Radiative equilibrium is one of the foundation stones of radiative forcing theory. But it is not a law of physics, only a rather archaic and untested supposition found in climatology textbooks alone.
“For the Earth to neither warm or cool, the incoming radiation must balance the outgoing.”
Not really.
It’s best to regard radiant energy simply as a finite power source — indeed, that power is expressed as watts per square meter. An object is said to “cool” by radiating, yet this would seem to imply that restricting its radiation will make it get hotter and hotter. That’s the very premise of greenhouse theory, of course, that by disturbing outgoing radiance any magnitude of temperature gain is possible. But this is easy to test.
Confine a lightbulb inside an infrared barrier (like a globular mirror) and electrically feed one watt to it. After a while, will it be generating the heat of a thousand watt bulb? No.
When its temperature is consistent with the input, further heating stops.
It’s like water seeking its own level. Lacking any means to radiate to its surroundings, the lightbulb merely gets as hot as a watt of power can make it, which is not much hotter than what it would be in the open. If not, we’d be able to generate incredible temperatures very cheaply. Just confine, wait, and release.
Conservation of energy: it’s not just a phrase. The theory of radiative equilibrium arose early in the 19th century, before the laws of thermodynamics were understood.
From The Analytical Theory of Heat:
The radiation of the sun in which the planet is incessantly plunged, penetrates the air, the earth, and the waters; its elements are divided, change direction in every way, and, penetrating the mass of the globe, would raise its temperature more and more, if the heat acquired were not exactly balanced by that which escapes in rays from all points of the surface and expands through the sky. — Joseph Fourier (1768-1830)
Alan Siddons
Holden, Massachusetts
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Er, isn’t Fourier correct? Power is energy transferred per unit time. If you continuously transfer energy to something, and it doesn’t lose it, it will gain and keep gaining energy. Alan says the enclosed lightbulb is not much hotter than the unenclosed lightbulb, but “not much” hotter is still nonetheless – hotter. And as Ender said in his reply, the extent to which heat increases will depend on the physical properties of the enclosure.
Jennifer
don’t you realise that publish such ignorant waffle as this demeans the integrity and repuation of your site and the organistion you represent?
Wow SJT,
That was an impressive counterpoint post!
How about the fantastic idea of presenting a counter argument against it?
We will still be arguing the increments [sweating the small stuff] in a 100 years time.
The facts are obvious.
There are no tipping points or we would not BE here.
Get used to it. Concentrate on the real problems.
As I said at BB’s blog, “good economies don’t guarantee good eco-ethics but crook ones almost certainly guarantee crook ones.”
Especially with 12 billion people.
Alan’s example could possibly be better as FIG 1 from Robitaille’s paper on Stewart’s Law shows;
http://arxiv.org/ftp/arxiv/papers/0805/0805.1625.pdf
But ender is most definitely not correct; look at Eli’s piece on LTE’s, in particular, anonymous’s comment at 7.33 pm where he defines a LTE in terms of the mean free path of atmospheric nitrogen or oxygen, the main components of the atmosphere;
http://rabett.blogspot.com/2007/03/what-is-local-thermodynamic-equilibrium.html
Amidst the numbers the point is that there are discrete gaseous parcels of air which have an effective internal thermal equilibrium; according to Stewart’s Law the GHG’s within that parcel of air will emit as much as they absorb; an infinitesimal increase due to an increase in CO2 content of the LTE parcel of air will not cause a layer opaqueness because, as Chilingar et al show, adiabatic convective exchange takes that air upwards; CO2 emission within the parcel of air, because it is a LTE, will be upwards as per the thermal gradient (which contradicts Philopona’s model predictions and conclusions); again this is an example of how heat transfer negates LTE heat and energy build-up. Alan’s example is not right because there is not an LTE in the atmosphere which is internally sourced with power (apart from his globe!) and seperated from the thermal and radiative equlibrising mechanisms in the atmosphere. In fact his light bulb proves his point sufficiently without a cover, just as ender’s engine at another post, disproves his.
“There are no tipping points or we would not BE here.”
In geological terms, we have only just turned up. In geological terms, there have been massive and rapid swings in climate, due to the so called ‘tipping points’, which have resulted in mass extinctions. We could be in the middle of triggering such a swing right now.
mitchell porter said..”If you continuously transfer energy to something, and it doesn’t lose it, it will gain and keep gaining energy”.
There’s more to it than that. For example, if you set up a simple electric circuit with a voltage source and one resistor in the circuit, electrical energy will be transfered to heat energy. The relationship is P = EI and Energy, e = EIt in watt-hours.
That energy is driven by a potential difference in the source. Heat operates in the same way, you need a difference in heat potential for heat to flow. So, if you transfer heat to something it will only transfer till a state of equilibrium is reached.
In this article: http://cfa-www.harvard.edu/~wsoon/ArmstrongGreenSoon08-Anatomy-d/Lindzen07-EnE-warm-lindz07.pdf
Lindzen states:
“…in current models, the natural greenhouse substances (water vapor and clouds) act in such a manner as to greatly amplify this warming. This is
referred to as positive feedback. There is something very seriously wrong with this oversimplified picture. Namely, the surface
of the earth does not cool primarily by thermal radiation”.
It’s pretty obvious that modelers have bitten off away more than they can chew. They are wrong, pure and simple. The IPCC is wrong by association.
“That energy is driven by a potential difference in the source. Heat operates in the same way, you need a difference in heat potential for heat to flow. So, if you transfer heat to something it will only transfer till a state of equilibrium is reached.”
Well put!
The subject is radiative equilibrium, so I presented a scenario in which the object is incapable of transferring any heat at all. In reality, if a watt goes in and a watt of heat can’t get “out,” the body stays at a temperature that a watt can deliver, nothing more. It can not gradually acquire a radiative strength of a billion watts — although science charlatans will tell you different. Heat transfer is a ‘meet its own level’ kind of thing; it’s not like pent-up rage leading to a primal scream. X input leads to Y temperature. If the object is already at Y temperature, X input has no effect. That is THERMAL equilibrium, a legitimate concept. But radiative equilibrium is a fiction.
Energy out must equal energy in, says this theory. Which does sound plausible on its face. In this view, however, if the light emitted by a heated object is suppressed in some way, its radiant energy output will exceed the input until it breaks through the barrier… in obedience to the law.
This notion originates from a long-ago misconception about how glass greenhouses work, thus the family name this “effect” goes by. It was believed that glass blocked the passage of “dark radiation” (infrared) and kept storing energetic photons inside it. Once those photons had accumulated enough power to overcome the barrier, radiative equilibrium was achieved. Ergo, sunlight enters, heat is generated and dark light is emitted. This dark light is amplified because of the blockage and finally exits at the same magnitude as the entering sunlight. But only after the light “trapped” inside has raised the greenhouse’s temperature. Since the barrier will keep raising the temperature until the barrier is broken, increasing the barrier’s strength will get you any amount of internal heat you want.
It is 19th century poppycock. And here’s a telltale sign of it: Why do you always see a “layer of greenhouse gases” depicted overhead in illustrations, when you KNOW that these molecules are at their densest concentration right at your feet? Because these illustrations are showing you the theory’s genetic lineage. That “layer of greenhouse gases” is merely a pane of ceiling glass in another guise.
“How about the fantastic idea of presenting a counter argument against it?”
How can you argue against someone telling me about the power of crystals? It’s just as ignorant.
It would be nice if people are going to argue about thermodynamics that they had at least a small understanding of thermodynamics. It would help if they had a small understanding of just what AGW theory claims. I think I have at least that, and the topic is nonsense, and embarassingly so.
It claims there is no such thing as a radiative equilibrium, for example, then goes on to directly describe one.
The ‘leaky bucket’ is just as good a description of the greenhouse effect. Imagine pouring water into a bucket at a fixed rate. It leaks, so the water pours out the bottom. Depending on the rate at which the water pours in, and the rate at which it leaks out, there will be a set water level in the bucket. Change the rate at which it enters the bucket, and the level will rise or fall. Change the rate at which it leaks out, and the water level will rise or fall. The water entering the bucket is analogous to the sun. The greenhouse gases are like the the hole in the bottom of the bucket. They can’t close the hole, which some people seem to think AGW theory claims, but they can close it smaller to a certain extent. The only debate is over how much smaller they can close that hole and cause the water level, (or temperature), to rise.
“That energy is driven by a potential difference in the source. Heat operates in the same way, you need a difference in heat potential for heat to flow. So, if you transfer heat to something it will only transfer till a state of equilibrium is reached.”
Seriously, you guys need to actually study some thermodynamics. What Lindzen is claiming has nothing to do with what you are saying. Your argument is so wrong it is hard to know where to start.
The light bulb is not being heated by radiant or convective heat, it is being heated by an electric cirucuit that is quite happy to keep pumping in one watt of power for as long as that power source lasts. If no energy can escape from that system, it’s just going to keep getting hotter.
However, that external power source is a good example of a ‘forcing’, which so many people here fail to understand.
SJT,
You mean astronomical or volcanic tipping points?
You might be tipping one but I don’t think we are triggering one.
SJT
As captain Mannering would say to Jones “now you are in the realm of fantasy”
Not that you are far away from it, mind!
Alan, I do apologise; your little analogy is an elegant sucker punch; I misunderstood its purpose which was only revealed to me when SJT did his usual ‘fools rush in where angels fear to tread’ routine; on another post ender did his negative energy pitch; here we have SJT and the usual suspects doing their cosmic cube pitch; perpetual motion folks; step right up and get the perfect battery; something for nothing; I’ve referred to Zeno’s arrow before and infinite divisibility in the context of how AGW would depend on increasing amounts of CO2 to keep adding to the radiative imbalance in the atmosphere; that is defeated by, amongst other things, heat transfer mechanisms, and Stewart’s Law; well, this is the reverse; here we have an infinite incremental increase machine; the steady flow of energy into the ‘heat trap’ of Alan’s perpetual machine will, just like H G Wells’ waking sleeper and compound interest, eventually contain all the energy and heat in the universe! Actually the analogy is a timely reminder against tipping points and runnaway, the default positions of AGW; in the real world, as Gordon explains, nothing of the sort can occur; also in the real world, heat transfer negates any LTE becoming increasing hot or straying from thermal equilibrium; and with LTE’s not straying from thermal E, neither will the Earth (unless you have NASAGISS’s or CSIRO’s temp adjustment methods).
The concept of radiative equilibrium seems pretty easy to motivate, for an object floating in a vacuum:
According to the catechism, heat transfer occurs only via conduction, convection, and radiation. Conduction and convection are not possible across a vacuum, so heat can only get in and out via radiation. Therefore, thermal equilibrium in this context must mean radiative equilibrium.
What am I missing?
What am I missing?
Simply this – there’s no such thing as anthropogenic global warming (First Law of AGW Denial). And if it’s necessary to make nonsense of the Laws of Physics to prove that, then so be it.
The First Law of AGW Denial trumps all the laws of science as we used to know them; they’re no more than guidelines really.
mitchell’ “What am I missing?”
if you take in the whole system solid core and atmosphere from the top of the atmosphere outward all further heat transport is radiative but below this all factors play. The distribution of heat within the system is dependent on all the factors you mention with convection being the biggest player. Remember this is for heat transport within the atmospheric shell it doesn’t get it out to space.
mitchell’ “What am I missing?”
if you take in the whole system solid core and atmosphere from the top of the atmosphere outward all further heat transport is radiative but below this all factors play. The distribution of heat within the system is dependent on all the factors you mention with convection being the biggest player. Remember this is for heat transport within the atmospheric shell it doesn’t get it out to space.
Alan Siddons – “This notion originates from a long-ago misconception about how glass greenhouses work,…….”
What I am having the biggest problem with is reconciling your demonstrated knowledge of AGW and radiative physics with the actual body of knowledge. I mean you must have read something about and/or done it at school and to get you your present completely wrong ideas you must have completely misinterpreted it or not understood it so you fill in the blanks with made up stuff.
