencing factor. Just considering the few most significant is enough.
Principle component analysis is a very powerful way of reducing the complexity of real systems while sacrificing very little accuracy (and that in a controlled fashion).
IPCC have stated long and loud that CO2 is the trigger but its effect is amplified by positive feedback mechanisms. Of these IPCC have also stated very clearly that by far the most dominant feedback mechanism is water vapour. The second most dominant is cloud feedback. IPCC claim both of these are positive.
I model the trigger mechanism CO2 and don’t get within coee of the result IPCC claim. So I add what IPCC claim are the two most dominant contributary effects and I still don’t get within coee of what they claim.
OK Eric you claim my error lies in multiple feedback loops instead of one. Well I did think about that before I wrote the article and I also simulated a double time constant system (for those familiar with electrical engineering, a two pole system). Of course one has to show how this has relevance in the real world but lets ignor that for the moment.
The additions to the model are simple, here they are
A3 becomes the 2nd time constant user input field
B3=1/A3
G3=0
G4 = $B$3*F4 + (1-$B$3)*G3
change D4 to D4=C4 + $A$1*G3
Fill down columns D and G from row 4 to row 11
now you have three user fields to play with. I did this and I still could not come up with any combination which matched IPCC predictions and still gave sensible predictions beyond 2070 (ie: that did not equate to thermal runaway). Try it for yourself.
The point is that here is a model which simulates what IPCC claim to be by far the principle components of the AGW theory. The model output is not even close to what IPCC claim. That throws the entire AGW theory into question. Maybe the 3C is simply alarmist exaggeration. If so a more sober and realistic prediction may be less damaging to the AGW theory but such a prediction would not support the massive societal disruption being called for, nor would it support the claimed extreme time urgency.
On a separate but related subject, I am seeing a repeated approach of looking for any point that can be questioned in a contrary argument and using that as an excuse to dismiss the entire contrary argument. This is akin to reviewing a book and claiming it to be worthless because you disagree with how a word in line 23 of page 194 was spelt. Such an approach is absurd. To dismiss a contrary argument one must show a fundamental flaw in the data or reasoning.
Opps, in the postb above it should read
Fill down column D and G from row 4 to row 115 (not to row 11)
Michael,
I think you’ve overstated the IPCC projections of temperature for 2070. The IPCC do not predict future CO2 – they do a what-if analysis based on scenarios, and they list six primary ones. Your parabolic form, reaching 560ppm in 2070 corresponds best with their A1B. In the AR4 SPM, they list 2.8C as the best estimate rise from 1980-99 to 2090-99 (Table SPM-3).
My eyeball estimate from their Fig 10.4 is 2.2C from 2000 to 2070. Of course, that includes contributions from methane and other GHG.
Michael – of course an easier approach for a critique is to rock up to CSIRO at Aspendale and ask !
Mike says;
“On a separate but related subject, I am seeing a repeated approach of looking for any point that can be questioned in a contrary argument and using that as an excuse to dismiss the entire contrary argument. This is akin to reviewing a book and claiming it to be worthless because you disagree with how a word in line 23 of page 194 was spelt. Such an approach is absurd. To dismiss a contrary argument one must show a fundamental flaw in the data or reasoning.”
Well Mike, now you know how Ian Plimer feels. Its called reductionism hence my earlier comment to luke. It is what the AGW supporters do; actually they’ll use any connivance but your exposition of PCA is timely for this reason. It is amazing that Nick and others can flap-doddle around the the simple, PCA heart of AGW and say that the 3C increase for 2XCO2 is not set in stone; after all, its on p666 of AR4 and Hansen has stated it many times;
http://naturalscience.com/ns/articles/01-16/ns_jeh.html#Figure1
The utterances coming out of the AGW camp can only be said to be schizophrenic; we have moderate commentators like Nick understating the IPCC and model projections while on the other hand we have luminaries like Will Steffan saying, after Copenhagen, that the new predictions/astrological projections are much worse than the old ones; and Karoly writing letters to all the coal companies saying they’re going to have to close down; and Hansen calling the coal trains “trains of death”.
So, which is it boys; is AGW just a mild process or the end of the world?
I’ve had pretty good success simulating the IPPC forecasts and the GHG forcing temperature impacts with this formula:
Temp C (anomaly) = 4.053 LN (CO2 ppm) – 23.3
This gives the temperature C (anomaly from Zero rather than Kelvin etc.) and you can use any CO2 number you want. It gives the exact same values as the one Michael Hammer describes [And CO2 should be thought of as a proxy for all the GHGs rather than being the only GHG].
Over the whole spectrum of possible CO2 from 1 ppm to 600 ppm you get an interesting Logarithmic chart like this (I’m using the original Global Warming Model’s projections here instead of the more recent projections which are a little lower and then it is compared to the actual temperatures to date).
http://img216.imageshack.us/img216/9652/logwarmingillustratedkn7.png
One problem with assuming this simple formula is like a climate model is that they also are building in large negative forcings like Aerosols (which as high as -0.6C now) into the models as well.
Here is how GISS Model E looks when you split the GHG component out from the Other Forcings (1880 to 2003).
http://img183.imageshack.us/img183/6131/modeleghgvsotherbc9.png
And here is what all the different forcings in GISS Model E work out to in terms of temperature impact from 1880 to 2003.
http://img509.imageshack.us/img509/8388/modeletempimpactst.png
[Yes, they are just making this up to balance out to the actual temps measured to date.]
Hansen even said recently that they more-or-less just pulled the (-0.6C) Aerosols forcing out of hat. And he was NOT kidding.
http://img58.imageshack.us/img58/855/modelaerosolsforcingp.png
“When I look over the posts so far it seems that the predominant response is that the model is wrong and worthless because it is too simple. It amazes me that complexity is held up as a virtue and simplicity as a sin. Maybe thats what is wrong with big science today.”
What’s that saying? Things should be as simple as possible, but no simpler? Your drive for simplification has created a model that is too simple to be used to evaluate the research behind and implementation of, the GCMs.
Model ‘E’ is out there in the public domain, and it is much more complex than your model, but also much simpler than the state of the art. Perhaps you should start with that?
Here is an abstract from a very early model, and all the factors they take into consideration back then.
http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=TRD&recid=A7810666AH&q=author%3A%22Arakawa%22+intitle%3A%22Computational+design+of+the+basic+dynamical+processes+of+…%22+&uid=1489924&setcookie=yes
[quote]
The 12-layer UCLA general circulation model encompassing troposphere and stratosphere (and superjacent ‘sponge layer’) is described. Prognostic variables are: surface pressure, horizontal velocity, temperature, water vapor and ozone in each layer, planetary boundary layer (PBL) depth, temperature, moisture and momentum discontinuities at PBL top, ground temperature and water storage, and mass of snow on ground. Selection of space finite-difference schemes for homogeneous incompressible flow, with/without a free surface, nonlinear two-dimensional nondivergent flow, enstrophy conserving schemes, momentum advection schemes, vertical and horizontal difference schemes, and time differencing schemes are discussed.
[/quote]
I would suggest your model needs to incorporate all these factors, at least.
You’ve never had to make a climate risk decision in your life Cohers. Legal offices tend to be air-conditioned.
And you want “certainty”. There isn’t any.
There’s physics, empirical data, and modelled outcomes.
Climate change outcomes could be mild to wild. Depends on your POV.
If you were more in tune with current climate risks we’re mal-adapted to, you’d have a much more constructive view of determining the truth vis a vis knowing “it’s 100% all wrong and a neo-marxist plot”.
“You’ve never had to make a climate risk decision in your life Cohers. Legal offices tend to be air-conditioned.
And you want “certainty”. There isn’t any.”
Oh yes there is. Lawyers are certain they can win the case for you. 😉
yeah, good work as usual Bill; the problem for guys like Mike is that when they try to critique AGW modeling they cannot adjust for the inherent contradictions of that modeling. Hansen and the models have aerosols as a -ve forcing or cooling and this is essential for the dimming of the 40’s and up to the 90’s. But AGW orthodoxy also has aerosols as a +ve forcing or heating mechanism;
http://www.nasa.gov/topics/earth/features/warming_aerosols_prt.htm
Just to clarify a point about Hansen and the variations in model projections; Hansen in fact is worsening his predictions but enlongating the time span;
http://arxiv.org/abs/0804.1126
So, now the ECS occurs within a period of 1500 years and will be 6C.
“You’ve never had to make a climate risk decision in your life Cohers. Legal offices tend to be air-conditioned”
That’s quite unreasonable luke; my beach house will, if AGW is correct, be inundated shortly; so I regard that as a climate risk decision. And I grew up on a farm; each crop planted was a climate risk decision. And for the umpteenth time I’m telling you, I’ve got an open mind on the subject but don’t ask me to turn off the crap meter. Speaking of which, thanks for the latest Trenberth paper, “Global warming due to increasing absorbed solar radiation.” This paper is a template of the confusion in AGW ranks about the essential climate paremeters, in this case clouds. I give a summary of it over at Niche in the discussion about poor old Miskolczi’s Tau, so brutally ravaged by Steve recently 🙂
Now you know Dad made all those decisions.
As for the imminent inundation of the beach house – I doubt it – and you know better.
And yes I did give you that paper. For others.
Global warming due to increasing absorbed solar radiation
Kevin E. Trenberth
National Center for Atmospheric Research, Boulder, Colorado, USA
John T. Fasullo
National Center for Atmospheric Research, Boulder, Colorado, USA
Global climate models used in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) are examined for the top‐of‐atmosphere radiation changes as carbon dioxide and other greenhouse gases build up from 1950 to 2100. There is an increase in net radiation absorbed, but not in ways commonly assumed. While there is a large increase in the greenhouse effect from increasing greenhouse gases and water vapor (as a feedback), this is offset to a large degree by a decreasing greenhouse effect from reducing cloud cover and increasing radiative emissions from higher temperatures. Instead the main warming from an energy budget standpoint comes from increases in absorbed solar radiation that stem directly from the decreasing cloud amounts. These findings underscore the need to ascertain the credibility of the model changes, especially insofar as changes in clouds are concerned.
Received 28 January 2009; accepted 19 March 2009; published 14 April 2009.
Citation: Trenberth, K. E., and J. T. Fasullo (2009), Global warming due to increasing absorbed solar radiation, Geophys. Res. Lett., 36, L07706, doi:10.1029/2009GL037527.
“This paper is a template of the confusion in AGW ranks about the essential climate paremeters, in this case clouds. ”
You refuese point blank to take the honest approach, and respect that fact that science research into AGW tells us explicitly where the knowledge in climate understanding is lacking.
This hyprocritical and self serving attitude to the scientists is obscene.
They are damned for being insular and smug, in it just for the research grants, to destroy the capitalist system, and any number of the rest of the lunatic, paranoid conspiracy theories.
Yet they tell us exactly what they are researching, and why, and where their areas of understanding are lacking. When they do the reseach, it’s not because they trying to improve their understanding of the climate, but it’s just an indication of their ‘confusion’.
Yet all along, no ‘skeptics’ will admit to their ‘confusion’, when your attempts, Cohenite, at explaining theory, would have the average scientist spitting their coffee over their screen, with much the same response as I imagine you would have at the poor bastards who get up to do their own defense in court.
OK, I’ve set up and run the model – the version as in the original post. It seems to be a reasonable model, as far as it goes. But I can’t see a major inconsistency with IPCC projections.
First, you should remember that the IPCC projects on the basis of all GHG, not just CO2. According to Fig SPM2, forcing to date from CO2 is 1.6 W/m2 (midrange); from CH4 is 0.48, and other industrial GHG emissions, another 0.5. Accounting for these would add about 60% to the temperature discrepancy.
As I mentioned above, if you look up the IPCC projection for scenario A1B, which is close to that here, the increase is about 2.2C from 2000 to 2070; maybe 2,7 from 1959 to 2070. I’m easily finding increases in the spreadsheet of up to 2C. Allowing for other GHG easily makes up the difference.
Michael hammer “…for the sake of this post I indicated I am using their data. Why? because if I used data I think is closer to the truth that would be used as the excuse why I get a different outcome. By using their data I overcome that issue and my point here is to show that even using their data an 0.5C rise by 2008 does not fit with a further 3C rise by 2070.”
Michael…thanks for the explanation. It just seem that you are paying lip service to their pseudo-mechanisms for heat production by using a model that suggests ‘real’ positive feedback is at play. I think the focus should be on revealing the bad physics in the IPCC arguments. Then again, how many real physicists took part in the IPCC reviews, or were asked to take part?
Gordon
Roy Spencer, Lindzen, Michaels, all believe there is a greenhouse gas effect.
http://www.drroyspencer.com/global-warming-101/
They just disagree on the extent of warming that will be caused by CO2 levels increasing. You are flogging a dead horse. Your problem is you can’t understand how the ‘greenhouse gas’ effect works.
Hi Nick; As I think you already know, I have considerable regard for your rational science oriented approach even if our views are on opposite sides of the debate. Still interested to get together off line if you are.
With regard to the model, I agree there is no difficulty at all in achieving 3.5C rise between 1959 and 2070 or 2.8 or any other reasonable number. That is not the issue. What is at issue is achieving that sort of number by 2070 TOGETHER with 0.5C rise in 2008. So why is this important? Because if the projection for 2008 does not come close to meeting the experimental value, then the theory must be considered flawed which means no reliance can be placed on the 2070 projection. If the model is adjusted to match the 0.5C rise in 2008 then the 2070 projection is much lower and again the 3C projection is not supported.
With reagrd to the IPCC claims. What I read was IPCC were claiming a business as usual scenario would lead to CO2 rising to 560 ppm by 2070 and that that would lead to a temperature rise between now and 2070 of 3C. Actually a range of possible temperatures with 3C the “most probable”.
Gordon; we appear to approach the science behind the AGW issue slightly differently. Clearly we share the same overall opinion that the AGW alarmism is unjustified but we may not agree on every detail. I am working from the perspective of spectroscopy and analysing where that leads. I am not claiming there is zero effect from rising CO2. My analysis suggests that some warming will occur but the degree is far less than claimed by IPCC and not enough to worry about. Maybe your view is correct but I cannot defend a perspective not supported by my analysis.
Just to outline where I stand. I am concerned about our reliance on fossil fuel. Specifically I think human society has outgrown reliance on chemical energy and needs to develop new energy sources. However I most emphatically do not think the problem can be solved by economising (although reasonable economising is justified – waste is never justified). Nor do I think that the touted solutions of wind and solar in their current forms are in any way adequate solutions either in the short term of the medium term. My opposition to AGW lies in that I fear an hysterical focus on immediate solutions through these energy forms and abandonment of fossil fuel will bleed resources to such a point that society might find itself unable to come up with the real solution. We have time both from the point of view of fossil fuel availablility and because I think AGW is dramatically exaggerated to find a real solution but we need to start looking intensively. To me this is a far far better use of the money currently wasted on AGW abatement.
Societies move forward or they collapse and disappear. I would like us to move forwards so as to give our children less limited opportunities than we have. The lessons from history of times when that did not happen are chilling.
end of lecture; with apologies.
I’m probably going to get excoriated for the following, but the statement “Roy Spencer, Lindzen, Michaels, all believe there is a greenhouse gas effect.” isn’t scientific.
Scientific laws are not dependant on a belief in so and so. They are determined by the ruthless domination of measured FACT – and like it or not, despite an ever increasing level of CO2 in the Earth’s atmosphere, the Earth’s seems to be cooling.
There is one other issue that has always troubled me as a physical scientist – the confusion between the chemical composition of the Earth’s atmosphere, and its physical behaviour.
Sensu strictu the Earth’s atmosphere comprises a gas phase of variable chemical composition, an aerosol phase (suspended solids) and a liquid phase of clouds.
Given the association of electrical activity with clouds, and let’s be brutually honest, the Earth is, when all said and done, an electrically active body immersed in the plasma of space, it’s surprising that climate science continues to restrict its deliberations to the Victorian Era mechanical model.
The Earth’s present cooling is nothing more prosaic than the result of a reduction of galactic electrical power to the Sun. What causes THAT, is entirely another matter, and not germane here.
“Sensu strictu” 😉
“Still interested to get together off line if you are.”
I find it very educational online.
“Because if the projection for 2008 does not come close to meeting the experimental value, then the theory must be considered flawed which means no reliance can be placed on the 2070 projection.”
I have pointed this out to many people before, but they usually ignore the point. If you look at the temperature record, there are several times that dips like 2008 have occurred, there is nothing remarkable about it. Each time, the gradual climb higher resumes. Is that or is it not the case.
In regard to the “Saturated Gassy Argument”, the model assumes a logarithmic function for the direct temperature response to a rise in CO2 levels. The “SGA” is not a component of the model, but an additional component you have left out. The logarithmic response is due to the pure physics of adding more gas to the existing mix, the more you add, the less the effect. When you read the “SGA”, there is an additional forcing beyond the pure logarithmic response. You previous response to me indicates you did not grasp that. It is not a component of the logarithmic response.
“My opposition to AGW lies in that I fear an hysterical focus on immediate solutions through these energy forms and abandonment of fossil fuel will bleed resources to such a point that society might find itself unable to come up with the real solution. We have time both from the point of view of fossil fuel availablility and because I think AGW is dramatically exaggerated to find a real solution but we need to start looking intensively. To me this is a far far better use of the money currently wasted on AGW abatement.”
If AGW theory is right, we don’t have any time. Even if we stop adding CO2 now completely, temperature will still rise. If we stop completely in 50 years time, temperature will still rise.
The Greenhouse Warming has been much less than expected to date. The Hansen/IPPC formulae are off by more than 50% to date.
What are the possible explanations:
– Water vapour feedback is not occuring. True. All the available data shows Specific Humidity is a near constant entity (constant as in flat as a board). There are very, very slight trends at differnt levels of the atmosphere but on average it is flat and it far off the predictions of the models.
– Aerosols are cooling us down. Probably False. There are Aerosols but if anything, they seem to have a positive rather than negative impact. The NH (where the aerosols are) have warmed faster than the SH. South Asia temps are rising rapidly right now due to the brown cloud, just like southern California did.
– The Oceans are absorbing some of the increased energy so it is not warming at the surface as much, the deep oceans are warming instead. False. The latest data shows the Ocean Heat Content has not increased in 5 years so the surface is effectively receiving all the forcing it can get. We are already at equilibrium (in the last five years anyway).
So that only leaves – The models and the theory are wrong (and they are also wrong about water vapour, aerosols and ocean thermal response lags).
Just to add a bit to the point that IPCC claims that there has been ~ 1.6W/m2 of anthropogenic forcing. Assuming that number is true, and Dessler claim about the 2W/m2/deg C of WV forcing were valid. We should have experienced at this point somewhere around 3.2W/m2 or about 0.85C as well.
The point is that WV forcing should happen pretty quickly in a few months to a year at the outside. If there are other feedbacks that take longer to work through the system, that shouldn’t materially affect the amount of heating we should have seen from water vapor feedback.
Now, if anything, 0.85C overstates the amount of heating we have seen during the industrialization of the last couple hundred years(it would assume amongst other things that there has been no natural warming at all).
So far, IMO, there is no justification for any other long term feedback processes that would materially increase the temperature. If CO2 +WV can easily explain all the warming(assumed arguendo), why postulate the existence other large unmeasurable undetectable feedback processes?
Could it be that if one just went with just WV +CO2, we would expect warming this century of only about +/- 1C(and some people think that this just isn’t enough)?
Cheers, 🙂
Bill Illis,
Piling on your “accepted knowledge is wrong meme,” a recent paper casts doubt on the monolithic thermohaline circulation. Seems it tends to spread out a bit rather than being a bottom of the ocean subway!!!
http://www.nature.com/nature/journal/v459/n7244/full/nature07979.html
Whoda thunk?!?!?!?!?!?!
SJT,
” If you look at the temperature record, there are several times that dips like 2008 have occurred, there is nothing remarkable about it. Each time, the gradual climb higher resumes. Is that or is it not the case.”
Yup, it returns to its climb into the next ICE AGE!!!
I thought you warmers believed in REAL CLIMATE, not those short WEATHER blips less than 100,000 years long!!
So, have you figured out how CO2 causes Sudden Stratospheric Warming yet??
HAHAHAHAHAHAHAHAHAHAHA
All right SJT; you don’t like my comparison with 2008; so let me rephrase it. If one uses parameters for the model which show an additional 3C rise between now and 2070 then the entire model output from 1959 to 2008 is in extremely poor agreement with the experimental record. Specifically we should have seen much more warming by now. If you think that this might also be a short abberation then may I point out it represents the entire data set on which hysterical AGW is based!
My comment about getting together off line was not directed to you as was clear from the post.
With regard to logarithmic response, I think it is you who have misunderstood. I invite you to integrate the Voigt rpofile for various concentrations. My findings and hence my prediction to you is that if you do that in isolation you do not get a logarithmic response! HOWEVER if you also assume the relationship I derived in my very first posting ie: fractional energy retained = n-1/n where n= total absorbance you will find the response then becomes logarithmic.
I completely agree with Shawn, the water vapour response will have a very short time constant. However the water vapour response depends not on CO2 but on temperature and IPCC continuously claim that this has a long time constant due to the thermal mass of the oceans. Pesonally I think the time constant for warming the deep oceans may well be very long but the time constant of ocean impact on climate is not very long at all because of the presence of the thermoocline. This is a very steep temperature gradient about 100 meters or so below the surface. It represents a boundary between the well stirred upper layers and the close to static deeper ocean. Only the ocean surface temeprature is significant for climate because it is that which controls water evaporation. As experimental evidence, can I point out that in winter ocean water is extremely cold – much too cold for swimming yet in summer the water is very noticeably warmer. If it can change significantly in 6 months it cannot have all that long a time constant.