As Mitchell pointed out the Earth is considered for the purposes of thermal transfer to be the Top of the Atmosphere or TOA. At the TOA radiated energy is equal to the incident radiation. It has to be otherwise the Earth would warm or cool.
As for the rest are you the NZ guy that thinks the CO2 sinks to the ground because it heavy?
Ender
“As Mitchell pointed out the Earth is considered for the purposes of thermal transfer to be the Top of the Atmosphere or TOA. At the TOA radiated energy is equal to the incident radiation. It has to be otherwise the Earth would warm or cool.”
Is this from observation or,……thought.
Twisted physics. You’d heat the pocket of air around the bulb and/or the bulb itself. The fact is, most light bulbs already do this.
Of course, you should compact fluorescents; they don’t give off as much waste heat.
ender bender, Mr TOA;
‘At the TOA radiated energy is equal to the incident radiation. It has to be otherwise the Earth would warm or cool.”
I can think of 3 reasons why that would be wrong;
1. Whether the incoming featured more SW, X-Ray and UV, which has a greater warming effect than other radiation
2 Where the radiation was being emitted; “A 1C increase in the polar latitudes in the winter, for example, would have much less of an effect on the change of longwave emission than a 1C increase in the tropics. The spatial distribution matters.”
3 How much heat is wrapped up in Enthalpy; more LW may be going out but if there is a lot of moisture in the air, there will not be a linear reduction, if any at all, in temp.
Not knowing the physics but the NU-Physics, Ender and his looks decided to leave the dialectic.
What to make of it?
Oh, poor argument, what shallow basis you be based.
Mr. Siddons, allow me to explain your error. There are a number of different variables here, and you seem to be confusing them. These are:
Temperature: a measure of the average kinetic energy per molecule
Heat: a form of energy
Radiation: a form of energy, of which light is a subset
Blackbody radiation: the radiation emitted by an object due to its temperature.
Blackbody: a theoretical construct for an object that absorbs 100% of all radiation incident upon it.
Albedo: the percentage of energy diffusely reflected by an object. Does not include specular reflection. A blackbody has an albedo of 0.0
Now, the relationship between a blackbody’s temperature and the amount of blackbody radiation it emits is given by the Stefan-Boltzmann equation:
power emitted per square meter = sigma * temperature**4
where sigma is the Stefan-Boltzmann constant.
Radiative equilibrium is achieved when the amount of radiation emitted by a blackbody is equal to the amount of radiation absorbed by the blackbody. Let’s walk through the case of the earth.
First, we acknowledge that the earth is not a blackbody; it has clouds and snow and other sources of diffuse reflection. Its albedo is in fact about 0.30.
The amount of sunlight incident upon the earth is about 1366 W-m**-2 (this number is called the solar constant). We use the cross-section of the earth to calculate the total amount of solar radiation incident upon the earth:
collecting area = pi * (radius of earth)**2
= 3.14 *( 6.36 * 10**6m)**2
=1.27 * 10**14 m**2
so total solar radiation hitting the earth is
total solar radiation = solar constant * collecting area
= 1.37 * 10**3 W m**-2 * 1.27 * 10**14 m**2
=1.74 * 10**17 W
However, only 70% of this solar radiation is actually absorbed by the earth (albedo); the other 30% is reflected away into space. So the actual solar radiation absorbed is:
0.70 * 1.74 * 10**17 W
= 1.22 *10**17 W
For the earth to be in radiative equilibrium, it must emit this same amount of power. The amount it emits per square meter is given by the Stefan-Boltzmann equation, adjusted for the albedo (albedo applies to both incoming and outgoing radiation):
Power out = (1-albedo) * sigma * temperature**4 * emitting area
So we can invert this to solve for the temperature required to keep the earth in radiative equilibrium with the sun:
temperature = {Power out / [(1-albedo) * sigma * emitting area]}**-4
and since we know, because of radiative equilibrium, that the power out must be equal to the power in, we just plug in the value we calculated earlier:
temperature = { 1.22 * 10**17 W / [0.70 * 5.67*10**−8 W·m**-2·K**-4 * 4 * 3.14 * (6.36 * 10**6)**2]**-4
= 279K
Uh-oh! This is too cold! The earth’s average temperature is actually about 300K, not 279K. Why the discrepancy?
Answer: the greenhouse effect! Water vapor (the primary contributor to the greenhouse effect) intercepts some of the outgoing radiation and reflects it back to the earth’s surface. That increases the temperature of the earth’s surface to its actual value of 300K.
An additional note for those people who claim that variations in solar output are responsible for changes in the earth’s temperature: the Stefan-Boltzmann equation shows that a 1% change in solar output would result in only a 0.25% change in equilibrium temperature on the earth. You need a LOT of change in solar output to get much change in temperature here.
Maybe this other scenario will satisfy ender and SJT: use the physical equivalent of a blackbody itself. Despite possibly needed revisions that cohenite refers to, the operating principle of a laboratory blackbody is straightforward enough. Light is beamed into the tiny hole of a cavity whose interior bounces light around so much that it can’t get out and HAS to be absorbed. As a (near) perfect absorber, then, it heats up to the maximum level, thus setting an upper limit on radiant heat transfer. So simply insert a dichroic filter over that hole: visible light goes in but infrared can’t get out. Radiative disequilibrium.
Greenhouse theory insists that the temperature inside the cavity will rise higher than a filterless blackbody has ever seen. The internal temperature will keep climbing and climbing — one will have constructed a “radiant bomb.” I say that’s nonsense. The internal temperature doesn’t rise, only now you can’t determine that temperature from an observable Planck profile. But prove me wrong. Show me how to cook my dinner with a flashlight.
Surely the surface area (spherical) of the TOA increases as atmospheric temperature increases (expansion) and provides more radiative surface until balance is achieved. A quite small increase of the radius of a sphere gives a large increase for the surface area of the sphere. Runaway temperature increase of the atmosphere is simply not possible with a constant energy input. (OK the sun is hotting up, but very slowly)
“Greenhouse theory insists that the temperature inside the cavity will rise higher than a filterless blackbody has ever seen.”
Let’s assume that you have a theoretically perfect dichroic reflector: it reflects 100% of the incident radiation below a certain frequency. Then the temperature of the blackbody will rise — and here’s the important part — its peak radiative frequency will rise (as an object’s temperature rises, it goes from emitting infrared to dull red to red to orange to yellow to blue). At some point, the amount of energy ABOVE the critical frequency, escaping through the filter will equal the amount of energy coming in, at which point radiative equilibrium is achieved.
“Show me how to cook my dinner with a flashlight.”
BWAHAHAHAHAHAHA!!!
No, Chris, you haven’t got a handle on it. Only high-energy, high frequency light goes in, correct. But no thermal IR goes out. Radiative equilibrium states that the interior will thus surpass a standard blackbody temperature and will keep on climbing. Yet it doesn’t. Or else we’d have a source of inexhaustible energy, a magical furnace. Were it only so.
As for your long post, the atmospheres of all planets — all planets — show a dramatic temperature climb from 0.1 bar of atmospheric pressure and above. This occurs whether the planet has a “surface” to speak of or not and is independent of the atmosphere’s composition. “Greenhouse gases” are not involved. To 19th century thinkers, the earth’s near-surface temperature was a mystery. Well, guess what? It’s still a mystery. Because climatologists have been barking up the wrong tree for decades, never even imagining that earlier conjectures could be wrong. The old theory lacks evidential support and cannot withstand modern scrutiny. A new theory is demanded.
“But no thermal IR goes out.”
This is correct, but as the temperature of the blackbody increases, it starts to emit higher frequency radiation, and THAT radiation — not the IR — DOES escape.
“the atmospheres of all planets — all planets — show a dramatic temperature climb from 0.1 bar of atmospheric pressure and above. ”
You appear to be talking about the highest reaches of the atmospheres. This gets us into some very tricky thermodynamics, because these regions are transition zones between empty space and the lower atmosphere. Now, we can readily define the temperature of the lower temperature, but the temperature of empty space is a theoretically tricky issue, because there are actually three different ways of talking about temperature in solar space. The first is the 3K background radiation temperature. The second is the temperature of the solar wind, which is thousands of degrees K. Then there’s the temperature of the solar radiation, also thousands of degrees. The problem is, these latter components are at extremely low densities. At the junction between atmosphere and space, we have a disequilibrium situation where the concept of temperature is very misleading. Yes, the temperature you measure is really high. But comparing it to the equilibrium temperatures of the atmosphere below is very misleading, because you really are talking about apples and oranges.
And no, the surface temperature of planets is not a mystery, at least not to physicists. I just provided an explanation with calculations. Have you any objections to the calculation I carried out above?
No, Chris, I’m talking about the bottom — progressive heating with diminishing altitude. Having only hydrogen and helium available — and with 50.5 W/m² of solar radiance compared to 1368 W/m² — Jupiter acquires a higher atmospheric temperature than the Earth.
“the surface temperature of planets is not a mystery”
Dream on.
Jovian internal temperatures are driven by energy production in Jupiter. That’s why it’s hotter as you go deeper.
If you disagree with my claim that surface temperatures of planets are not a mystery, please state your disagreement. I have provided a detailed quantitative explanation of the surface temperature of the earth. You have not disputed that calculation. So, what do you dispute?
Chris,
Just one or two small points: you’re assuming that the outgoing albedo equals the incoming albedo. This is clearly wrong, as the wavelengths, reflectivity etc are different. In any case, if incoming albedo equaled outgoing albedo then you’d get the same temperature (279K) from your equation for any value of albedo between 0 and 100%.
Also, if the outgoing albedo remains constant then a 1% change in incoming albedo equates to a temperature change of about 1K. Has cloud cover remained constant to within 1% over the last century?
Lastly, over a 24-hour period the collecting area is doubled, because both sides of the Earth are irradiated, whereas the emitting area remains constant, equal to the surface area of the Earth.
This is significant, because the surface, heated by the Sun, retains that heat for a considerable time. If you double the collecting area you get a temperature of 331K,
Yes, Peter, that’s right: albedo is a highly variable notion. My calculation is an averaging calculation for the entire planet and it certainly doesn’t cover the whole story. For example, it assumes that the entire planet is isothermal — everything at the same temperature. That’s way wrong! My calculation is what’s called a “first-order” calculation — it takes into account only the most fundamental physical principles. However, Alan is questioning fundamental principles, and so the calculation shows what those principles are and how they operate.
There are a hundred ways to correct this first-order calculation: albedo varying both spatially and temporally; differential greenhouse effects (much weaker at the poles than in the equatorial regions); the fact that the earth rotates; the oceans as a thermal reservoir; and so on. But again, Alan is questioning the basic physics of radiative emission, a subject that has been nailed down well for more than a century (did you know that Einstein received his Nobel Prize not for relativity but for his contribution to blackbody radiation theory?)
Actually, what Alan is challenging is now known as the conservation of mass-energy; he rejects this statement:
“For the Earth to neither warm or cool, the incoming radiation must balance the outgoing.”
In other words, he’s saying that the thermal budget of the earth need not balance. The conservation of mass-energy is one of the fundamental laws of physics, and Alan is declaring that this law is wrong. Once again I ask the question: whom do you trust, scientists, or Alan?
Also, Peter, you’re correct in noticing that albedo cancels out in the first-order calculation. And another thing: the whole point of the greenhouse effect is that the albedo for sunlight is higher than the albedo for infrared.
Chris: “Jovian internal temperatures are driven by energy production in Jupiter. That’s why it’s hotter as you go deeper.”
The same could be said of the Earth. The core of the Earth is about the same temperature as the surface of the Sun, and we have molten rock a few miles beneath us. So what keeps the surface relatively cool? If there was no outgoing radiation then the entire Earth would still be a glowing ball of molten rock, and we certainly wouldn’t be around having this discussion.
Chris: “And another thing: the whole point of the greenhouse effect is that the albedo for sunlight is higher than the albedo for infrared.”