To preempt any claim that ice albedo has a long time constant, can i point out that the greatest impact is ice on water since bare water has a very low albedo. As we keep hearing in regard to the arctic, the area of ice covered water changes markedly summer to winter. Indeed environmentalists have been predicting that the arctic ice on water will disappear completley over summer. If that can happen then clearly the time constant is less than 6 months.
With regard to water vapour feedback, is it positive or negative. I have been doing some calulations about that as well. What I find is that the direct effect of water vapour is positive but more water vapour leads to more precipitation and precipitation comes from low clouds so more more water vapour means more low cloud mass and low cloud this provides exceptionally strong negative feedback. Vastly stronger negative feedback than the direct effect of water vapour. Thus the total effect of water vapour is strongly negative.
This also suggsets that if cosmic rays do modulate cloud formation then Svensmark’s theory has a high probability of being correct. The Wilson Cloud chamber experience used for decades very strongly predicts that cosmic rays must modulate cloud formation (by the way the Wilson Cloud chamber has been used for decades by nuclear physicists so its performance and operation mechanism is totally beyond dispute). Further corroborative experimental evidence is the close correlation between solar activity and temperature. Also measurements of albedo which show that it does change and that the changes do seem to correlate with measured temperature. Measurements of the cosmic ray flux which shows that it also changes significantly with time. These experimental findings represent very strong experimental support for the theory – a level of support I am sure the AGW proponents would claim as cast iron proof beyond any possible dispute if it supported their position.
SJT, your last paragraph again invokes the precautionary principle so beloved of environmentalists. I have earlier commented that this is a very dangeous and unjustified principle. Let me now point out a ramification. If AGW is right and we do not stop emitting the worst outcome is we might see a further 2-3C rise by 2070 returning us to about the conditions of the medieval warm period. This was a period of high prosperity with excess capacity as evidenced by the extremely rich architectural and artistic legacy. At worst it might cause some migration of species (if we believe the scare stories), increased food production both due to warmer temperature and higher CO2 levels, a reduction in cold related deaths partly but not totally offset by more heat related deaths (the records are clear on that) and so on. If AGW is wrong and we pursue the course it advocates we may find outselves without an energy source and no resources to develop a new one which would doom our society to extinction.
I know which scenario I would prefer and I am 100% confident that the vast majority of citizens will agree with me when brought face to face with the consequences.
“My comment about getting together off line was not directed to you as was clear from the post.”
I know, but I meant the exchanges between the two of you are highly educational, that’s why I would like to see them online.
“At worst it might cause some migration of species (if we believe the scare stories), ”
The migrations are happening already, it’s not a matter of might. Not all species have that option by a long way.
“SJT, your last paragraph again invokes the precautionary principle so beloved of environmentalists. I have earlier commented that this is a very dangeous and unjustified principle. Let me now point out a ramification. If AGW is right and we do not stop emitting the worst outcome is we might see a further 2-3C rise by 2070 returning us to about the conditions of the medieval warm period. This was a period of high prosperity with excess capacity as evidenced by the extremely rich architectural and artistic legacy.”
I believe you are out by an order of magnitude, if you refer to an approved skeptic, Loehle.
http://www.ncasi.org/Publications/Detail.aspx?id=3025
“This was a period of high prosperity with excess capacity as evidenced by the extremely rich architectural and artistic legacy.”
How utterly Euro-centric, myopic and soooo predictably denialist !
Get hold of Brian Fagan’s book – the Great Warming and enjoy some mega-droughts.
SJT; as regards your 9:09 post. I owe you an apology. Clearly i misunderstood what you were getting at. I will bear your comment in mind and thanks for the ongoing interest.
Luke, clearly we see things differently and I accept that you object to my “Euro-centricity” however we seem to be moving off topic.
The question is still, why does this simple model give such different results from IPCC predictions. The comment has been made that there are many time constants involved. In terms of water feedback through direct water vapour, clouds and ice I don’t see that. I can see that all three might be governed by temperature (indeed I would expect them to be), but then I have allowed for that. I would expect all three to track temperature with very short additional time constants otherwise. – neglegibly short in the time frame we are considering. Humidity varies significantly day to day and even within a day, as do clouds. I have read comments that the cycle from evaporation of a water molecule to it falling as rain is about 2 weeks. If so, that more of less sets the time constant. No doubt you will tell me this data is wrong and enlighten me. As regards ice, since the Arctic ice level swings very markedly between summer and winter that again suggests that it tracks temperature with a very short time constant. So where do the multiple time constants come in?
If AGW is right and we do not stop emitting the worst outcome is we might see a further 2-3C rise by 2070 returning us to about the conditions of the medieval warm period.
Michael, you know absolutely nothing about climate models and even less about climate history.
i don t think that this is a good combination for making post like you do. it makes you look very stupid.
please point out any reconstruction, that shows the MWP to be nearly 3°C above temperature today.
i am waiting patiently …
“please point out any reconstruction, that shows the MWP to be nearly 3°C above temperature today.”
There you go sod, straight from the gelding’s mouth;
http://www.climateaudit.org/?p=3072
“There you go sod, straight from the gelding’s mouth;”
That doesn’t support your claim at all. It is a much better match for Loehle’s warming of < 1C.
even the utterly insane version of this graph that was posted by [Beck](http://www.realclimate.org/images/beck_modified_large.jpg) does not give MWP 3°C warmer than today.
you might want to try again…
” min kronikk sier jeg at temperaturen for 1000 år siden var om lag på nivå med det vi nå har. Jeg brukte en figur fra rapporten Surface Temperature Reconstructions for the Last 2000 years Report in brief, The National Academy of Science fra 2006.” – Norwegian climate scientist
Roughly translated: In my chronicle I stated that the temperature for 1000 years ago is on the same level as we have currently. I used the graph from the report ” Surface …….” ( se above)
yes, that’s right little will, Loehle did find only about 1C difference didn’t he? Some other MWP studies did find a bit higher though;
http://www.co2science.org/data/mwp/quantitative.php
The thing is, there is no doubt that MWP temps were higher and certainly LIA temps were lower than today because we not only have reliable dendroclimatic studies [as opposed to mann’ effort] but other archeological, social and literary records to prove it. Anyway, that’s quite enough from the peanut gallery; you guys are the ones pushing the doomsday button so you put the evidence.
“. Anyway, that’s quite enough from the peanut gallery; you guys are the ones pushing the doomsday button so you put the evidence.”
Moving the goal posts again. You must get tired doing that. The topic is MH’s model, and his claim that the MWP was 3C warmer than today.
Michael,
I think I’ve found an error in what you are doing. You are expressing the CO2 driver as relative to preindustrial ppm, which is 280. So in 1957 you already have a substantial driver which should translate into temperature. But you add a water amplification relative to the previous years temp, which is 0. This isn’t right.
The simplest way to fix it is to use log(B4/315) in C4. That is, you should use the starting CO2 level corresponding to the zero temperature level that you have chosen. That means that the CO2 forcing is amplified with a consistent water amplification.
I find then that with, say, A1=.281 and A2=7, the 2008 temp is 0.53C and the subsequent rise to 2070 is 1.85C. Given that the IPCC prediction on the A1B scenario is about 2.2C, and you aren’t accounting for CH4 etc, while they are, I think that is a good correspondence.
I think there is also a problem with your implementation of the time constant, since the answer goes to infinity with short time constants, and I don’t think it should. But it’s been a busy day here, and I haven’t had time to track it down.
yes, that’s right little will, Loehle did find only about 1C difference didn’t he? Some other MWP studies did find a bit higher though;
Loehle found nothing of that sort. instead his paper, after massive revision for blatant errors, comes to this conclusion:
Even adding this rise to the 1935 reconstructed value, the MWP peak remains 0.07 Deg C above the end of the 20th Century values, though the difference is not significant.
(Loehle 2008, page 98)
http://www.ncasi.org/Publications/Detail.aspx?id=3025
sorry, you were wrong by a factor of about 20!
and even that number by Loehle is based on a pretty bizarre method, modern temperature is cooled by a 30 year smooth. “now” (as seen by Loehle) includes temperature from the 70s…
http://www.co2science.org/data/mwp/quantitative.php
CO2science is perhaps the worst source on the net. please provide links to those 3°c studies, and they will fall apart immediately.
i am waiting patiently.
The thing is, there is no doubt that MWP temps were higher
the majority of evidence says it isn t. even the Loehle paper shows that it is at best similar, and most likely it is warmer today.
SJT; you talk about moving the goal posts! The topic is what if anything is wrong with the model – period! Forgive me if I am mistaken but your comments so far are giving me the impression that you find this a disturbing topic and would like to change the subject. Non the less, the model is the subject of this thread.
Nick, I can rely on you to look at the issue objectively. I understand what you are claiming but if you want to claim this as an error I think one needs to do it the other way round. Start the simulation at 1900 at the preindustrial level because this is the reference point on which the temperature rises are based. However I am very confident that this will not remove the conflict. The issue you point out only produces an initial transient which disappears within about 1 time constant. I do not believe it in any way invalidates the result. Non the less, it is pointless debating this when it is so easy to find out exactly. I will look up some data for CO2 levels between 1900 and 1959 and start the simulation from 1900. I will post the results on this thread as soon as I have them.
With regard to your numbers; I changed C4 to conform to your suggestion and ran your numbers for A1 and A2. The output was nowhere near what you gave. Are you sure you used A1 = 0.281? that would represent very low feedabck from water vapour. Should it be 2.81 instead? With A1=2.4 and A2=7 using C4=log (b4/315) I got 0.5C in 2008 and 1.86C in 2070 which is a rise between now and 2070 of 1.36C – a far cry from the 3C that the 4th assessment report claimed as the most probable rise for that period.
The fact that your result went to infinity with short time constants suggests to me very strongly that either there is an error in your formula for column F or that your water vapour feedback gives an overall positive feedback of slightly above 1. Consider the formula I gave for the time constant. At steady state, the gain will be exactly one as it should be so it can’t cause runaway. I have used this IIR filter countless times and I did check it again this time specifically to ensure the formula I gave resulted in the correct response. Given that there seems to be some discrepancy between your A1/A2 numbers and your outputs plus runaway with a low value of A2 I suspect your formula for column F has an error.
Anne; I am disappointed that you believe the temperature was steady for the last 1000 years. The evidence for the existence of a medieval warm period and the little ice age is so overwhelming that I would have thought it totally beyond dispute. I know Michael Mann tried to expunge it but his work has been absolutely discredited.
Sod; you claim with great certainty that I know nothing about climate models and that I simply make myself look stupid. However, I point out that this thread is specifically about a climate model I created. To make your claim with such certainty you must know a lot about climate models so please tell me what is wrong with the one I posted. And please be specific not just a vague reference to outside “authority”. Such references are not enlightening.
Michael,
You are right, I mistyped. A2 should have been 2.81, and I think your results are then the same as mine. But if you’re claiming to refute the IPCC, you really should properly source your claim that they say 3C is the figure. I’ve given my source for saying that it should be 2.2C.
The key to the discrepancy issue is that you should use the same reference point for temperature and CO2. In other words, if you use a year when CO2 was 280, that should be zero temp. So it is better to use 1959 (or 1958) as the reference year.
On the time lag, another reason why I think your treatment is not right is that setting A2=1 makes cols E and F exactly the same. There shouldn’t be anything special about a time const of 1 year – and I think this equality (E=F) should be true if the time constant is zero. I don’t think it invalidates your process – it just affects the interpretation of what A2 means. I suspect it is (timeconstant+1).
BTW, I agree with sod on the MWP issue. +3C is a lot of warming.
“SJT; you talk about moving the goal posts! The topic is what if anything is wrong with the model – period! Forgive me if I am mistaken but your comments so far are giving me the impression that you find this a disturbing topic and would like to change the subject. Non the less, the model is the subject of this thread.”
It was you who raised the topic of the temperature rising 3C during the MWP. I can’t find any evidence for it, not even from an approved ‘sceptic’ like Loehle. If you want to drop that diversion and concentrate on the model, so be it.
Michael,
Correction – your results are not the same as mine. I got 2.44 in 2070, so the difference (2070-2008) is 1.85.
A bit more on the reference point issue – why should F3 be set to zero? You may be thinking that it makes no real difference – if you set it to 1, you just raise all the temperatures by 1. But try it – it isn’t so. You’re making a real choice. So what should F3 be? Again, I say, it should be the temp in 1958, relative to the temp whenever CO2 was 280 (or whatever other reference value you choose, which is why I suggest 315).
“Luke, clearly we see things differently and I accept that you object to my “Euro-centricity” however we seem to be moving off topic.”
No Michael – you just ducked it. The MWP was not universally wonderful.
Mega-droughts in America, China and Africa.
OK Nick, I found some data for CO2 prior to 1959. The overall equation 0.01*(year-1900)^2 – 0.05*(year-1900) + 280 seems to fit the entire co2 record pretty well – ie: within a few ppm. 1959 came out as 312 cf 315, 2069 came out at 556, 2008 came out at 391. Not quite as well as the previous fit but still a very good fit.
So to modify the model change A4 to 1900
change B4 to 0.01*(a4-1900)^2-0.05*(A4-1900)+280
fill down now to row 174 which should correspond to 2070
I did all this and as I expected the differences are even worse.
for A1=2 A2=23 temp in 2008 is +0.5 in 2070 +1.38 rise 2008 to 2070 0.88c
for A2=3 A2=31 temp in 2008 is +0.51 in 2070 +1.61 rise 2008 to 2070 1.1C
for A2=3.5 A2=35 temp in 2008 is 0.50 and in 2070 1.72 rise 2008 to 2070 1.22C
for A2>3.7 thermal runaway occurs with zero forcing.
About your point that the value of A3 matters. A3 is an initial condition. Setting it to 1 does not raise all temperatures by 1C. What it does is to inject a 1C transient at the start. This will decay back to the equilibrium value over time – 67% will decay in 1 time constant and so on. If model outputs of interest are several time constants from the start it makes no difference. On the other hand if one is interestied in values close to the start of the run it does indeed make a difference. However with the above change that becomes academic since 1900 is the zero reference temperature.
By the way, this update introduces yet another paradox because the temperature versus time profile over the 20th century is substantially different to the actual measured profile.
“By the way, this update introduces yet another paradox because the temperature versus time profile over the 20th century is substantially different to the actual measured profile.”
That would be because the modelers use much more sophisticated models that take into account other forcings, such as particles and solar variation.
This is a good place to start.
9.4.1.2
http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch09.pdf
Quite possible SJT and given the size of the discrepancies it implies that these other forcings such as solar actually contribute the dominant component. I have no problem with that scenario. So why the focus on CO2?
“Quite possible SJT and given the size of the discrepancies it implies that these other forcings such as solar actually contribute the dominant component. I have no problem with that scenario. So why the focus on CO2?”
You are putting the cart before the horse. There is no ‘focus’ in the models, which are used to analyse the current warming. CO2 is the result they return. Other climate factors such as solar aren’t providing the same level of forcing that CO2 currently is. I have no doubt that will change over time. The focus, of course, is on what is currently happening.
By the way, this update introduces yet another paradox because the temperature versus time profile over the 20th century is substantially different to the actual measured profile.
why would your simplified model perfectly match the historic profile?
or, put the other way round: you make it match a significant part of the past, and you can finally call it a “climate model”!
Michael,
I’ve figured a bit more about your model. You’re solving this differential equation, with t in years:
RC dV/dt = RI + (aR-1)V
R=0.27, RC=B1= time constant, a = A1 = feedback, V = temp (col F), I = col C = CO2 driver
I’ve written it that way to show the analogy to a parallel RC circuit, driven by I. You can also write it as:
rC dV/dt = rI – V where r=R/(1-aR)
This reflects the increased impedance due to positive feedback. Note that the effective feedback rC is also increased. This is important.
It means it doesn’t work very well when a gets up towards 3.5. The effective time constant is centuries – nothing is close to equilibrium.
It gives a bit of insight into the initial condition. The initial V corresponds to the initial charge on the capacitor, which will depend on recent history. By going back to 1900, you can say not too unreasonably that prior to that I=0, so V=0.
I think the results that don’t correspond well are, as SJT says, just a result if the complexity of the real world that GCM’s model. There are other GHG’s and aerosols. There are volcanoes and other cyclic processes. I think the dominant one here is the aerosol burst with the pollution of the 50’s and 60’s, which caused a marked N hemisphere temperature dip. 1959 is right in the middle of that.
Lucia’s model Lumpy is similar to yours but uses a much more comprehensive driving function. It gives a good correspondence, and you can see from the input that CO2 plays a major role, but there are other factors.
I’d like to ask again for a reference on your claimed IPCC increase. It really weakens your case if you build a model to test the IPCC projection, but when it comes to what the projection actually is, you don’t even say which of the six IPCC scenarios your claimed projection relates to.
“effective feedback RC” – I meant “effective time constant RC”
Michael Hammer “I am not claiming there is zero effect from rising CO2. My analysis suggests that some warming will occur but the degree is far less than claimed by IPCC and not enough to worry about”.
Michael…I should point out that John Christy of UAH has been of the same opinion, that CO2 ‘should’ warm the atmosphere but the data from his satellites are not showing it. Neither is the decadal data from the satellites, which shows no net warming in 10 years and a slight cooling trend since 2005. In the 2008 study by Keenlyside et al, they acknowledged the flattening of the warming trend, but being AGW advocates, they blame it on the AMO and expect it to resume by 2016.
I’m not arguing that no warming is coming from GHG’s, I’m arguing with the mechanism, which as G&T claim, is not backed by physics theory and contravenes the 2nd law. In other words, the IPCC does not have a scientifically based argument, only computer model insanity. Akasofu has pointed out that we have been recovering from the LIA and the IPCC did not allow for that natural warming in it’s figures. You haven’t allowed for it in yours either.
Tsonis et al, in 2008, revealed that the oceanic circulation systems like Enso, the AMO and the PDO can operate together to produce warming. An El Nino increased global temperatures as much in 1997 as what the IPCC claim CO2 has done in a century. My argument, based largely on the paper by G&T and the textbook by Craig Bohren and Clothiaux, is based on the extreme rarity of CO2 as a gas in the atmosphere. No one has explained how it ‘traps’ heat or behaves like a blanket. If IR radiation from the surface is treated as a wave, rather than as photon emission, given the inter-atomic spaces between CO2 molecules, there’s no way CO2 could trap enough heat to make a difference.
That’s especially true given the paltry percentage of ACO2 wrt natural based CO2. If pre Industrial levels of CO2 was 270 ppmv it was all natural CO2. The IPCC has assumed we have contributed more than 100 ppmv to that level and that all of the ACO2 is part of the 380 ppmv today. That’s one of their more stupid claims since records of atmospheric density of CO2 was not kept prior to 1950. The rest is based on proxy data and we saw how Michael Mann and the IPCC abused the use of proxy data. In fact, anyone using proxy data as the basis for such an important theory is not dealing with a full deck.
Also, even today, GISS has admitted they cannot account for 50% of ACO2 emissions. On the IPCC graph in AR4, WG1, Chapter 7, Figure 7.3, the IPCC gives a 20% error for their estimates of CO2 emissions. That’s like saying they have no idea what the pre Industrial level were. Given the evidence by Jaworowski, that ice core proxies are 30% to 50% unreliable due to compression in deep ice and water introduced by drills, as well as Beck’s revelation that CO2 levels have been ‘measured’ at over 400 ppmv in the 1940’s, I’d say the CO2 warming theory is dead meat.
“Michael…I should point out that John Christy of UAH has been of the same opinion, that CO2 ’should’ warm the atmosphere but the data from his satellites are not showing it. Neither is the decadal data from the satellites, which shows no net warming in 10 years and a slight cooling trend since 2005. In the 2008 study by Keenlyside et al, they acknowledged the flattening of the warming trend, but being AGW advocates, they blame it on the AMO and expect it to resume by 2016.
I’m not arguing that no warming is coming from GHG’s, I’m arguing with the mechanism, which as G&T claim, is not backed by physics theory and contravenes the 2nd law. In other words, the IPCC does not have a scientifically based argument, only computer model insanity”
So how are you going to reconcile your belief in GHGs causing warming, and your disbelief that the physics is correct. You accept it happens, as Christy and others say it does, but you don’t accept the mechanism. How is it happening then?
Gordon: I asked you for a page reference to Bohren and Clothiaux’s book in a previous Hammer thread, but I don’t think you provided it. I’ll take up the issue again. I have their book right in front of me, as I write. What they say (p. 37) is that analogies to “blankets” are incorrect, because blankets act to suppress convection (just as a greenhouse suppresses convection). But I think you are attacking a straw man if you suppose that assertions about “CO2 blankets” are the foundation of the IPCC case. Go back to p. 34 in Bohren and Clothiaux: global warming (they use the term) can be interpreted EITHER as the result of “closing the absorption window” or as the result of increased emission (due to higher gas emissivities).
You make an assertion about the “extreme rarity” of CO2 in the atmosphere. This is just a subjective term, devoid of significance. Of the more abundant gases, nitrogen, oxygen and argon are not infrared active (apart from very weak forbidden oxygen bands in the NIR). That leaves water vapour as the only gas that is more abundant than CO2 AND infrared active as well. As Michael Hammer has pointed out (I think), the important point is not that CO2 is “only” a few hundreds of parts-per-million in the atmosphere. It is that its emissivity (or absorptivity) is strong enough in the infrared for it to have an effect on the radiative properties of the atmosphere. Just how large that effect is remains, of course, the subject for debate here.