That would make the equilibrium temperature even lower than 279K
We’re not questioning the physics, we’re questioning the application (or mis-application) thereof
Peter, the energy production inside the earth is much, much lower than the energy production inside Jupiter. The earth’s energy production comes primarily from the decay of radioactive elements (there’s also a tiny amount of energy production from internal tidal friction). In other words, the earth is a huge nuclear reactor. However, the rate of energy production is extremely low. The only reason why the internal temperature is so high is that the earth’s mantle and crust are very good thermal insulators. The internal heat leaks out to the surface very, very slowly. I don’t have the numbers at hand, but this contribution to the earth’s surface temperature is negligible.
By contrast, Jupiter is generating huge amounts of energy, mostly by thermonuclear reactions in its core. It’s a bit smaller than the critical mass necessary to become a functioning star, but it still has a small amount of thermonuclear energy release going on inside. And a “small” amount of thermonuclear energy is still a very “large” amount of energy!
“That would make the equilibrium temperature even lower than 279K”
Oops, yes, I got it backwards: the albedo for sunlight is LOWER than the albedo for infrared. I keep confusing albedo-reflectivity-emissivity-absorptivity. Also, there’s the difference between the albedo of the surface of the earth and the albedo of the atmosphere. In any event, the basic concept still holds.
Chris Crawford,
You seem to know your physics. I have a question for you. Why not simply measure the energy incident upon the atmosphere (via satellite) and the energy radiated away (also by satellite) and subtract. The difference should give us the long term temperature trend on earth, right? Or what am I missing (besides a brain)?
The atmosphere (without the greenhouse effect) is also quite a good thermal insulator, meaning that the surface doesn’t lose heat as quickly at night as it would without an atmosphere. This, in itself, makes the equilibrium temperature greater than 279K
Steve, your question is a good one. We can do the first half of your suggestion: measuring incoming solar radiation. We’ve been doing that since the 1970s. However, the second half — measuring outgoing radiation) is the killer. You see, the amount of outgoing radiation depends on where and when. Dark surfaces, such as bare mountainsides, emit lots of radiation, while snow and ice emit much less. So which ones do you measure: the bare mountains or the snow? It gets even worse when you take into account cloud cover, which dramatically lowers emissions, and diurnal (day/night) differences. Suppose that you’ve got a big parking lot in the middle of the desert. All the dark, dark asphalt soaks up lots of sunlight and gets very hot, so it emits lots of IR. When the sun goes down, it continues to emit IR, but its temperature falls and it emits less and less IR through the night. So when do you measure its IR output: noon, sunset, sunrise, or midnight?
All these complexities make it impossible to carry out your experiment. But it’s a sound idea in principle.
“The atmosphere (without the greenhouse effect) is also quite a good thermal insulator, meaning that the surface doesn’t lose heat as quickly at night as it would without an atmosphere.”
The only form of thermal transfer from the earth to space is radiative. Yes, air is a good insulator for convective and conductive thermal transfer, and so it works great for insulating one part of the surface (say, the inside of your house) to another part (say, the outside of your house). That’s why double-pane windows work well.
However, the only place the earth can transfer heat to is space, and space has no matter to take the heat by convection or conduction. Hence the only means of thermal transfer is radiative transfer, and the insulation that an atmosphere provides for radiative transfer is what we call “the greenhouse effect”.
Chris: “the albedo for sunlight is LOWER than the albedo for infrared”
Has this been calculated exactly? For one thing, clouds have a high albedo for sunlight but a relatively low albedo for IR. Ice, which has a high albedo to sunlight has effectively zero albedo to IR – being on the surface. Both of these vary very considerably. Water vapor, which also varies very considerably, has a high albedo to IR but a low albedo to sunlight.
Chris,
Thanks for the reply. I see the devil is in the details as usual.
Chris: “However, the only place the earth can transfer heat to is space, and space has no matter to take the heat by convection or conduction. Hence the only means of thermal transfer is radiative transfer”
Exactly. Radiation is the only possible vehicle for heat transfer from the TOA into space. However, as you go lower through the atmosphere the role of radiation gets less and less, and that of convection becomes more and more. At the surface boundary layer it’s chiefly conduction.
Chris: All these complexities make it impossible to carry out your experiment.”
What makes it so difficult to measure this by satellite? Satellites cover practically the whole surface, both day and night.
Peter, our problem here is that albedo is truly a global notion that breaks down when you try to get specific. It’s easy to talk about the albedo of an entire planet — that’s where the notion originated. But when we start breaking albedo down by components, it gets confusing very quickly:
What’s the albedo of North America?
What’s the albedo of Utah?
What’s the albedo of Salt Lake City?
What’s the albedo of the Utah State Capitol?
What’s the albedo of the windowsill on the Utah State Capitol?
What’s the albedo of Utah at 9:00 local time?
What’s the albedo of Utah at midnight local time?
What’s the albedo of Utah when it’s snowing?
What’s the albedo of Utah when it’s raining?
What’s the albedo of Utah when it’s clear?
What’s the albedo of Utah in blue light?
What’s the albedo of Utah in red light?
What’s the albedo of Utah in infrared light?
As you can see, this gets horribly complicated. Albedo is really an aggregative idea that integrates all the pieces into one simple number. You can shift gears and talk about emittivity, absorptivity, reflectance, luminance, and so on — but that takes us even deeper into physics.
And when you try to measure it from space, you have to decide how to put all the different pieces together. How much weight do we give to Utah? How much weight to nighttime versus daytime? And so on. And how do you handle the anisotropy of the radiation (differing amounts in different directions)?
it’s been suggested that the end goal of the what-me-agw movement is to eliminate tha pst 500 years of scientific progress, but i’ve never before believed that explicitly.
well, since we’ve overturned conservation of energy, i’ll go invent a perpetual motion machine and get us out of the energy crunch.
Chris,
If the albedo cannot be measured then it can only be estimated.
And it’s not at all clear to me, given all the ‘horrible complications’, how it can be estimated to any degree of confidence.
The earth’s albedo in sunlight, considering only visible light, is best measured by measuring the brightness of earthshine on the dark side of the moon. This is where we get the figure of 0.30. However, this is not a bolometric (entire spectrum) measure, and it applies only to the sunlit earth.
Albedo is thus useful only for the first-order calculations. The calculations we actually use in the models are vastly more complicated and do not include a concept so gross as albedo.
Confine a lightbulb inside an infrared barrier (like a globular mirror) and electrically feed one watt to it. After a while, will it be generating the heat of a thousand watt bulb?
Imagine if a Watt was a unit of power and not energy and you had implied that you could add energy indefinitely to a lightbulb without heating it up, that would be embarrassing.
Chris Crawford,
since the radiative effect we are arguing over includes greenhouse gases, why do you use 6.36*10e6 as the radius to compute the radiative area instead of, say, the top of the stratosphere??
I would point out that the higher in the atmosphere a molecule is when it radiates, the lower the chance that the LR will strike the ground due to the smaller number of degrees the earth will occlude… The higher you are the less chance there is that the emitted radiation will strike another molecule unless it is going down…
Obviously I am not smart enough to quantify this. Can you help?
Another issue is that Climatologists, and many scientists, agree with your statement that internal heat of the earth is well insulated from the surface. With all the recent discoveries of underwater volcanos and vents, is there anyone looking into the possibility that the actual contribution to temps are a bit higher? One vent system in the Pacific was estimated to be heating BILLIONS of gallons of water a year. Also, the number of under water volcanoes estimated to exist has been increased.
http://environment.newscientist.com/article/dn12218-thousand-of-new-volcanoes-revealed-beneath-the-waves.html
http://www.indiadaily.com/editorial/1904.asp
http://news.xinhuanet.com/english/2008-06/23/content_8423894.htm
http://www.riverdeep.net/current/2001/02/021601_volcano.jhtml
http://www.nature.com/news/2006/060727/full/news060724-11.html
http://www.bobkrumm.com/blog/?p=1927
(how much ice could an eruption melt? The important point for me is NOT that volcanoes caused the Arctic ice to melt, they didn’t, but, just how much energy is involved in eruptions that heat the oceans)
Chris: “The calculations we actually use in the models are vastly more complicated and do not include a concept so gross as albedo.”
If you don’t use albedo in your calculations then why do you use it in your attempt to explain the physics to us?
Many of us are capable of understanding ‘vastly more complicated calculations’. Why not share them with us?
Chris: “The earth’s albedo in sunlight, considering only visible light, is best measured by measuring the brightness of earthshine on the dark side of the moon. This is where we get the figure of 0.30”
That’s the incoming albedo. The outgoing albedo cannot be measured in this fashion, and can only be estimated.
But this can only be estimated by using, as terms, the very parameters we’re trying to measure. This seems a bit of a topsy-turvy way of doing things.
SJT said…”The light bulb is not being heated by radiant or convective heat, it is being heated by an electric cirucuit that is quite happy to keep pumping in one watt of power for as long as that power source lasts. If no energy can escape from that system, it’s just going to keep getting hotter”.
In your comments, you are taking my comments out of context. I was responding to a post in the context of global warming theory that claimed energy would keep building up if it had no escape. I replied “there is more to it than that”. I was infering that we are not talking about an idealized system in which energy cannot escape. I was also making the point that heat flows from a higher potential to a lower potential.
Heat does not flow in an idealized or closed system on Earth. It is surrounded by an infinite sink whose mean temperature is slightly above 0 K. Any energy absorbed by the Earth from the Sun, will eventually find its way out to that sink. As far as the Earth is concerned it is at a higher heat potential and that heat is flowing to what might be termed a zero heat potential in the universe.
Greenhouse gases interfere with direct radiation from the surface, by absorbing the radiation, warming, and raising the surface temperature from about -19 C to +15 C. Eventually, that heat too will escape to the sink, so it is a temporary reprieve.
Most of the CO2 in the atmosphere is from natural sources (~97%) and should be part of the base greenhouse warming. Anything we humans have contributed is less than 3%. Considering that water vapour is ~1% of the atmosphere and CO2 ~3/100ths of the atmosphere, based on that ratio alone, CO2 should account for no more than 1.0 C warming, and that includes our pitiful contribution of <3%.
Heat radiated from CO2 goes up as well as down and laterally. Exactly how much is getting back to the surface? How much is being absorbed by water vapour and other CO2 molecules in the atmosphere and re-radiated, up, down and sideways?
This is a complex issue for which simplistic answers have been provided.
As I write this, I have become curious about something. The core of the Earth is alleged to be molten. It’s also a fact that the deeper you dig into the Earth, the warmer it gets. Where is that heat coming from…surely not from the Sun. What’s the possibility that the Earth generates some of it’s own heat from geothermal processes?
When I studied a bit of geology, we learned that the Earth is actually oblate, like a pumpkin. That shape apparently comes from the stress of the gravitational pull of the Sun the Moon. As the Earth moves in its orbit about the Sun, it is flexing due to those stresses, and cracks in the Earth heat up as they rub against one another.
There are estimates that the Earth’s core may be in the vicinity of 5,000 to 6,000 °C. That heat has to go somewhere. There is also a theory that the core may be turning at a differnt rate than the rest. There would be immense friction in that case, and immense heat generated.
Why not simply measure the energy incident upon the atmosphere (via satellite) and the energy radiated away (also by satellite) and subtract. The difference should give us the long term temperature trend on earth, right? Or what am I missing …?”
Triana,of course. The instrument has to be far enough away to see the whole disk of the earth at once. The thing you want has not on;y been designed, it has been built built, but it’s in storage for some reason.
Why not simply measure the energy incident upon the atmosphere (via satellite) and the energy radiated away (also by satellite) and subtract. The difference should give us the long term temperature trend on earth, right? Or what am I missing …?”
Triana,of course. The instrument has to be far enough away to see the whole disk of the earth at once. The thing you want has not only been designed, it has been built built, but it’s in storage for some reason.
KuhnKat, the atmosphere is very thin relative to the diameter of the earth. Most of the mass of the atmosphere is within, what 10 km of the earth’s surface, and the earth’s radius is 6000 km, so we can treat the effects you are mentioning as negligible. They’re real, to be sure, but their total effect will surely be tiny.