As often, I continue to follow these discussions with interest, though I have too little time for a complete reading of the posts and almost no time at all to comment. However, I must respond to Gordon. “That’s one of their more stupid claims since records of atmospheric density of CO2 was not kept prior to 1950.“ This is an outlandish claim. Is Gordon not aware that atmospheric CO2 levels prior to industrialisation (and the advent of modern direct measurement techniques) can be obtained from deep ice cores (which now extend back nearly one million years into the past)? And: “GISS has admitted they cannot account for 50% of ACO2 emissions”. This sounds to me like a statement of what used to called the “missing carbon problem”. (See Freeman Dyson’s illuminating, and spendidly written, account of this problem in his From Eros to Gaia.) It is known fairly accurately (20% is good accuracy in this kind of work, as Dyson notes) what the carbon emissions are. After doing the inventory, it was found that atmospheric CO2 was only increasing at about half the rate expected from the known CO2 going up. This came to be called the problem of the “missing carbon”. However, this is a much better characterised situation now, and I womder if Gordon’s statement is out of date. Any chance of a reference to the 50% number, Gordon?
Some really good posts in the last few hours. The best indication is that I am having trouble, reading the posts in isolation, in determining who is pro AGW and who anti. So we are rally starting to debate the science.
To try and reply in no particular order.
Gordon; I am sorry but I have to disagree with some of your comments. It is not valid to argue that CO2 is too dilute to have the claimed impact. The amount necessary depends on how active it is. Heinz Hug has measured the absorbance at 2000 abs and this is huge. Let me give you some analogies. If you take one tiny crystal of potassium permanganate (condies crystals) and put it in a bathtub of water the concentration is probably at most a few milligrams in 50 kg of water so about 1 ppm yet even at this concentration you can see a purplish cast to the water. It’s purplish because the patassium permangante is absorbing the yellow and green light. By contrast, you could put in far far more beetroot juice and see no noticeable colouration at all.
With regard to G&T I am probably going to get castigated for saying this; I did attempt to read the paper but I was not able to understand what he was getting at. I have seen a great deal of material suggesting that the atmosphere cannot radiate back to the surface because it is colder than the surface and according to the second law of thermodynamics a cold body cannot radiate energy to a warmer one. This is an incorrect argument. All bodies above absolute zero and with an emissivity above 0 radiate energy in all directions including to warmer bodies. How would they know which bodies were warmer and which cooler? The second law does not outlaw this. What the second law states is that the NET heat flow is always from warmer to colder. All that means is that the surface radiates more energy to the atmopshere than the atmosphere radiates back to the surface. I know this seems confusing and believe me I am also skeptical of the AGW hypothesis but I am absolutely certain of this piece of science. If you want, I can give you simple examples where that thinking will tie you up in knots.
Maybe there is something in G&T that I am not getting, if you know of any simple references please let me know.
Having said all that, just because I accept that CO2 does trap heat does not mean that I accept the AGW hypothesis of dangerous warming from increasing CO2. What is very much at issue is the degree of warming. My analyses suggest that while there is some effect is is very small and masked by other far larger effects. No where near the dangerous levels being touted by Hansen, Gore, the media and green activists.
I tend to accept the Mauna Loa data on CO2 but this does not mean the rise is due to man. I have an open mind on this. I know there is some isotope data to suggest it is but there is also much data going the other way and several factors that do not tie up for me. Maybe something to go into more detail about later.
Really most of the issue hinges on feedbacks and from my latest analysis specifically cloud feedback. There I very strongly disagree with the AGW hypothesis. My calculation suggest that clouds provide very strong negative feedback not positive as claimed by AGW models. Indeed, in my second article I talked about the paradox of Mackay versus Alice Springs. I strongly suspect negative feedback from clouds has a significant role in explaining this (yes Nick I do realise that latent heat effects are also very significant).
Now, on to the comments by SJT sod and Nick. All three of you are misunderstanding my point. As a cmplete climate model, what I generated is clearly not very good because it does not match reality. However my ntention was not to model climate but rather to model the claimed impact of CO2 and positive feedback from water on temperature. The model is simple because it only models one aspect. The point, as SJT has already noted, is that since the model output does not well match reality there must be other factors and their impact must be very large. This implies that CO2 is not the villian it is portrayed to be.
Further, the model suggests the projections being bandied about (yes Nick I will look up my references for the numbers I quoted, please give me some time) are not possible. This is a very serious issue.
Lastly, from what I have read, the current models do not allow for cosmic rays, they also assume cloud feedback is positive to give just 2 examples. The model is only as good as its input data and these are issues I very seriously question. I am sure there are other similar factors som known and ignored but others not even known. If you have lots of adjustable parameters you can tune a model to mach almost any known output especially when the output is a relatively simple curve. The problem is that you might be inflatng or supressing one parameter as compensation for a missing effect. The compensation works over a known data set but may fail spectacularly with unknown data. Thus the test for a model is whether it matches outputs not known at the time the model was tuned. This is really the only valid test of a model and as I tried to point out in my previous article, the models ave failed to match even short or medium term predictions. To say this is because of unforseable factors simply confirms what I have just said – a truely comprehensive and thus relaible model cannot have any unforseen factors. The claims of dangerous AGW are largely basd on model outputs and I consider the thesis very much not proven.
What I do know is that the temperature rise over the 20th century was;
moderate and indeed unremarkable in the historical context
poorly correlated with CO2 levels
appears to be reversing over the last few years
quite well correlated with solar activity
My simple model does not support CO2 causing massive warming from here on. I do not conisder all this cause for alarm or requiring urgent action.
Nick, you are right one can treat the model as a differential equation and yes as you get very close to runaway the time constant extends, in fact at thermal runaway it becomes infinite. For most people thats a more complex way of looking at the issue. However I doubt that one can justify a claim that water vapour feedback is close to thermal runaway. If the IPCC models incorporate that level of positive feedback it would explain their outputs.
Sorry for the long rambling post and even so there is a lot I have not discussed but long enough for now.
michael hammer,
I will not argue the merit of your simulation, out of my league.
But I have to disagree with you re. the quantity of CO2 and the effect thereof.
To retain heat or induce other parts of the atmosphere like W-vapor you do need a certain mass.
Not the same as colouring a liquid at all. Your example is a poor one, it describes a chemical reaction.
Even the believers are shying away from the claim that CO2 is the main culprit. If one reads the literature and blogs relating to CC, in as short a time as one year the emphasis has shifted markedly. One has only to look it up or have a good memory.
Sorry.
Marcus,
This is nonsense on at least two counts. There is no relevant chemical reaction in dissolving permanganate in water; many dyes have a similar effect. It takes only a tiny amount to make the solution absorb a lot of light. And the whole mass of the atmosphere is available to retain the heat absorbed by CO2 – it is very rapidly transferred to other molecules by collision.
And CO2 is still the main longlife GHG.
“And the whole mass of the atmosphere is available to retain the heat absorbed by CO2”
So, If I get this right, what you are saying is, that the tiny amount of CO2 keeps absorbing heat, transferring it to the atmosphere, cooling in the process, reabsorbing more heat and transferring to the atm. again and again is this so?
And I still put it to you that to do that, it needs a lot more mass, than a dye colouring a substance.
Even if I accept what you say, what is the other 99.97% of the atmosphere doing in the meantime?
Waiting to be heated by the minuscule amount of CO2?
BTW the example re. colouring the water is still a poor one, it just so happens that permanganate is a powerful dye while beetroot juice is not!
Marcus,
Yes, indeed, that is what local thermodynamic equilibrium means. All molecules are at the same temperature, and any deviation from that is very rapidly smoothed out (nanoseconds) by collisional exchange.
Molecules basically absorb quantitatively as if they were small spheres. A given mass absorbs about the same amount of light, whether distributed concentrated or dilute. If you could condense the CO2 in the air to a liquid or solid, it would form a layer about 3mm thick. Plenty of materials are quite opaque to light at that thickness.
OK Nick,
I still have enough time left to see this out, unless of course the timescale will be revised again.
All I can say, what others already did, “what we see is not what the models predicted”.
The less than 1C change in temperature over a century is not something I worry about, given that we are coming out of a cool period.
The graphs look very impressive too, until one realises the scale of change they represent!
But you heard this all before.
Time will tell.
Cheers
Marcus; what on earth gave you the idea that I think CO2 is the main culprit. Culprit of what precisely? So far all I have seen is a small temperature increase of at most 0.5C over 100 years if the record is not exaggerated by ignoring urban heat island. Even over that time the records i have seen show a temperature increase, then a decrease, then another increase and now another decrease all the time while CO2 is rising monotonically. That is not good correlation, its terrible correlation and all the future proclaimed temperature increase is conjecture and theory. What do you think I am trying to show in the article starting this thread.
However not believing in AGW does not mean I have to deny science facts that I know beyond any shadow of doubt. The comparison with dyes in water is appropriate. Permanganate in water does not absorb by virtue of a chemical reaction, the dye molecules are absorbing photons in exactly the same way as CO2 does just at a different wavelength.
In the 1950’s there was a revolution in the measurement of trace elements a revolution called atomic absorption spectroscopy. It works by shining a light of a very specific wavelength through a sample of gas and seeing how much is absorbed. The wavelength is chosen to match the absorption wavelength of the element of interest. We are able to measure concentrations down to 0.01 parts per million for some elements over a path length of 50 mm not 20 km. I know, I designed some of the instruments. More than $200 million of this equipment is sold annually world wide although it is now being superceeded by even more sensitive equipment. And by the way, this is measuring atoms not molecules and atoms are far smaller.
I can see the absorption of atmospheric carbon dioxide in an infra red spectrometer with the greatest of ease. Indeed one needs to purge such instruments with pure nitrogen to avoid unacceptable energy loss.
I am genuinely sorry if I appear to be embarassing or criticising you. Neither is my intention but I believe scientific accuracy to be vitally important in this debate.
Table 8.2, AR4, p631 has an average ECS for all relevant models of 3.2C; the CO2 component is 1.2C of this with water providing the remainder; this is of course where the whole house of cards falls down; water is not only not a uniform +ve feedback, but in increased lower cloud form and reduced upper cloud form neutralises any scintilla of warming left from the current level of CO2, which, according to log decline, must have all but exhausted its heating capacity at ~ 100ppm. Nick, you can take your pick with this; M’s theory or Steve Short’s version.
All that AGW has left is this ECS nonsense with lags and delayed responses and pipelines; all of which, apart from a dearth of empirical evidence, are completly negated by the contrary lag relationship of CO2 to temp; that is CO2 follows temp movement; but even this problematic correlation is illusionary as fig 5 here shows;
http://icecap.us/images/uploads/CO2,Temperaturesandiceages-f.pdf
I see that Nick has raised the old stallion of the LTE but neglects to say that an LTE or internally thermally consistent parcel of air will not exchange heat or energy with the surrounding air until the internal equilibrium achieves parity with the surrounding air; which is achieved by convection; in this fashion it doesn’t matter whether you can condense all the CO2 into a layer 3mm thick [I always thought you were superman Nick] the CO2 will still only absorb and transmit according to the OD; and that hasn’t changed [M theory], or if it has it doesn’t matter [Steve theory].