Yes, the discoveries of undersea volcanoes and heat sources (black smokers) have been a surprise, but their overall contribution to the heat budget of the earth is still negligible. For example, a big volcanic eruption might release 10**17 Joules of energy — about as much as strikes the earth as sunlight in one second. So you can see, vulcanism doesn’t really contribute much to the earth’s overall heat budget.
Peter suggests that I go through some of the vastly more complicated calculations involved in more detailed calculations of the earth’s heat budget. The problem here is that the next round of calculations takes us out of the realm of direct analytical calculation and into numerical solutions; in other words, you can’t just write some formulae, plug in numbers, and get numbers coming out. Instead, you start writing computer programs. And that’s getting us into REALLY hairy stuff.
And you’re right: there’s not much point in messing with albedo in any generalized sense beyond the first order of calculation. You *can* use it when you build an albedo function in a big computer program, which calculates the specific albedo of an area of surface based on its physical properties. So we could say that a chunk of Greenland has an albedo of 0.85, while a similar chunk of the Pacific Ocean has an albedo of 0.03.
Gordon Robertson inquires into the source of the high temperatures into the sun and then correctly speculates that tidal friction might be one source. However, decay of radioactive nuclei is considered to be the more important source, although I don’t have the numbers at hand. We can calculate the amount of energy coming from tidal friction by measuring the rate at which the earth’s rotation is slowing down.
You don’t understand physics or you wouldn’t have made such an inane argument. The system you describe is open (that is it consists of more then just the light bulb, the reflector and the gasses between the two).
If you could perfectly seal in the light bulb with this reflector the equilibrium temperature of the reflector + gasses inside the reflector + light bulb can be found by a black body radiation calculation based on the size of the reflector.
There are the added problems of ambient temperature and that is is not possible to create a perfect seal like mentioned so hot gasses escape and are replaced by cooler gasses.
Gordon Robertson says: “Most of the CO2 in the atmosphere is from natural sources (~97%) and should be part of the base greenhouse warming. Anything we humans have contributed is less than 3%. Considering that water vapour is ~1% of the atmosphere and CO2 ~3/100ths of the atmosphere, based on that ratio alone, CO2 should account for no more than 1.0 C warming, and that includes our pitiful contribution of <3%.”
There are a lot of mistakes here. First of all, we have contributed raised CO2 levels from about 280ppm to over 380ppm…a 35% increase. And thus, over 1/4 of the CO2 currently in the atmosphere is due to us.
(Your 3% statement comes from comparing the gross output from natural and manmade sources…but those natural outputs are balanced, in fact now more than balanced by uptakes, i.e. absorptions. The additional carbon from fossil fuels that we are rapidly liberating in the form of CO2, by contrast, is accumulating in the atmosphere. To give an analogy: Let’s say that you had a bank account with $10000 to which you were adding $1000 from your paycheck and taking out $1000 a week for your expenses, so it was staying steady at $10000 over the years. Then, let’s say I come along and start withdrawing $100 a week from your bank account. After about 2 years (100 weeks), I will have drained your whole account. However, using your logic, I could argue that I am responsible for only 10% of the drop in your account since you were withdrawing 10 times as much as I was.)
Furthermore, you can’t determine the amount of warming simply from the relative concentrations of CO2 and H2O. They have different warming potentials…and in fact very different absorption spectra. Besides, the amount of radiative forcing depends approximately logarithmically on concentration for the concentration regime we are in.
Gordon Robertson says: “Heat radiated from CO2 goes up as well as down and laterally. Exactly how much is getting back to the surface? How much is being absorbed by water vapour and other CO2 molecules in the atmosphere and re-radiated, up, down and sideways?
This is a complex issue for which simplistic answers have been provided.”
Provided by who? The radiative transfer calculations have been done. You may not have read the relevant works but that is not anyone’s fault but your own.
Louis – “Not knowing the physics but the NU-Physics, Ender and his looks decided to leave the dialectic.”
Actually I was taking the dog for a walk on the beach and generally interacting with my family.
I guess I should spend far more time on the computer.
Louis – Actually Louis I did not have to say anything – Chris did a far better job at explaining the physics that I would have done.
Thank you Chris.
Chris Crawford; your use of so much maths on a Sunday morning constitutes cruel and unusual punishment; nonetheless, I’m glad you have because you are wrong; the gist of what you have presented has been covered in Smith’s recent paper;
http://arxiv.org/PS_cache/arxiv/pdf/0802/0802.4324v1.pdf
Smith was seeking to rebut the Gerlich paper’s dismantling of the AGW concept of a greenhouse;
http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v3.pdf
As a digression it is beyond doubt that the atmosphere has an insulating effect but that effect is nothing like the misrepresentitive AGW greenhouse concept.
Where Smith has gone wrong is that he relies on average albedo, SB, temperature and ender’s funny TOA nonsense. AGW is based on these averaging and uniform concepts. Essex, McKitrick and Andresen have written a paper lampooning the concept of global average temp;
http://www.vogue.ca/~rmkitri/research/globaltemp/GlobTemp.JNET.pdf
Naturally Eli and the lads at Deltoid have jumped all over the Essex paper with some collegial but firm advice to Essex et al’s contumacious efforts; but Eli has been hoisted by his own petard; in a related post he rabbits on about LTE’s;
http://rabett.blogspot.com/2007/03/what-is-local-thermodynamic-equilibrium.html
A LTE is a discrete parcel of atmosphere gas with an internal uniform or average temp; as Chilingar et al show, such parcels of air are subject to abiabatic convective heat exchange with higher cooler air; the lower parcel is subject to Stewart’s Law which says that the GHG’s within that parcel will emit at the same rate as they absorb; as the parcel rises the emission will be upwards pursuant to the thermal gradient, thus defeating Philopona’s model’s obstensibly increasing downward LW; it is at this stage that the first nonsense of AGW’s greenhouse with its averages and uniformities becomes apparent; for it to be true all such LTE’s would similtaneously be going upwards and delivering their IR to space; this clearly is not happening; so what you say, TOA balance doesn’t require similtaneous convective uplift of all LTE’s; this is true and it is this point which really defeats TOA and AGW; SB determines the temp based rate of emission from the surface; SB, like temp is not unifrom (doh); a recent paper explores this aspect of the issue;
http://climatesci.colarado.edu/publications/pdf/R-=321.pdf
The paper says;
“The radiative temperature of the Earth is used by IPCC and CCSP to represent the portion of the radiation emitted at the top of the atmosphere which originates from the Earth’s surface. However, the outgoing long wave radiation is proportional to the fourth power of T [T4] from Stefan-Boltzman’s Law, not temperature itself. A 1c increase in the polar latitudes in the winter, for example, would have much less of an effect on the change of long wave emission than a 1C increase in the tropics. The spatial distribution matters, but this important distinction has been ignored. A more appropriate measure of radiatively significant surface changes would be to evaluate the change of the global average of T4 with time.”
Fortunately this has been done but before I turn to that let’s consider the ramifications of this for ender’s TOA radiative balance exingency; what this means is that a considerably greater amount of LW could leave Earth at the poles and still be matched by by less radiation coming in at the equator; conversely, a greater amount of radiation could be coming in at the poles and still be matched by much less radiation leaving at the equator, as expressed in the thermal response within the atmosphere. As I said a measurement of this discrepancey has been done;
http://motls.blogspot.com/2008/05/average-temperature-vs-average.html
Motl has compared the difference in Watt/m2 energy between the average of the fourth power of temperature and the fourth power of the average temperature (SB) as being 9W/m2; per unit of time this is a lot and is the equivalent, not only of the energy available for heat transfer between LTE’s (ie weather), but also a measure of the radiative imbalance which can exist before a global thermal disequilibrium occurs.
With such a radiative imbalance possible the greenhouse concept as promulgated by AGW is absolute garbage; but then so is AGW.
“Triana,of course. The instrument has to be far enough away to see the whole disk of the earth at once. The thing you want has not only been designed, it has been built built, but it’s in storage for some reason.”
We are about to spend trillions on carbon abatement and they won’t launch a satellite to see if it is necessary!? Me thinky, something stinky.
Thanks for the info.
Joel; the old shibboleth that isoptopic ratio decline is proof that the increase in atmospheric CO2 is attributable to anthropogenic sources is due for a bit of a dusting; Steve Short has done a lot of work to do with biomass depletion of CO2; anchillary to this is the fact that certain phyloplanckton are prone to feed on C13 CO2; as Julian Flood observed in an interesting post, “its not the production end which is causing the light C signal, its the extraction by oceanic biology.” Your post is also problematic when it says the natural flux of CO2 is in balance; this is patent rubbish as the hemispheric disparity indicates; CO2 is also not uniformly mixed as a look at global albedo and upward LW maps indicates;
http://www.exploratorium.edu/climate/atmosphere/data2.html
Obviously the CO2 from burning fossil fuels went to Venus.
cohenite, I have difficulty making sense of your writings; you sling around all sorts of impressive technical terminology, but the underlying physical reasoning doesn’t make any sense.
For example, you start off with this statement:
“I’m glad you have because you are wrong”
But then you don’t follow up anything addressing what I wrote; instead you refer to some rather oddball papers arguing over some basic physics that was pretty much worked out about 100 years ago — as if there really is some sort of controversy here.
First, let me point out something important: I presented first-order calculations. These kinds of calculations have only heuristic value: they’re good for laying out the basic physics for beginners, but they’re never what you would use for real-world analysis. It’s actually rather silly to argue about whether my earlier analysis is right or wrong, because it is neither: it’s first order. For real-world analysis, you carry out far more detailed numerical calculations.
You write:
“A LTE is a discrete parcel of atmosphere gas with an internal uniform or average temp”
Actually, the link you provide describes a condition called “Local Thermal Equilibrium”, which is a necessary condition for applying most thermodynamic laws. So there is no such thing as “a LTE”, and it is most certainly not a parcel of atmospheric gas.
This is why I have trouble making sense of your post; the terms are all jumbled around in random ways. So I’ll ask you to try to articulate your ideas in greater detail.
Here’s another example:
“as the parcel rises the emission will be upwards pursuant to the thermal gradient”
Say what? Are you saying that the radiative emissions from a parcel of air will be non-istotropic? And why in the world would the thermal gradient have any effect on the isotropy of the radiative emissions?
“…thus defeating Philopona’s model’s obstensibly increasing downward LW”
This comment does not appear to have any logical relevance to the rest of your comment, although I can’t be sure I understand what your topic is.
Your paragraph describing the point made by Mr. Motl regarding the difference between average T and average T**4: that point is valid but it seems silly to me to try to tweak a first-order calculation when what is needed is to make the jump to a proper numerical calculation using location-specific information. Another way of saying this is that Mr. Motl is arguing about what might be called the second-order calculation, when the second-order calculation presents us with nothing more than a somewhat better approximation than the first-order calculation. We shouldn’t rely on the first-order calculation for all our answers — it’s only to show the basic physics. Mr. Motl’s calculation takes into account an additional detail, but it’s still of little predictive value. There are a ton of additional details to take into account — why should differential T**4 be the most important factor to consider? In the end, we have to consider as many of these factors as we possibly can.
You conclude with what seems to me to be a total non-sequitur:
“With such a radiative imbalance possible the greenhouse concept as promulgated by AGW is absolute garbage; but then so is AGW.”
I think you’ll need to spell our your reasoning here. Your statement reminds me of an old cartoon showing two physicists at a blackboard covered with equations. At one place on the blackboard, the first physicist has written “and then a miracle happens”, with an arrow pointing to his grand conclusion. The second physicist is pointing to the ‘miracle’ note on the blackboard and saying “I think you need to make this step a little more explicit.”
It also reminds me of Cato’s concluding comment for every speech he made before the Roman Senate: Carthago delenda est: “Carthage must be destroyed” — even if his speech had nothing to do with Carthage.
cohenite – “As a digression it is beyond doubt that the atmosphere has an insulating effect but that effect is nothing like the misrepresentitive AGW greenhouse concept.”
So what does the insulation and please present the peer reviewed papers that describe and quantify this insulation effect independent of greenhouse gases.
“Motl has compared the difference in Watt/m2 energy between the average of the fourth power of temperature and the fourth power of the average temperature (SB) as being 9W/m2;”
No Motl said that if you calculate the emitted radiation and then average it you would be wrong however if you do the averaging first and then calculate the emitted radiation you get the correct answer. It is an artifact of not being able to add T^4. You nor anybody has been able to demonstrate in what calculations this error has been comitted. I challenged this the last time you brought this up and you failed to produce it then.
So you have 2 tasks this fine Sunday morning apart from learning maths. One isto find the peer reviewed papers quantifying the ‘insulation’ that you have made up and second to show where climate scientists are doing the calculations incorrectly.
Smith BTW is not wrong – that is the basic textbook physics that you would have to overturn with peer reviewed work of your own.
Chris; you have every right to be proud of your equations; as to your points; you need to read the Eli link again; LTE’s do exist; read the anonymous link in the comments; do you deny that there are vertical convective movements of discrete parcels of air which are internally temp consistent but differ from external air? If you do I suggest you take a ride in a plane and pray for turbulence.
I am not saying radiation is non-isotropic; the Philopona reference was for luke; as to the upward emissions point; look at this link, and thanks to JanP for providing it; I hope I’m interpreting it correctly;
http://www.climateaudit.org/phpBB3/viewtopic.php?f=4&t=268#p5125
The key statement is; “In a large part of the IR (eg 15u), at the ground, the upward IR (blue curve) exactly matches the downward IR. The nett heat transfer is zero. But in the window (eg 11u), the back radiation is zero. That is where the heat gets out.”
There is a net radiative escape, which happens to follow or create the thermal gradient.
Now, as to your obfuscation and cherry-picking; the Pielke paper (which you have ignored) clearly establishes that ender’s, and AGW’s, requirement for a TOA radiative balance, as ender defined it, is not necessary; in fact it is contradictory; and if a radiative balance does not cause a global heating response then what is AGW about? As to Carthage; it was defeated, was it not?
ender, I have no idea what you are talking about; Motl’s paper explains the difference between average temp and average SB; the difference is profound and is confirmed by the Pielke paper; and if you think I’m running around after you, you must be mistaken; the evidence is plain and the fact is, only your closed mind prevents you from seeing it.
“An additional note for those people who claim that variations in solar output are responsible for changes in the earth’s temperature: the Stefan-Boltzmann equation shows that a 1% change in solar output would result in only a 0.25% change in equilibrium temperature on the earth. You need a LOT of change in solar output to get much change in temperature here.”
If the equilibrium temperature is 286 degrees Kelvin, for example, than you are saying that the equilibrium temperature of the earth would increase by only about .72 degrees celsius.
This really is ridiculous and a failing testimony for the flat earth model you are working with.
Such a powerful increase in solar output would punch heaps of extra joules into the oceans leading to a cumulative response of the planet that wouldn’t top out for a very long time.
The oceans would warm, than the deeper oceans, which would inhibit heat transfer to the deeper oceans from the earths mantle. Leading to a heat buildup there as well.
The extra solar activity would enhance the shield to the cosmic rays leading to less cloud cover. This would magnify the effect. The buildup of joules would continue leading to a massive buildup of water vapour in the air which itself would magnify the effect.
The buildup of water vapour would indeed be so huge as to spread the water vapour around to areas that do not now have it. Pushing up average temperatures massively. As the climate system changed dramatically the night-time temperatures in previously frigid areas would increase allowing for more water vapour to be held overnight thus pushing up average global temperatures by massive amounts.
This is the problem if you are working on otherworldly models rather than concentrating on the world as it is.
What you are saying might be true for a flat earth, twice as far from the sun, that is a black body, where the water vapour is magically uniform throughout, where the planet cannot accumulate joules, and where it is noon all the time.
Get your feet on the ground and get back to the real world.
cohenite – “I have no idea what you are talking about;”
The last statement of the article is:
“There are two basic lessons to be learned from this exercise:
1. The impact of nonlinearities shouldn’t be neglected and climatology should carefully observe the evolution of the differences between climate zones; seasons; weather variations; regional changes of albedo; day-and-night differences.
2. In the calculations of forcings, it is not the arithmetic average of temperatures that should be substituted but rather the fourth root of the arithmetic average of the fourth powers of the (absolute) temperatures. In this way, the bulk of the problems discussed in the previous point – and in this whole article – can be circumvented.
And that’s the memo.”
Note point two the problems mentioned in the article can be circumvented if you do the sums properly which as far as I know all climate scientists do. Knowing the problems summing 4th powers the temperature is averaged first and then the radiative energy is calculated using the Boltzman equations. If you do it the other way round you get it wrong. Thanks heaps Lubos however I am sure that everyone knows this including Fermat .
For every section of the globe you can do independent calculations and take into account the polar regions that have a higher albedo and so on. Chris’s and Smith’s crude first order calculations uses 0.3 as the albedo for the whole Earth which is pretty close to the mark.
Large GCMs use small grids where as many factors as they can stuff into the calculations are done on a grid by grid basis taking into account the average temperature of the grid, the albedo, the estimate cloud cover, whether it is sea or land or ice and so on.
To make Lubos’s point you would have to show where the modellers are committing the mistake otherwise as Lubos himself says the problems can be overcome and the correct answer found.
If you don’t understand this then you have no business saying that Smith is wrong.
Stip: We are about to spend trillions on carbon abatement and they won’t launch a satellite to see if it is necessary!? Me thinky, something stinky.
Well, big policy sure looks necessary, but I agree with you about the satellite. Only sombody who had something to hide would oppose launching it if most of the costs had already been sunk, right?
NASA could launch the instrument and put the whole of climate science to some serious objective tests that it hasn’t gotten yet. It would help refine current knowledge if and when it’s valid or replace it with something better if and when it isn’t.
It turns out that it’s the global-warming-is-hooey crowd that has prevented the satellite from being launched, though. See, the original champion of the thing was Al Gore. They called it Goresat and accordingly went and “sat” on it.
You’d think they’d want us to lay our cards on the table, like that, but no, they seem to want to keep on betting.
===
http://www.desmogblog.com/how-politics-conspired-to-kill-dscovr
or
http://tinyurl.com/6s7zyq
The latest news is the most encouraging:
===
In a stunning break from years of inaction, the US Congress has tabled legislation ordering NASA to finally deal with the critically important Deep Space Climate Observatory (DSCOVR).
The National Aeronautics and Space Administration Authorization Act of 2008 was submitted last week to the House of Representatives. Section 207 of this Act is plainly entitled: “Plan For Disposition Of Deep Space Climate Observatory.”
If this Act becomes law, NASA must finally cough up some answers on why this vital piece of space hardware has been sitting in a box for the last seven years.
===
http://www.desmogblog.com/congress-orders-nasa-to-deal-with-dscovr
http://tinyurl.com/55723w
===
Thank you for supporting NASA’s traditional earth observation mission.
ender; you are a cherry-picker par excellence; you have ignored Pielke’s paper which proves Motl; the Pielke paper disproves your TOA assertion, which coincidentally happens to be the AGW paradigm; and which incidentally corresponds to Alan Siddon’s analogy of this thread; the atmosphere is the IR barrier according to AGW and the sun is the power to the light, Earth; hey presto, a cosmic cube; well done ender, all our energy problems are solved; just keep churning out CO2 to maintain the IR barrier.
Cool! Alan Siddons has persuaded god to repeal the Law of Conservation of Energy. (I wonder how you bribe a god to do something like that?)
That means perpetual motion machines are possible after all. Sweet.
Ender bender is trying to talk to people about science when he sings the virtues of Hives Hamilton. How Amusing.
David thats what all the ridicule is about right? The conservation of energy. Perhaps we would want to ask Alan if thats the case. If he believes he is violating that principle. Somehow I doubt it. And it would be worthwhile listening and trying to get a fuller picture of the angle Alan is taking. Whether its an entirely different paradigm. Or a different angle that fleshes out more standard assumptions.
Joel Shore said…”There are a lot of mistakes here. First of all, we have contributed raised CO2 levels from about 280ppm to over 380ppm…a 35% increase. And thus, over 1/4 of the CO2 currently in the atmosphere is due to us”.
Here’s the stats for the 1990’s from the US Department of Energy (DOE):
http://tonto.eia.doe.gov/FTPROOT/environment/057304.pdf (see p.26 – Table 3)
I don’t have the source at my finger tips for the emission of heat from GHG’s (up, down, lateral) but it’s a moot point since I was raising a hypothetical question. I do have the inference somewhere and I will keep looking. Meanwhile check this site for the irrelevance of anthropogenic CO2 density:
http://www.weatherquestions.com/Roy-Spencer-on-global-warming.htm#satellite-temps
Spencer claims that only 38 molecules of CO2 are found in 100,000 molecules of air. Your 380 ppmv pretty well corrobortes that. (i.e. 380 cups of CO2 per 1 million cups of air would be 38 cups of CO2 per 100,000 cups of air, or 38 molecules of CO2 per 100,000 molecules of air).
Considering the DOE table, that natural CO2 accounts for over 97% of all CO2 in the atmosphere and that 98% is reabsorbed, Spencer claims 1 molecule of human-made CO2 is added to 100,000 molecules of CO2 every 5 years.
He has other reasons for thinking the model-based AGW theory is wrong. For one, he’s an expert on MSU telemetry on satellites, having specialized in that at NASA. Now he works with John Christy and they claim satellite measurements are not corroborating model predictions. If you live by the arguement that the satellite data is wrong, please read what he has to say on the above URL.
Secondly, he thinks precipitation systems are behind the greenhouse effect and control it. Ultimately, he claims, the Sun drives the greenhouse effect based on the amount of available sunlight. Clouds affect the amount of available sunlight and are the Earth’s natural climate control.
correction on last post from Gordon Robertson @ 05:59 PM:
change “…Spencer claims 1 molecule of human-made CO2 is added to 100,000 molecules of CO2 every 5 years”.
to:
…Spencer claims 1 molecule of human-made CO2 is added to 100,000 molecules of air every 5 years.
Michael Tobis said…”Why not simply measure the energy incident upon the atmosphere (via satellite) and the energy radiated away (also by satellite) and subtract. The difference should give us the long term temperature trend on earth, right? Or what am I missing …?”
Michael…read my post at 05:59 and see second link. Spencer explains that satellite instrumentation is not sensitive enough to do that and that such calculations are purely theoretical.
Chris Crawford said…”Answer: the greenhouse effect! Water vapor (the primary contributor to the greenhouse effect) intercepts some of the outgoing radiation and reflects it back to the earth’s surface. That increases the temperature of the earth’s surface to its actual value of 300K”.
Chris…I mean absolutely no disrespect, but why did you cut off the math when it got to the good part? 🙂
I presume that if you had the math for that, you’d be in line for a Nobel.
Folks,
reread Irving Langmuire’s criteria for pathological science – AGW satsifies all of them.
Jennifer wrote: Confine a lightbulb inside an infrared barrier (like a globular mirror) and electrically feed one watt to it. After a while, will it be generating the heat of a thousand watt bulb? No.
When its temperature is consistent with the input, further heating stops.
It’s like water seeking its own level. Lacking any means to radiate to its surroundings, the lightbulb merely gets as hot as a watt of power can make it, which is not much hotter than what it would be in the open.
———
You’re still putting energy in, right? But it’s not getting out. So it’s staying in there as heat. Add more energy, get more heat. Forever (assuming you have a perfect heat shield).
Where do you think the energy is going at the point that it “gets as hot a a 1 watt bulb can get”? You’re still adding more energy – where’s it going if it’s not radiating? Into a box? Turning to fairy dust? Teleporting back to hades?
Where’s it going?
This post is so utterly idiotic I have a hard time believing it’s real. If you keep adding energy to a system, without letting the energy leave the system, the system’s energy will increase. This is not complicated.