“All that AGW has left is this ECS nonsense with lags and delayed responses and pipelines; all of which, apart from a dearth of empirical evidence, are completly negated by the contrary lag relationship of CO2 to temp; that is CO2 follows temp movement; but even this problematic correlation is illusionary as fig 5 here shows;”
CO2 is usually a positive feedback, in this case it is a forcing. You are looking at the history, be we have not been present for most of that history doubling the CO2 content.
“the CO2 component is 1.2C of this with water providing the remainder; this is of course where the whole house of cards falls down; water is not only not a uniform +ve feedback,”
No one ever claimed it was. That is why the modelers are hard at work getting ready for the new generation of super computers to give them the ability to model the clouds in a realistic manner. Up to now the grid sizes were too big, now they are going to be on a much smaller scale.
Michael:
I haven’t had time to do this piece justice, being much too busy, but I note that commenters have shied away from discussing the merits of a simple model and principal components.
The subject of the worth of a simple model reminds me of the experience from a lifetime in the nuclear industry. Way back when computers were basic and you waited all day for a bit of macchine time, we had 0-dimensional models that just contained the basic physics and conservation equations. As time went by, research was done, computers got more powerful and the models beacme more sophisticated, going to 1-d and then 3-d with finer meshes and more detailed physical models. And guess what? The original models had got the basic behaviour right; all that time had done had given us more detail and allowed us to validate the models against all that good experimental data. So I agree with you that if your simple model contains what is believed to be the principal component and it doesn’t agree with the data (assuming the data is good!), then the principal component isn’t principal and something other component is driving the changes.
It seems to me that the climate has changed from warm to cold by several degrees (it doesn’t matter how many) several times during the current Holocene and thus there is some principal component (or two) that isn’t CO2 that has to be modelled besides the unproven component of CO2. There are two many unknowns (oceans, cosmic rays etc etc) for us to be able to say what the principal components are, but your simple model sure as hell shows it isn’t that harmless and vital constituent of the atmosphere, CO2.
Follow on for SJT “No one ever claimed it was. That is why the modelers are hard at work getting ready for the new generation of super computers to give them the ability to model the clouds in a realistic manner. Up to now the grid sizes were too big, now they are going to be on a much smaller scale.”
That has always been the excuse. The computers aren’t good enough.
Phillip, you put it very succinctly and more precisely than I have been. My experience with models is extremely similar to yours and a simple model should not be ignored or discarded just because it is simple.
Thanks for your input
“That has always been the excuse. The computers aren’t good enough.”
you are as bad as cohenite. If there is an area of science that is not understood well, it means the scientists are confused. If they are trying to get computers powerful enough to model the small grids needed to provide a more realistic simulation of clouds, it’s really just an excuse for their incompetence. Before Hubble, the things we didn’t know about the universe weren’t because the telescopes got too much interference from the atmosphere, it was because the astronomers were incompetent.
“And guess what? The original models had got the basic behaviour right; all that time had done had given us more detail and allowed us to validate the models against all that good experimental data. So I agree with you that if your simple model contains what is believed to be the principal component and it doesn’t agree with the data (assuming the data is good!), then the principal component isn’t principal and something other component is driving the changes.”
Logical fallacy of hasty generalisation. The climate and it’s response to warming is far more complex than what you were modelling. Have you read the IPCC reports?
SJT: Not sure I understand your post at 9:07am. Are you saying the climate scientists are confused and incompetent and therefore need powerful computers? Sounds like just an excuse to get more research funding and put off getting results that might eventually agree with the data, if and when they start using physical models and not arbitrary assumptions.
SJT at 9:21am. I notice you don’t answer the point about principal components – just claim logical fallacy without any explanation.
I agree the climate is complex and we don’t understand the half of it. I agree the open climate system is more complex than my closed system. That is one of the reasons why I don’t believe all these projections – plus the fact that there is no quality control and no validation of the models.
Yes, I’ve read sufficient of the IPCC reports to know bullshit when I see it. The SPMs are full of it and not a lot of science.
In re: the issue of different time constants, here is a list from Lubos of the different timescales that different climate processes act on. I think that the sections on different ocean processes are particularily relevant.
http://motls.blogspot.com/2009/01/weather-and-climate-noise-and.html
Cheers, 🙂
“SJT: Not sure I understand your post at 9:07am. Are you saying the climate scientists are confused and incompetent and therefore need powerful computers? Sounds like just an excuse to get more research funding and put off getting results that might eventually agree with the data, if and when they start using physical models and not arbitrary assumptions.”
I really am surprised at the lack of professional courtesy. Did you make the same accusations of greed and incompetence of your fellow workers when they were developing their models, and seeking to make sure they had their models right?
SJT: You still haven’t explained what you meant in your post.
As for courtesy, well you are the one who introduced the subject of incompetence, which you haven’t explained in a way I can understand. I have accused no-one of incompetence.
As for my fellow workers, all I can say is that everything they did was totally open, was based on the best scientific evidence and was fully archived for all to see. It was not based on arbitrary assumptions, hidden methods, non-archiving of data and methods and hiding behind use of FOI laws.
“As for courtesy, well you are the one who introduced the subject of incompetence, which you haven’t explained in a way I can understand. I have accused no-one of incompetence.”
You accused them of blaming the computers, implying they were to blame.
Their work is open, the only problem is people like McIntyre seek to discredit them, and they see no point on helping someone who’s trade is character assassination. You only have to read the comments on his web site, including those by McIntyre himself, to realise what is about. Not one topic is raised about research by Climate researchers who disagree with him that he doesn’t make some snide comment implying incompetence or dishonesty. He then expects co-operation and assistance, that takes up their valuable time, not in the interests science, but in helping him stab them in the back.
He knows how science works. You don’t have to provide every detail of every piece of information that goes into your papers. The scientific process to date has depended on people getting up, doing their research, and saying what they think. If he thinks he can do better, let him go out and do his own research, and publish his own papers. His ‘audit’ scam is a good one, it puts no onus on him at all, and it curiously ignores the ‘papers’ from people like G&T or Miskolczi.
SJT I have to say I have very considerable problems with your 4:47 posting on many fronts. You comment that McIntyre criticises the work of people trying to do serious research and includes snide comments. I work full time as a senior research scientist/engineer. I am spending a very considerable portion of my free time in trying to do serious research on climate change and I am publishing my work in a public domain. You and others see fit to criticise my work and a significant percentage of the comments include snide remarks implying incompetence or bias.
I accept and expect this to happen. If I didn’t I would not be posting. My point is that you and others are doing exactly the same as what McIntyre is doing. It is hypocritical to complain that such actions are unfair yet do them yourselves.
Criticism of published scientific work (no matter what the forum) is fair and reasonable whether you or McIntyre are the ones doing it. It is in fact a necessary test of new theories. Withholding of informaton to prevent or frustrate such a process is not fair and reasonable. It suggests very strongly that the researcher either has something to hide or has insufficient confidence in his work to allow such scrutiny. I have tried to make full disclosure in my posts and am very swiftly and soundly brought to task if someone thinks I have omitted an item. Thats the price scientists need to pay for publishing. McIntyre is not trying to stab scientists in the back. He is trying to find an error in their work. If he can, his actions were justified. If he can’t, the fact that he can’t increases the status of the theory being postulated.
In this case however the situation is very much more serious. This is because the scientists are not just putting up theories with the aim of increasing knowledge and understanding. I very much doubt that McIntyre and others would bother auditing it if that were the case. Many of the same scientists are also demanding long and loud that society makes massive changes based on those theories. The thrust of you post suggests to me that they are saying you must take our word for what we say, you do not have the right to check our work, just accept it and pay out trillions of dollars on our say so. To me that is truly monumental arrogance.
If you are demanding action at that sort of level it makes the onus of complete disclosure far far greater. It also means that the rest of society has not just the right but rather the duty to subject the theory the most intense scrutiny. And the theory would have to stand up to such scrutiny essentially without any flaw.
Yet, when McIntyre did this in the case for example of the hockey stick what he showed were serious flaws. If an audit team looking at an aircraft design found such flaws in one set of calculations I am sure they would go through the rest in the most minute of detail. Indeed if they did not they could be charged with negligence. The tax office do take an exactly similar approach if they find such a flaw in someones tax return. Any objection to such scrutiny I am equally confident would be taken as tandamount to an admission of something to hide making the investigation even more significant. Yet what is being demanded of society with respect to AGW is orders of magnitude more significant than either of my examples.
You comment he does not audit papers such as G&T or Miskolczi. Maybe not but they are not calling for society to spend trillions of dollars based on an unproven theory. It is not about being fair to both sides. It is about testing whether or not massive change to our society is really necessary (in my book it is massive damage but I am sure you would dispute that with me).
His audits are not a scam, they represent a great deal of hard and controversial work. To say there is no onus on him is ridiculous. If for example, the hockey stick had been proven correct and McIntyre wrong, McIntyre’s reputation would have been significantly damaged.
I think I have treated you with respect. You come here, make your claims, and respond with courtesy to people like Nick Stokes. I think you are wrong, I think you really need to know what they case for AGW is before you start being to critical of it, but that’s about as far as it goes.
“You comment he does not audit papers such as G&T or Miskolczi. Maybe not but they are not calling for society to spend trillions of dollars based on an unproven theory. It is not about being fair to both sides. It is about testing whether or not massive change to our society is really necessary (in my book it is massive damage but I am sure you would dispute that with me).”
G&T and Miskolczi are being used to stop action being taken to prevent AGW, which, according to the scenarios, is going to be far more costly than billions of dollars. Sites like this publish and promote them, when they are patently wrong. People believe them and take comfort in them. If there is a case against AGW, it should be able to stand on it’s own, without recourse to such endevours.
I treat McIntyre with the respect he deserves, which is very little. The scientific papers are written in a professional manner, he attacks the authors personally, and encourages comments that do so as well.
sjt,
I am a supporter of AGW theory and I must say, your posts are completely embarrassing to me. We essentially agree with the challenges facing the world from anthropogenic CO2 emissions, however your lack of good manners and total disrespect for opposing views is appalling.
If skeptics make claims based on theory and well intentioned observation, it is the duty of scientists to respect their arguments and to refute them through reasoned logic, not rude ad hom responses.
If you don’t like the arguments put forward on this blog, either use good science to refute them or go away. No-one wants to read insults, we just want good debate.
I suggest that along with your extensive reading on climate issure, you also take some time to study up on good manners. It will earn you far more respect than silly name-calling.