Magpie; the idiocy is that AGW is built on a similar analogy to your’s; you confuse a shield with storage, and a constant supply of energy with an increasing rate of supply; as a thought experiment there’s no doubt the concept needs some further information, such as; is the surround a non-quantum unit of space; is it in a non-vacuum; if so then it becomes similar to, but not identical with a greenhouse, because the photons cannot escape; heating of the space will be subject to entropy with that forming a balance with the constant rate of energy coming in; since the energy supply is constant, as is the enthropic response, per unit of planck time there cannot be an overall increase in accessible microstates, and therefore temperature.
Magpie: “Where do you think the energy is going at the point that it “gets as hot a a 1 watt bulb can get”? You’re still adding more energy – where’s it going if it’s not radiating? Into a box? Turning to fairy dust? Teleporting back to hades?”
Firstly, the whole argument about the lightbulb is ridiculous and has no analog in the real world.
As the temperature increases the electrical resistance increases, so less power is dissipated.
If the temperature rises to beyond the melting point of the filament, the light will stop working.
Having dispensed with that, if it’s heat energy you’re pumping in and not electrical energy, the temperature cannot increase beyond the temperature of the heat source.
Any analogy that starts with conflating temperature, energy and power is destined to fail. This was an epic fail.
There’s too much stuff to deal with properly here, but I would like to address an important point: cohenite, I have great difficulty responding to your comments because they contain so much garbled terminology. Let me give you some examples:
You confuse Local Thermodynamic Equilibrium (LTE), a condition that is required of a parcel of air if we are to apply standard thermodynamic laws to it, with the parcel itself. If you want to talk about the parcel of air, call it a “parcel of air”.
You ask: “do you deny that there are vertical convective movements of discrete parcels of air which are internally temp consistent but differ from external air?”
Of course not! Vertical motion of air is the driver of much of our weather. But such vertical motion is not to be confused with Local Thermodynamic equilibrium, nor with anisotropy of radiation.
On the matter of anisotropic radiation, you link to a very nice article explaining clearly and in great detail the radiative processes in the atmosphere. The article, however, does not say that parcels of air emit radiation anisotropically; it instead explains how radiation that started on the ground and is moving upwards is affected differentially by the atmosphere. He is describing, in technical detail, the greenhouse effect. Yes, radiation does escape; if it didn’t the earth’s temperature would rise monotonically. The key idea here is that the obstruction to radiation presented by greenhouse gases raises the temperature until a new equilibrium is reached at a higher temperature.
Here’s another example of garbled terminology:
” the Pielke paper (which you have ignored) clearly establishes that ender’s, and AGW’s, requirement for a TOA radiative balance, as ender defined it, is not necessary; in fact it is contradictory; and if a radiative balance does not cause a global heating response then what is AGW about?”
Here you use the term “radiative balance” — I believe you mean “radiative equilibrium” — but in fact radiative equilibrium is really just a version of the conservation of energy. Are you denying the conservation of energy? And how could the conservation of energy be contradictory. WHAT is it contradicting? And what is a “global heating response”? Do you mean “increase in average global temperature”?
Over the centuries scientists have learned that, without precisely-defined terminology, you end up with confusing, muddled arguments like this one. Science has developed a jargon of precise terms that are rigorously defined. Sometimes you don’t use those terms; and sometimes you use them incorrectly. Please, if we are to sort out our differences, we need to first sort out our terminology.
Gordon Robertson, I think that the problem with your reasoning arises from the belief that the concentration of CO2, measured in parts per millions, is so tiny as to be impossible to create large effects. Yes, CO2 concentration in the atmosphere is only 380 ppm. But tiny concentrations aren’t negligible concentrations. Taipoxin, a snake venom, kills if its concentration in the bloodstream exceeds 2 parts per billion. CO2 concentrations can have a big effect even at concentrations as low as 380 ppm. It might not seem like much, but you just follow the math.
You do raise an excellent point in asking how I ascribe the discrepancy between the first-order calculation of earth’s equilibrium temperature and the earth’s actual temperature to the greenhouse effect. You’re right, I didn’t follow through on the calculations. I won’t go through them here because they get us into some more complicated physics, but I’ll present the results: CO2, all by itself, at the concentrations we’re seeing, should cause a temperature increase of only a few degrees K at most. If there were no other forces at work, anthropogenic emissions of CO2 would not pose a serious threat to the climate for at least a century. The real fight concerns the possibility that the overall feedback mechanism is positive. That is, CO2 will raise temperatures slightly, which will cause more CO2 to be released naturally, which will cause even higher temperatures, which will cause even more natural CO2 to be released naturally, etc. There’s plenty of controversy here. This is important! There is no controversy (except among the ignorant) as to whether CO2 by itself can raise global temperatures. Nor is there any controversy about the fact that, by itself, CO2 will not raise temperatures by much. The real controversy concerns the relative magnitudes of the differing feedback effects. Some of those feedbacks are positive and some are negative. The evidence suggests that the overall feedback system is positive, meaning that a small increase in CO2 concentrations will ultimately lead to a large increase in temperature. But there is room for people of good faith to argue about the magnitudes of these feedbacks.
Have you considered what would happen if the properties of the infrared barrier gradually change?
Of course, you could argue that the concentration of GHGs in the atmosphere cannot increase indefinitely. I don’t even mean that planetary resources are finite, or that we’ll all be dead at some point. Theoretically, even if our emissions remain constant, some new point of GHG concentration equilibrium should be reached eventually. But maybe that’s way too far into the future.
In the end, it’s a pointless exercise. We end up arguing about the eventual magnitude of the effect, and that’s already pretty much what the argument is about.
I’m disappointed to see how far afield the discussion went. But that’s the nature of evasion, isn’t it? I provided an experimental test for progressive heat-gain due to radiative disequilibrium: Dichroic filter over a laboratory blackbody. Visible goes in, no infrared goes out. Progressive heat-gain will not occur — otherwise we’d have a magical furnace. Just bleed off the interior heat every so often and you have a miraculously cheap oven or boiler on your hands.
http://www.ilovemycarbondioxide.com/ipcc_oven.html
Radiant energy is a heat source. When an object’s temperature corresponds to the amount of energy feeding it, heat transfer stops. Only sunsettommy got the point. Radiative equilibrium is a fiction.
Alan, your thought experiment is nonsense because you confuse heat, temperature, and power. You set it up as a light bulb emitting one Watt of power. You then ask whether its power output will increase to 1000 Watts. Yes, the temperature will rise, but temperature isn’t power. That’s why your idea is nonsensical.
He’s not saying that at all Crawford.
Of course, if it’s just one watt-femtosecond and no more, then you’ll not get an increasing amount of heat. But the light won’t shine. If the light continues to shine, for a watt-hour, for example, the heat will rise throughout that hour.
Alan, did you mean “calorie” instead of “watt?”
Ed, be careful on your units here. A Watt-second is one Joule. A Joule is a unit of energy and a Watt is a unit of power.
Chris, I have no idea why you’re so obtuse. 1000 watts per square meter radiated on a blackbody will raise it to 364 Kelvin. That’s it. You could radiate that power for a million years and you’ll still have 364 Kelvin. W/m² do not accumulate and temperature doesn’t blow up like a balloon. When temperature corresponds to heat input, heat-transfer stops. A laboratory blackbody subjected to 1000 W/m² does not become a “heat bomb” if its infrared emission is suppressed. Radiative equilibrium is thus a provably false concept, which means that you have no empirical support for anything you’re alleging. Doesn’t this BOTHER you?
Alan Siddons said:”Just bleed off the interior heat every so often and you have a miraculously cheap oven or boiler on your hands.”
If we assume perfect insulation for the container, it will cost exactly the same to heat up the volume of air inside the container to a certain temperature, whether you use a small power source for heating, like your 1 W light bulb, or a large one, like a 1000 W electric heating element, as commonly found in commercial electrical ovens. The only difference is that the large power source will heat it up quicker. Power (unit: W = J/s), put simply, is a of measure energy (unit: J) per time unit (unit: s). So running your 1 W light bulb for 1000 hours will introduce the same amount of energy into the volume of air of your perfectly insulated container as running the 1000 W heating element for 1 hour: in both cases, you spent 1 kWh of energy (3.6*10^6 J), which will be converted into heat. And since the energy company charges you per kWh, you pay the energy company the same in both scenarios. So you won’t have a miraculously cheap furnace, just a really slow one.
You dismiss your conclusion of ever increasing temperature as absurd. Well, you’re right, but not because there’s some made-up balance between the heat and the power input. No, it’s simply because in real life, we don’t have perfect insulation, which is why real ovens don’t keep getting warmer and warmer, but have a maximum temperature.
So I hope I’ve made more clear what the difference is between power and energy, and why confusing the two has led you to draw false conclusions. Really, this is basic, basic physics, so you may want to lay off making such strong physics claims until you understand even these basics.
Alan, again you are using your terminology in a way that confuses things. I will attempt to rephrase your comments in a form that is rigorous, and I think that you’ll see that your reasoning is flawed.
You write: “1000 watts per square meter radiated on a blackbody will raise it to 364 Kelvin.”
A more rigorous statement of that idea is:
A blackbody in equilibrium at 364K will radiate 1000 Wm**-2, and so will require a thermal input of 1000 Wm**-2.
You write: “W/m² do not accumulate and temperature doesn’t blow up like a balloon.”
No, power per unit area does not accumulate but heat energy does, and as the heat energy of a reservoir increases, its temperature increases. Hence, if you pump energy into an isolated system, its temperature will increase monotonically. Remember, I’m talking about an isolated system — that means that it has no other inputs or outputs. If you’re talking about an open system, such as a blackbody in free space, then it will come to an equilibrium temperature at which its radiative output is equal to its heat input. I carried out this calculation for a simplified version of earth to show how it’s done.
You write: “When temperature corresponds to heat input, heat-transfer stops.”
This is a somewhat sloppy way of stating what I wrote above [‘ it will come to an equilibrium temperature at which its radiative output is equal to its heat input’]
You write ” A laboratory blackbody subjected to 1000 W/m² does not become a “heat bomb” if its infrared emission is suppressed.”
What do you mean by “suppressed”? Do you mean “completely blocked”? If so, what band of frequencies are you specifying? This sloppy terminology renders your statements meaningless.
“Radiative equilibrium is thus a provably false concept, ”
Inasmuch as your previous statements are vague and indefinite, you certainly haven’t proven anything. Please, try to express yourself in the precise terminology of science.
Chris Crawford’ it was your verballing, cotton-picking, cherry-picking mate, ender, who said;
“At the TOA radiated energy is equal to the incident radiation.”
And you condone this because I use the word balance instead of equilibrium? Nit-picker; how many types of picking can you guys do?
I said I wasn’t promoting anisotropic radiative transfer; the article I link to shows that there is a net upward flow, not downward; argue with it not me since you seem to think it supports the AGW greenhouse; and like ender you have once again ignored the ramifications of the Pielke paper; a gross figure for an ‘imbalance’ of radiative transfer at the TOA doesn’t mean global heating; even if one allows for CO2 interception of IR to the extent that AGW demands.
“The evidence suggests the overall feedback is positive”; for gawds sake, you must be joking.
Congratulations to Chris Crawford for his extremely clear and accurate explanations of fundamental physics. Alan Siddons et al should be grateful that a person of Chris’s ability and patience is willing to spend the time to point out where they are mistaken. Alan’s thought experiment with a perfect insulator is an interesting one, but the conclusions he draws are incorrect.
cohenite writes: “”The evidence suggests the overall feedback is positive”; for gawds sake, you must be joking.”
No, I’m quite serious. If you’d like to discuss the various feedback mechanisms, I’d be happy to explain those. However, we should start with the largest factors and work downward from there.
cohenite – “and like ender you have once again ignored the ramifications of the Pielke paper”
That would be a bit hard as your link does not work. I think however RC also posted something on this and their link to it does not work either. However here is some of the text from their discussion:
“Recently, Roger Pielke Sr. came up with a (rather improbably precise) value of 26.5% for the CO2 contribution. This was predicated on the enhanced methane forcing mentioned above (though he didn’t remove the ozone effect, which was inconsistent), an unjustified downgrading of the CO2 forcing (from 1.4 to 1.1 W/m2), the addition of an estimated albedo change from remote sensing (but there is no way to assess whether that was either already included (due to aerosol effects), or is a feedback rather than a forcing). A more appropriate re-calculation would give numbers more like those discussed above (i.e. around 30 to 40%).
But this is game anyone can play. If you’re clever (and dishonest) you can take advantage of the fact that many people are unaware that there are cooling factors at all. By showing that B explains all of the net forcing, you can imply that the effect of A is zero since there is nothing apparently left to explain. Crichton has used this in his presentations to imply that because land use and solar have warming impacts (though he’s simply wrong on the land use case), CO2 just can’t have any significant effect (slide 18). Sneaky, eh?”
I think that RC did not agree with the Peilke paper either, if this is the right one, I guess they did not really read it either.
And also here are a comment reproduced in full from the same post on RC
http://www.realclimate.org/index.php/archives/2006/10/attribution-of-20th-century-climate-change-to-cosub2sub/#more-355
“Roger Pielke Sr Says:
4 October 2006 at 10:24 PM
Hi Gavin- Thank you for your reply to #7.
With respect to your comment on the fractional contribution of methane, I used the information from http://www.pollutiononline.com/content/news/article.asp?DocID=%7B92402192-8574-45C2-8319-32A75F1E8ECE%207D&Bucket=Current+Headlines&VNETCOOKIE=NO that stated,
“According to new calculations, the impacts of methane on climate warming may be double the standard amount attributed to the gas. The new interpretations reveal methane emissions may account for a third of the climate warming from well-mixed greenhouse gases between the 1750s and today. The IPCC report, which calculates methane’s affects once it exists in the atmosphere, states that methane increases in our atmosphere account for only about one sixth of the total effect of well-mixed greenhouse gases on warming.”
Were your conclusions misrepresented?
On the magnitude of the radiative forcing of CO2, if the fraction of the radiative forcing attributed to the well-mixed greenhouse gases of methane is increased, and the total radiative forcing of the well-mixed greenhouse gases is unchanged, the fractional contribution attributed to CO2 must decrease. Are you thus suggesting that the IPCC value for the total of the well-mixed greenhouse gases needs to be increased to a value above 2.4 Watts per meter squared (the IPCC figure is presented, for example, at http://darwin.nap.edu/books/0309095069/html/3.html) ?
Finally, there is also the issue of time over which these radiative forcings have been increasing. CO2 has been a significant radiative forcing since the industrial period began, while the large increase in the input of black carbon into the troposphere, for example, has been more recent. If this is so, the “global average temperature” has responded (i.e. equilibrated) to a fraction of the CO2 that was input in the earlier years, such that IPCC Figure overstates the current contribution of CO2 to the global average radiative forcing (since that Figure presents a difference between preindustrial times and 2000, not the current radiative forcing). In the preparation of our 2005 NRC Report, the estimate in our discussions was that a value of 80% is a reasonable estimate of the added CO2 since preindustrial times which has not equilibrated.
I do agree with the theme of your post on the arbitrary aspect of attributing specific numbers to each of the radiative forcings.
However, it is an important issue to estimate the fractional contribution to positive radiative forcing due to CO2. If it dominates the other radiative forcings (and other “non-radiative climate forcings), than policy actions that focus on CO2 make good sense. However, if it is only one of several important radiative forcings, such as I summarize on Climate Science (in the hyperlinks for my weblogs given in #7), and, if we also need to be concerned about the spatial scales of the radiative forcing as is presented in
Matsui, T., and R.A. Pielke Sr., 2006: Measurement-based estimation of the spatial gradient of aerosol radiative forcing. Geophys. Res. Letts., 33, L11813, doi:10.1029/2006GL025974.
http://blue.atmos.colostate.edu/publications/pdf/R-312.pdf,
as well as the “non-radiative” forcings as reported in the 2005 NRC Report “Radiative Forcing of Climate Change: Expanding the Concept and Addressing Uncertainties”,
than the emphasis of CO2 alone is an inadequate recommendation for us as scientists to give to policymakers.
[Response: When in doubt, read the original paper (Shindell et al, 2005) – figure 1 is extremely clear. On the second point, if you change the forcing attributed to one gas, why should the total remain the same? There are no constraints of the total – it’s merely the sum of the individual contributions. Why the line-by-line calculation of forcing by CO2 should be affected by our atmospheric chemistry calculation is a little puzzling… IPCC used an abundance based calculation for the current forcings and that’s fine. Our point was that for emissions reductions in the future, it helpful to know the forcing associated with each emitted component, so that targets can take account of atmospheric chemistry changes too. However, CO2 remains the largest single component and is the one with the largest projected growth, and while there is a lot that can be done to reduce the other forcings, the climate change problem in future is in many ways a CO2 problem. You and I clearly disagree on that, and that’s fine, we should however be able to agree on 20th Century forcings. -gavin]”
As you can see Roger Peilke is not in doubt of the effect of CO2 only the magnitude. The argument is about climate sensitivity not whether CO2 is a greenhouse gas.
ender bender; you could drive someone to drink; here is the Pielke link;
http://climatesci.colorado.edu/publications/pdf/R-321.pdf
Now, I repeat very slowly, I did not suggest or say or in any way shape or form that CO2 did not absorb IR radiation; I just totally disagree with the AGW model of forcing for the absorption which occurs; and I probably disagree with the AGW mechanism of absorption, including the capacity, whatever that is; and I disagree with the EG theory of positive feedbacks, whatever they are. Got it?
Chris has shown amazing patience here; as I discovered on the CO2 accumulation thread, trying to debate Alan is like trying to wrestle with Jello. Once again, Alan cannot keep clear the difference between the rate of change of something and the level of something, so his arguments are quite often literally meaningless.
I’ll try to restate some of Chris’ arguments in different wording that might make it more clear to others.
Point 1: The only significant energy interaction between the earth/atmosphere system and the rest of the universe is through thermal radiation. Any other mechanisms are completely trivial in magnitude.
Point 2: The only significant source of energy into the earth/atmosphere system is solar radiation. Internal radioactive decay and tidal friction effects are very small comparatively and can be ignored in the first-cut models like we are talking about here.
Point 3: The First Law of Thermodynamics (“conservation of energy”) tells us that for any system we define, the difference between the power transfered into the system and the power transfered out of the system is equal to the rate of change of the internal energy of the system. This is at root a simple accounting problem, like balancing your checkbook. If you have $1000/month coming in and $900/month going out, your checkbook balance is increasing at a rate of $100/month.
Note: This is true for any system you define. Some defined systems are easier to work with than others, and some provide more insight than others. Students spend much of an introductory thermodynamics class learning to define useful systems. I will choose the entire earth/atmosphere system so I am dealing with power transfers across the top of the atmosphere (TOA).
Point 4: It is possible for a change in internal energy to take many forms, but the only form significant for our purposes here is a change in temperature. Substances have “thermal capacitances” defined such that the rate of change of temperature is equal to the net power input to the substance divided by the thermal capacitance.
Combining the above points: Since the earth/atmosphere system only interacts energetically with the rest of the universe through radiative transfer in both directions, the difference between the total power transfer in and the total power transfer out is equal to the change in internal energy of the overall earth/atmosphere system. (If you insist, you could add a small fraction of 1 W/m^2 power input to the system for radioactive decay in the earth’s core, but this would not change the argument.) Such a change would manifest itself as a change in temperature.
In the special case where the incoming and outgoing power transfers are equal, the change in internal energy is zero, and temperature would not change. This is the case of “radiative equilibrium” (and it is in fact based on the laws of thermodynamics, not contradictory to it).
Jim Hansen of GISS recently claimed to have quantified an average radiative imbalance with a flux density of 0.85 W/m^2 +/-0.15 W/m^2. I’m extremely dubious of these numbers, but for the sake of argument, let’s say his upper limit of 1.0 W/m^2 is correct. This means that, on average, each square meter of the earth is taking in 1 Watt more power than it is giving off. In one second, each square meter is accumulating 1 Joule of energy, in each hour 3600 Joules of energy, and so on.
As the earth accumulates this energy (remember that energy is power multiplied by time) its temperature goes up. As its temperature increases, its own thermal radiative output will increase. This very basic property means that the earth/atmosphere system will tend toward radiative equilibrium — it may never actually be in radiative equilibrium because too many things are always changing, but it definitely tends toward it.
Alan’s points of confusion are many. In addition to confusing rates of power transfer with levels of internal energy and resulting temperature, he is confusing systems that can easily radiate away energy with those whose radiative output is blocked. The results are very, very different.
If I had a slab with one square meter of surface area that was free to radiate as a black body to outer space, and I were pumping 1000W into the slab (think of a heat sink on a satellite’s power source), if it started below 364K, it would be radiating less than 1000W away, and would start to increase in temperature. As its temperature increased, its radiative power output would increase, until when it reached 364K, it would be radiating just enough power away to balance the input, and its temperature would hold constant.
However, anything that you did to inhibit that radiative output (remember that a “blackbody” is the perfect radiator) would result in it reaching higher temperatures. In theory there is no limit to the temperature reached if you had total inhibition of outgoing radiation (and no other thermal path output), but in the real world, you cannot get this total inhibition, and besides, something would “give” first.
A real-world example that I had to deal with this month. On a new power-electronic product, the designers (despite my orders) put a thin cosmetic metal sheet over the heat sink that draws the heat out of the power transistors. Initial thermal testing on the prototypes showed the power transistors getting alarmingly hot. They came to be with their concerns, and I told them to take off the cosmetic metal sheet and repeat the test. Lo and behold, the power transistors reached thermal equilibrium at a temperature 20K (36F) lower than before. (Yes, there was some convective as well as radiative inhibition, but there would have been a substantial change from radiative inhibition alone.
Alan says, “Show me how to cook my dinner with a flashlight.” Alan’s obviously never had a sister or a daughter, or he would be familiar with the “Easy Bake Oven”, which uses a light bulb for cooking. I remember being stunned as a kid that my sister’s Easy Bake Oven actually could bake things.
cohenite – “ender bender; you could drive someone to drink; here is the Pielke link;”
Thanks for the link howevert that is Pielke whingeing about the surface temperature record not anything to do with greenhouse gases – whats your point?
“I just totally disagree with the AGW model of forcing for the absorption which occurs;”
Well you can disagree until you are blue in the face (or drinking again) however unless you post some actual physics that backs up what you say your really are just pissing in the wind.
All the physics from real physicists says you are wrong and nothing you have written or posted confirms what you say.
I couldn’t resist putting in a small post (at the end of a busy day) because I’m really glad that some people here truly believe in thermodynamics, at least in the gas phase!
As a specialist in solution phase chemo-thermodynmics (up to melts) I’m sure y’all would have noticed my difficulties in convincing steven watkinson of the over-riding importance of solution phase thermodynamics (;-) ahem.
While the thread debate is floating around radiative effects in the atmosphere I thought I’d just pop in the following recent reference of 15 August:
http://www.sciencemag.org/cgi/content/abstract/321/5891/946
I have a copy on order. There is also another fascinating paper which came out in July on the synergistic effects of aerosols and clouds (using those neat remotely controlled mini-aeroplanes to image clouds up close) but I have lent the journal with the reference to it to a colleague. Will post it when he gives it back.
“Well you can disagree until you are blue in the face (or drinking again) however unless you post some actual physics that backs up what you say your really are just pissing in the wind.
All the physics from real physicists says you are wrong and nothing you have written or posted confirms what you say.”
No thats bullshit and lies Ender. The claims of the alarmists don’t come direct via radiative physics but are instead mediated by outrageous aggregations and simplifying assumptions.
Lies don’t count Ender.
Curt your sisters easy bake oven was backed up by the mains. The mains were generated by extremely hot coal fires turning huge turbines.
I’m not sure I understand all of what Alan is saying but you don’t want to dismiss any of it until you are clear as well with exactly what he means.