McIntyre says that Bob Tisdale has an excellent analysis of SST.
What does that analysis include?
“Hmmm. It looks as though, if you’re a SST data producer, downward biases are bad, but increases in trend with each update are good.”
Accusations of bias or fraud.
“We’re all familiar with cherrypicking bias in Team multiproxy studies e.g. the addiction to bristlecones and Yamal.”
Ditto.
“The above relationship is “significant” in statistical terms. But why should there be a relationship between the mean stratified by model and the standard deviation stratified by model. I’ve had to scratch my head a little to even think up how this might happen. I think that such a relationship could be established by a bias in favor of inclusion of (shall we say) DD trends relative to their less endowed cousins.
Or perhaps there’s some mundane reason that would trouble no one. Unfortunately, IPCC doesn;t seem to have established objective criteria requiring modeling agencies to archive all their results and so, for now, I’m left a bit puzzled. For the record, I’m not alleging such a bias on the present record. But equally it is entirely legitimate to ask what the selection criteria are. Not that I expect to get an answer.”
He’s not making any accusations, but he is. He can’t have it both ways.
I have only one thing to say about SJT and it agrees with abt. SJT is an embarassment and a complete waste of time on this blog. He comes up with nothing of any worth and is totally blinkered in his views. He has not answered any of my questions, just side-stepped the issue by accusing others.
“sjt,
I am a supporter of AGW theory and I must say, your posts are completely embarrassing to me. We essentially agree with the challenges facing the world from anthropogenic CO2 emissions, however your lack of good manners and total disrespect for opposing views is appalling.
If skeptics make claims based on theory and well intentioned observation, it is the duty of scientists to respect their arguments and to refute them through reasoned logic, not rude ad hom responses.”
You must be new? I have been abused relentlessly here, for putting up arguments the best I could. You get sick of it after a while, and just go with the flow. I’m happy to hold a civil discussion with anyone here, but it cuts both ways.
Mike Hammer sticks to the point, he doesn’t make personal attacks, I believe I have responded in kind.
Hello SJT; after reading your reply I went back and re-read what I had written. I admit that my last sentence first paragraph is poorly phrased and can be miinterpreted. What I meant was that a reasonable number of all the comments in reply to my post include snide remarks NOT that a reasonable number of your comments do. I apologise for my poor phrasing.
With regard to the rest of your post, I have read a considerable amount of the pro AGW and I believe I do have a reasonable handle on what he case is. I recognise that green house gases do trap heat, I have documented that in my posts. I have acknowledged Nick in some of my replies because while he is critical (which is fine by me) he takes the time to look in detail at what I have written and tries to identify errors. The discusssion over model inital conditions, start time and equivalent ways of looking at the model are cases in point. He is also prepared to admit occasionally when he agrees with what I claim. He has also done this with regard to my previous postings. A critic who does not agree with you but is objective and rational is the most valuable critic of all.
Some of the things that really worry me. You state that CO2 is normally a positive feedback. IPCC claim water vapour is a positive feedback term. The models treat clouds as a positive feedback term. Everything seems to be positive feedback yet all natural systems I can think of have net negative feedback. The fact that climate has been stable enough for life to continue for billions of years very strongly suggests negative feedback. Claiming so many factors are all positive feedback seems to me to require very substantial justification which I don’t see.
On ICECAP.US today there was an article which cited a graph of global temperature from satellite data since 1979. I suspect you will feel Icecap is a skeptical site and therefore untrustworthy but the graph is there and Igot the impression is it simply reporting raw satellite data. This data shows zero discernable trend in the last 30 years. It went up a bit in the 1990’s and down since 2002 otherwsie flat with wriggles. Is this the record which justifies such extreme claims? Is the data fake? If so point me to real satellite data (not ground station data).
I have personally looked at Hansen’s site a number of times over the years and I have seen how the historical record is repeadly re-written, always to depress temperatures before 1950 and increase them after 1950. Why does a historical record require so many revisions (I guess you will say because new corrections come to light but I do not accept that explanation) and why is every correction in the direction of making AGW look more alarming? Why has Hansen recently dropped all correction for urban heat island yet insists on adding pro AGW corrections for weather stations moving from cities to airports on the basis that airports are cooler? Ther are cooler becuase of urban heat island. To me this is absolute evidence of bias and distortion and my response is to reject all his claims.
Then again the AGW advocates after the 2007 summer claimed that the arctic summer ice would disappear completley within a very few years. Yet this year it seems to have recovered to near the long term average. The there was the claim that the new ice was much thinner and more vulnerable yet a recent survey condcted from a DC3 towing a sensor array found the ice was twice as think as previously thought (4 metres not 2 metres).
Hansen claims sea level rises of several feet, Gore claims 30 feet yet the actual sealevel rise over the 20th century is a few cm and even that appears to have stopped over the last few years.
Wherever I look I find alarmist AGW claims which the experimental data contradicts. All the alarming scenarios are future projections, I see no evidence of them in the current experimental data. I have seen this sort of scenario before and it always ended up withe alarmism proving to be a non event. This time the stakes are very high indeed. That is what started me thinking about AGW and started me on the path of my own investigations. Investigations which are leading to these posts.
I must also say that I also disagree with some of the skeptical claims and I think I have made that clear in my comments from time to time. While I state that I am very skeptical of the dangerous AGW theory I follow the science and if some compelling reliable scientific evidence came to light that confirmed AGW I would change my mind. I have not seen such evidence (and I have looked), to the contrary, I am seeing more and more evidence all the time opposing AGW.
I have a question to all AGW proponents reading this site. Is there any hypothetical evidence which would make you change your mind? Think about this carefully because if the answer is no you are not a scientist or following the science you are believer and AGW has become a religion to you.
“Some of the things that really worry me. You state that CO2 is normally a positive feedback. IPCC claim water vapour is a positive feedback term. The models treat clouds as a positive feedback term. Everything seems to be positive feedback yet all natural systems I can think of have net negative feedback. The fact that climate has been stable enough for life to continue for billions of years very strongly suggests negative feedback. Claiming so many factors are all positive feedback seems to me to require very substantial justification which I don’t see.”
Life can adapt to the most murderous conditions, given enough time, and by making compromises via adaptation. There are bacteria living on volcanic vents, and underground, kept alive by the natural background radiation. Life goes on, but there are also cases of mass extinctions. These have happened for various reasons, but one reason is climate change.
The climate itself is highly unstable, if you look at it in a geological timeframe. There are quite evident swings between ice ages and warm periods.
It is also bounded, so that there are limits to how hot or cold it can get.
I also appreciate your dialog with Nick Stokes. As I said, it was very informative. I have said many times here, the only real debate is how much warming there will be due to AGW, and it good to learn from such a debate in progress.
“I have a question to all AGW proponents reading this site. Is there any hypothetical evidence which would make you change your mind? Think about this carefully because if the answer is no you are not a scientist or following the science you are believer and AGW has become a religion to you.”
I would first ask you, as you do accept the basic science. Do you think it is possible that the laws of physics will suddenly change, and greenhouse gases will lose their properties to absorb radiation, or that all along scientists were wrong in their theory about how greenhouse gases work? I am not talking about the magnitude, but just the fact that there are greenhouse gases, and without them, the earth would be much cooler, and probably in an ice age.
SJT no the laws of physics will not suddenly change in a way relevant to the AGW debate. No, green house gases will not suddenly change their radiative properties and I am not aware that anyone has even vaguely suggeted such a thing. That is not what this debate is about.
Are scientists wrong in their theory about how green house gases work? Depends on which scientists. Yes I think some are possibly wrong. That was the entire basis of my first article pointing out where I though Kiehl and Trenberth were in error. I suspect what you intended by the question was “are scientists wrong in their belief that green house gases absorb thermal infrared energy”. If thats what you intended then I agree that GHG do absorb thermal infra red but I do not agree with the progressive emission from the bulk of the atmosphere which is a significant feature of many models. I do not agree with the concept of an equivalent radiation altitude.
Am I splitting hairs here? No I don’t think I am, to me this is a fundamental error in AGW theory and I have documented in detail with supporting calculations why I think so.
Could people like Misolczi and C&T be correct? I have tried to understand their theory but have been unsuccessful. This might be becuase they haven’t explained it well enough but it might also be because of my pre-conceptions or my limited abilities. I can’t comment on something I don’t understand. Maybe if I do understand it will be like a light turning on in my mind.
However to turn to some of your other points. When I talk about climate being stable for billions of years and you claim it is not we are talking at cross purposes. Yes I agree the global temperature swings up and down continuously in a largely unpredictable way but these swings are at most a few degrees. The largest claim i have seen is around 6C. That is what I mean by stable. It could swing down to -10C average and up to +60C or +80C for example yet it has not done so.
You comment that it is bounded, so there are limits to how hot or cold it can get. An interesting claim. What sets those limits? For example on the cold side why not swing down to the temperature without any green house effect -33C? On the hot side why not swing up to the temperatures of Venus? The only possible answer is that there are negative feedbacks in play and pretty strong negative feedbacks. Thus the claim becomes that for small changes the feedback is positive yet for large changes strong and overriding negative feedbacks kick in. That is a rather bizarre position. What are the mechanisms of these negative feedbacks? Why do they not act for small changes? What sets the point where the negative feedbacks outweigh the positive feedbacks? Such questions are absolutely fundamental to the proving the AGW hypothesis. Remember when people like Hansen talk about tipping points they essentially denying the existance of negative feedbacks and claiming the positive feedback goes above 1 (thats what a tipping point means). If we don’t understand the negative feedbacks how do we allow for them in the models? How do we know they don’t work for small changes in inputs? If they are not there then what does your statement that themperature is bounded mean?
Consider an interesting scenario. The oxygen on earth. This is formed by life, oxygen is a very highly reactive gas and would not remain otherwise. Before life started the oxygen in our atmosphere would have been carbon dioxide. Now go back a bit further as earth was cooling. Before it cooled all the water in our oceans would have been water vapour in the atmosphere. Worse, a huge amount of carbon dioxide is tied up is carbonate rocks. But carbonate rocks form from water and decompose at high temperatures (thats why cement productions releases CO2) thus as earth was cooling there would have been no carbonate rocks and even more CO2 in the atmosphere. We are talking aout 1000’s of times the current concentration of CO2 and water vapour. Despite all this the earth continued to cool, water vapour fell as rain and the temperature dropped low enough for life to form. No runaway warming even at such extreme GHG levels.
No I have heard the counter claim that the sun was cooler at that time (25% was the number I read) but that wont work because the time constants are extremely different. The sun would have warmed up very slowly. By contrast, once life formed it proliferates very quickly. Thus if the changing solar constant were the answer as soon as life formed the CO2 content would have dropped and the earth would have frozen solid extinguishing life again. The creation of life is a massive state change to the system not just a feedback term. Remeber also if the 25% figure is what is being claimed that amounts to 86 watts/sqM. Compare that with the claimed 3.7 watts/sqM from CO2 doubling!!!
We are indeed arguing about the magnitude of any GHG effects but that is the crux of the problem. 3C as I have heard bandied about repeatedly would be significant. If, as I suspect, it is more like 0.3C it is of little relevance and certainly is not a reason to massively disrupt our society. The magnitude of an effect really does matter. Infact it is paramount.
Michael: I have a question to all AGW proponents reading this site. Is there any hypothetical evidence which would make you change your mind?
OK, I’ll come in on that one. I found AGW theory convincing thirty years ago, when there was essentially no supporting temperature data, melting Arctic ice etc. And I still do. The crucial argument is the earth’s radiative balance. It’s upfront in the AR4 SPM (Fig 2) – about 2 W/m2 extra incoming heat since industrialisation. Too little to notice year by year, but it goes on and on. The argument is not primarily based on temperature graphs or last year’s Arctic ice.
Now we’ll soon have direct confirmation of that from two sources. One is better satellite measurements of outgoing IR, which will actually discriminate that imbalance. That will be crucial. The other, more indirectly, is from the ocean, particularly the Argo studies. This is an exceedingly ambitious undertaking, and it will take years before a total planet heat balance can be reliably evaluated from within. But that will come one day.
Either of these developments could destroy the AGW argument. But the evidence to date is strongly the other way.
“SJT no the laws of physics will not suddenly change in a way relevant to the AGW debate. No, green house gases will not suddenly change their radiative properties and I am not aware that anyone has even vaguely suggeted such a thing. That is not what this debate is about.”
What I was getting at, are there facts that aren’t going to change. These physical properties won’t be disproven, ever, IMHO. They are based on the laws of physics, hence there won’t ever be evidence to disprove them.
“Are scientists wrong in their theory about how green house gases work? Depends on which scientists. Yes I think some are possibly wrong. That was the entire basis of my first article pointing out where I though Kiehl and Trenberth were in error. I suspect what you intended by the question was “are scientists wrong in their belief that green house gases absorb thermal infrared energy”. If thats what you intended then I agree that GHG do absorb thermal infra red but I do not agree with the progressive emission from the bulk of the atmosphere which is a significant feature of many models. I do not agree with the concept of an equivalent radiation altitude.
Am I splitting hairs here? No I don’t think I am, to me this is a fundamental error in AGW theory and I have documented in detail with supporting calculations why I think so.”
The debate between you and Nick was never resolved. From what I could tell, each point you raised was answered by him.
AGW theory that the earth will most likely reach 3C higher is of course something that can be proven wrong. So far, though, I think the evidence indicates it is correct.
Nick your comments. Certainly if the earth is warming there must be an energy imbalance otherwise where would the energy be coming from. However this says nothing about the source of the imbalance. Just showing an imbalance does not prove in any ay that rising CO2 is the cause. It also does not show that the imbalance will continue in the same direction in the future. Look for example at the website given below
http://www.sciencemag.org/cgi/content/abstract/304/5675/1299
it looks at earth’s albedo and claims a steady decrease from 1984 to 2000 with a strong decrease between 1995 and 2000. Then after 2001 a complete reversal with albedo rising again. Falling albdeo causes more incoming solar energy to be captured leading to a warming energy imbalance. I have seen other similar claims elsewhere as well. The data matches the claimed warming trend pretty well – temperatures rising till about 2000 and then falling therafter. This data it seems to me supports Svensmarks theory pretty strongly. Changing solar magnetic field modulating cosmic rays and thus cloud seeding. Much better match than claiming rising CO2 as the cause. I do not accept that outgoing IR will necessary dominate the imbalance, i suspect albedo changes might be much more significant.
I accept there has been some warming over the 20th century. I think the amount is exaggerated by people such as Hansen but non the less some warming has occured. I can also accept that a portion of this warming has been due to CO2 increase. I contend that the contribution from CO2 is far less than claimed by AGW activists and question whether CO2 is the dominant driver. I contend that the correlation between temperature and CO2 level is very poor, reinforcing my view. I also question whether the temperature rise will continue into the future. Indeed there seems to be evidence emerging that the sign of the temperature change has already reversed in the last few years (eg: the satellite data).
The AGW alarmists seem to be stating that clearly CO2 retains heat so increasing the level must retain more heat warming the planet so the AGW hypothesis must be right. Yes rising CO2 probably does retain more heat and cause some warming but the error lies in the claimed magnitude of the effect not as to whether it is right in principle.
After all, I can claim that lighting a match in a room must warm the room and I am indisputably correct in an absolute sense but the magnitude of the effect is so close to zero that for practical purposes I might as well be wrong.
SJT, I don’t know what you are getting at with your 10:38 post. The laws of physics are not under dispute. It is not a law of physics that clouds provide positive or negative feedback. It is an experimental observation that CO2 blocks thermal infrared at 15 microns (and that is well proven and exceptionally unlikely to change) but the magnitude of the effect in a planetary atmosphere is not a law of physics. It is the application of the laws to the plantary situation that is the subject of the debate.
just submitted a long post but it has not appeared? Wonder if something is wrong with the system. I will try again and repeat at least the gist of it.
Nick, of course if the earth is warming an energy imbalance must exist. I dispute the amount of warming claimed by people such as Hasen but I acept that some warming has occured over the 20th century. However this does not give any indication at all as to the cause of that warming or energy imbalance. Have a look at the site below
http://www.sciencemag.org/cgi/content/abstract/304/5675/1299
This reasearch paper claims they have measured steadily falling albedo from 1984 to 2000 followed by a complete reversal (ie: rising albedo) from 2001. That would very much explain an energy imbalance and would also strongly support Svensmark theory. It also suggests the recent warming may be changing to cooling.
From my perspective, AGW alarmists take the line CO2 is a green house gas which retains energy hence increasing the CO2 level must retain more energy hence the AGW theory is proven. No, it is proven in principle but the erorr lies in the claimed magnitude of the effect. If that is greatly exaggerated then the claims are still wrong.
To give a simple example, I can claim that lighting a match in a room warms the room and technically I am correct. But the practical effect is immeasurably small so in a practical sense my claim has no merit or value.
SJT, I don’t know what you are getting at with your 10:38 post. The laws of physics are not under dispute. It is an experimental observation (and a very reliable one) that CO2 absorbs energy at 15 microns but that impact that has on retained energy in a planetry atmosphere is not a law of physics. It is not a law of physics as to whether clouds contribute positiveor negative feedback. These things are derived using physical laws but is the derivation correct? Also, are there other factors which have not been considered. That is what is under dispute.
“Consider an interesting scenario. The oxygen on earth. This is formed by life, oxygen is a very highly reactive gas and would not remain otherwise. Before life started the oxygen in our atmosphere would have been carbon dioxide. Now go back a bit further as earth was cooling. Before it cooled all the water in our oceans would have been water vapour in the atmosphere. Worse, a huge amount of carbon dioxide is tied up is carbonate rocks. But carbonate rocks form from water and decompose at high temperatures (thats why cement productions releases CO2) thus as earth was cooling there would have been no carbonate rocks and even more CO2 in the atmosphere. We are talking aout 1000’s of times the current concentration of CO2 and water vapour. Despite all this the earth continued to cool, water vapour fell as rain and the temperature dropped low enough for life to form. No runaway warming even at such extreme GHG levels.”
The projections of the IPCC are not for runaway, I have asked a scientist if it is possible, (he is actively involved in the research), and he thinks it extremely unlikely. The enhanced Greenhouse which involves positive feedback effects is not runaway, it will be limited by the strength of the sun and negative feedback effects. For example, there is only so much ice and snow that can melt, which limits the effect of albedo change.
Michael, your last two comments had gone to spam! sorry. now released.
“SJT, I don’t know what you are getting at with your 10:38 post. The laws of physics are not under dispute. It is not a law of physics that clouds provide positive or negative feedback. It is an experimental observation that CO2 blocks thermal infrared at 15 microns (and that is well proven and exceptionally unlikely to change) but the magnitude of the effect in a planetary atmosphere is not a law of physics. It is the application of the laws to the plantary situation that is the subject of the debate.”
I was just pointing out, there is a line between what we would reasonable expect to be disproved or not. CO2 is going to absorb and re-emit radiation at specified frequencies, I am not expecting that to ever be challenged. Does that make my belief in that religious? That doubling CO2 will cause a 3C rise I am quite ready to accept can be proven or rejected. However, parts of that 3C will have a rock solid physical basis.
Michael,
You asked what could make the difference. Well, improved satellite outgoing radiation measurements can discriminate. If it’s GHG, then there will be a reduction in LW. If it’s albedo reduction, there will be a reduction in SW.
But as I say, my belief is that the greenhouse effect is correctly calculated. That extra 2 W/m2 is there. Albedo may fluctuate, but the GE won’t go away.
No SJT, I cannot agree with what you write. I was not asking if there was anything that would make you question extremely well proven experimental observations and extremely well proven “laws of physics” (although even those can justifiably be questioned at times eg: Einstein vs Newton). I asked whether there was any data that would make you change your mind about a theory that I contend is far from proven.
You say part of that 3C will have a rock solid physical basis. The first reply is again a matter of degree. If say for argument it turned out that CO2 only caused 0.3C not 3C then the theory of a dangerous level of warming from rising CO2 would be disproven. The magnitude matters. Secondly look at a few what ifs. If it turns out that the long wavelength side of of the CO2 absorption peak is fully overlapped with water vapour then half of the line broadening ceases to have any impact and that contravenes no laws of physics. Very hypothetically (and I am not suggesting this could be fact) if it turned out that CO2 had some currently not known action which resulted in lowering temperature then rising CO2 might have a negative effect not a positive effect without breaking any known laws of physics (maybe an action through enhancing plant growth for example).
As I have pointed out repeatedly, The practical theory of AGW that we are debating and that is the justification for all the calls to remodel society is that rising CO2 will cause a dangerous degree of warming. It is not fair to say that this follows inherently from the laws of physics. I refer you to my example of lighting a match in a room and expecting warming. I am sorry to say it but your comment is exactly re-iterating the alarmist scenario I outlined in my earlier pst.
IMO, there are two basic approaches to disprove the enhanced greenhouse effect as currently constituted.
#1. Demonstrate that the forcing to date is greater than currently measured. If the forcing since 1950 was shown to be 5W/m2 instead of ~1.6W/m2 – the effect of additional ~2W/m2 to get to a concentration of CO2 of 560ppm would have to be less than predicted.
#2. Demonstrate that various feedbacks are less strong than anticipated.
Cheers, 🙂
“No SJT, I cannot agree with what you write. I was not asking if there was anything that would make you question extremely well proven experimental observations and extremely well proven “laws of physics” (although even those can justifiably be questioned at times eg: Einstein vs Newton). I asked whether there was any data that would make you change your mind about a theory that I contend is far from proven.”
I was just pointing out that you have beliefs that you would class as ‘religious’, too, if I take your statement literally.