“As you can see Roger Peilke is not in doubt of the effect of CO2 only the magnitude.”
If the effect is there but tint you crowd are still science frauds. Roger still works off the failed paradigm. But he’s a scientist so he doesn’t ignore the data.
”
“Recently, Roger Pielke Sr. came up with a (rather improbably precise) value of 26.5% for the CO2 contribution.”
Supposing Rogers right? 26.5% of bugger-all isn’t a great deal. And not enough NOT to be a GOOD THING.
Alan Siddons,
“Confine a lightbulb inside an infrared barrier (like a globular mirror) and electrically feed one watt to it. After a while, will it be generating the heat of a thousand watt bulb? No.
When its temperature is consistent with the input, further heating stops.
It’s like water seeking its own level. Lacking any means to radiate to its surroundings, the lightbulb merely gets as hot as a watt of power can make it, which is not much hotter than what it would be in the open. If not, we’d be able to generate incredible temperatures very cheaply. Just confine, wait, and release.”
Can I clarify this?
You propose a system that has energy being added to it at the rate of 1 W. This system is enclosed such that no IR can escape, furthermore that all the IR is reflected back into the system.
In this system, is energy allowed to escape by other means: non-IR radiation, convection, or conduction?
When you say “not much hotter than what it would be in the open”, how much is “not much”? Insignificant? Measurable?
(Of course we’ll assume that our bulb can carry on converting electricity into heat and light regardless of its temperature and that the IR mirror can be 100% perfect.)
Where the hell did this flaming nonsense come from?
Conservation of energy is a.) the first law of thermodynamics and b.) the very foundation of physics since at least Newton.
Or perhaps you believe that your computer there – the one you’re using to post this claptrap – is being run by nano-mice in a microscopic treadmill?
Hang your head in shame (or at least remove this rubbish so those of us with better things to do don’t have to spend the next few years giving you a basic education)
“Progressive heat-gain will not occur — otherwise we’d have a magical furnace.”
I must have missed the part where someone claimed that global warming is progressive heat-gain. Warming will stop at some point. The infrared barrier does make a difference, though.
Why not use a more apt analogy, such as the car with the windows rolled up vs. one with the windows rolled down?
Graeme, you say, “Curt your sisters easy bake oven was backed up by the mains. The mains were generated by extremely hot coal fires turning huge turbines.” It could do the same thing with a small battery bank. (You are trying to invoke a 2nd-Law limitation that you don’t understand and that is irrelevant here.)
The point is that by putting the bulb in a small, very well insulated chamber, you can get temperatures far higher than the same bulb outputting the same number of watts in an open space (say, hanging from a chain in a big open room).
I understand well what Alan is trying to argue, and it is complete nonsense. I teach this stuff at the university level, and students often come in with these types of misunderstandings. But they do not leave (with a degree, at least) if they keep believing these things.
Curt,
I can only say: read some more of this thread.
Joseph; the car analogy is explored here;
http://junkscience.com/Greenhouse/Kondis-Greenhouse.html
Steve; thanks for the link; if I understand it correctly it is backing up the Spencer-Lindzen work on clouds being a -ve feedback except when at high levels. Chris have you read it?
TrueSceptic, you say, “read some more of this thread.” To what end?
Actually, I have read the entire thread, much of it more than once, and much of it in total disbelief. I’m considering using parts of it for the next time I teach, so I can play “spot the fallacy” with my students.
Cohenite, I looked at the abstract and it looks very interesting but I do not have access to the journal, so I can’t read the full paper.
Chris; me neither; perhaps Steve will forward it to Jennifer.
Just getting back to Alan’s thought experiment of a light bulb in a container; I’ve already referred to this paper;
http://arxiv.org/ftp/arxiv/papers/0805/0805.1625.pdf
Robitaille seeks to distinguish Stewart’s Law from Kirchhoff on the basis of the nature of the surround/cavity and any body within it. I’m wondering whether for purposes of whether there is an incremental temperature build-up within Alan’s container that distinction is necessary; grappling with work and entropy and planck unit of time, it seems to me that per planck unit of time (PUT) the work done by the energy introduced into Alan’s cavity by the light will be matched by entropy such that the second PUT energy supply will be starting from scratch; which is to say there is no storage possible of energy to sustain an incremental increase of temperature PUT; this would hold regardless of the nature of the cavity walls and any thermal gradient and radiative direction because the work of the radiation will be the same whether done by absorption, reflection or remmission.
Cohenite, why on earth are you introducing the Planck unit of time into this discussion? That’s a purely theoretical construct that has no direct bearing on this problem. And, by the way, at 10**-42 sec, it’s very tiny .
By the same token, what on earth is a “second PUT energy supply”? What is a “temperature PUT”? Why do you need to use such weird concepts when the basic concepts are all you need to address the issue?
Chris; ok; just look at the Robitaille paper, Stewart’s Law, work and enthropy.
Cohenite, I just skimmed through the Robitaille paper, and it’s pretty weird. In the first place, note that it was not published in a peer-reviewed journal; it appears that it was never published anywhere. That’s always a bad sign.
But what’s REALLY wrong with the paper is that it is disputing an issue that was made obsolete more than 100 years ago! Stewart’s Law and Kirchoff’s Law were both attempts to explain blackbody radiation using classical physics. Classical physics didn’t work — blackbody radiation under classical physics should, theoretically, yield impossible results. The problem was resolved by none of than Albert Einstein who introduced the quantum nature of radiation. He won the Nobel Prize for that work.
Thus, the Robitaille paper is irrelevant to modern physics.
Chris; the paper’s conclusion makes it plain that the application of Stewart’s Law is consistent with the Planck and Boltzman constants, so I don’t understand your point about the quantum nature of radiation; Stewart’s Law is completely relevant to AGW since it deals with the process of absorption and emission and the consequences for temperature which flow from that.
As to the paper being published; my understanding is that it was, but I will check on that.
Chris Crawford said…”Yes, CO2 concentration in the atmosphere is only 380 ppm….”
Chris…the 380 ppmv is not what I am refering to as tiny. More than 97% of that 380 ppmv is from natural sources, and 98% is reabsorbed. Less than 3% is anthropogenic and that’s what I’m calling tiny.
Still, Roy Spencer calculates that only 38 molecules of CO2 exist in 100,000 molecules of air. I presume he subscribes to the anthropogenic CO2 being less than 3% because he also infers that only 1 molecule of anthropogenic CO2 is added to 100,000 molecules of air every 5 years.
I presume as well that he is taking 97% of 38 molecules to get about 1 molecule of CO2 that is anthropogenic. Where he gets the 5 years I don’t know but it must have something to do with the 98% reabsorption. No matter what, most of that 380 ppmv is accounted for in the greenhouse effect already.
The 380 ppmv to which you refer may be significant, and Roy Spencer and John Christy claim it ‘should’ warm the atmosphere. They are claiming, however, that the warming is not showing up in their satellite data sets. We simply cannot ignore that.
Spencer and Christy are no dummies and they are genuine climate scientists in the sense they studied atmospheric physics as undergraduates, then as a graduates, then as a Ph.D’s. Others, like James Hansen came at it through other disciplines like astrophysics and I really don’t think they have the in-depth understanding of the atmosphere as Trenberth, Christy or Spencer.
Anyway, Spencer was bright enough to work for NASA as an expert on satellite MSU units and I am more willing to listen to his analogies about CO2 in the atmosphere than I am a Hansen or Schmidt.
Curt,
Sorry, but you are being rational, logical, and reasonable, and that is an exercise in futility when dealing with some of the GWSceptics here.
Gordon Robertson.
in your post of 19 Aug, 20:42, you said:
“…the 380 ppmv is not what I am refering to as tiny. More than 97% of that 380 ppmv is from natural sources, and 98% is reabsorbed. Less than 3% is anthropogenic and that’s what I’m calling tiny.
Still, Roy Spencer calculates that only 38 molecules of CO2 exist in 100,000 molecules of air.”
You seem to be imputing that the 380ppmv value is larger than the value ‘calculated’ by Spencer.
Is this so?
“Chris…the 380 ppmv is not what I am refering to as tiny. More than 97% of that 380 ppmv is from natural sources, and 98% is reabsorbed. Less than 3% is anthropogenic and that’s what I’m calling tiny.”
Nonsense. Without humans the equilibrium level should hover around 280 ppmv. The fact that most of the increase in the CO2 concentration in the last 150 years is anthropogenic is evident from the data.
http://residualanalysis.blogspot.com/2008/08/just-in-case-there-are-any-doubts-about.html
Gordon writes:
“More than 97% of that 380 ppmv is from natural sources, and 98% is reabsorbed. Less than 3% is anthropogenic and that’s what I’m calling tiny”
Perhaps you are misinterpreting Mr. Spencer; perhaps he is mistaken; in any event, the statement as written is manifestly incorrect. The concentration of CO2 in the atmosphere before the Industrial Revolution was about 280 ppm. It has increased to 380 ppm in the 150 years since then. No natural mechanism for this increase has been discovered; the only plausible source is humankind.
Gordon said: “Chris…the 380 ppmv is not what I am refering to as tiny. More than 97% of that 380 ppmv is from natural sources, and 98% is reabsorbed. Less than 3% is anthropogenic and that’s what I’m calling tiny.”
So by your own figures, 3% is man-made, and 2% is not reabsorbed. Doesn’t that mean that humans produce 150% of the unabsorbed CO2? Compared to the unabsorbed CO2, the human contribution isn’t tiny at all then.
Chris Crawford: kudos for your patient and clear comments. Do not despair that your debating opponents are completely immune to reason, do it for the lurkers!
WRT the 3% man-made CO2 argument, it is a standard talking point, I debunk it here.
This has been an intertaining and illuminating thread, I must do a post of my own on it!
Jennifer, you reveal too much of your motives by hosting this and many other examples of transparent and brazen crackpottery. As one who claims to be a scientist and interested in exploring the truth you should be ashamed of your contribution to the disinformation campaign.
Thanks, coby. Some of the people here are pretty reasonable, but there are a few people with, um, strong feelings on the matter who soil the discussion with nastiness. I would prefer that Jennifer enforce higher standards of civility, but I realize that would take a good deal more effort on her part, so I have no basis to complain.
missing a link in my previous coment:
http://scienceblogs.com/illconsidered/2006/03/natural-emissions-dwarf-humans.php
The anthropogenic source of the increasing CO2 is not as straightforward as you guys backslapping would suggest; Steve Short has done some good work on cynaobacterial depletion of CO2, on vast scales; an interesting aspect of this is the reduced levels of C13 in the atmosphere as the putative marker of anhtropogenic sources; certain species of the phyloplanckton will eat proportionately more C13 than other types; this predisposition has a volcanic context in that the dust from eruption can impact on availability of zinc and chromium so that the phyloplanckton generically become C4, C13 eating. Roy Spencer also has an interesting take on the C13C12 ratio decline, which is the stock answer to the alleged human imput; he also notes that interannual co-variability in SH SST temperature is sufficient to explain the increase in CO2 levels; certaintly, with a 20thC dominated by EL-Nino +ve PDO’s and a dominant solar imput until the last half of the 2othC, there are plenty of reasons why the sea should be a net emitter;
http://wattsupwiththat.wordpress.com/2008/01/28/spencer-pt2-more-co2-peculiarities-the-c13c12-isotope-ratio/
The real issue is whatever CO2 increase is attributable to humans (and Spencer concedes some is), and the evidence suggests it is much less than Hansen’s hysteria would have it, that CO2 increase was accompanied by world wide increases in the standard of living; in short, the civilising of life-style; as Lomborg proves, by any reasonable measure, humanity has progressed; the extra CO2 has been well spent; or do you guys really advocate that we should have stayed in some semi-agragrian paradise which only exists in the febrile imaginations of people like Clive, we are not happy, Hamilton?
I have a little meta-discussion here for anyone interested…
http://scienceblogs.com/illconsidered/2008/08/making_lemonade.php
Thanks for the entertainment!
cohenite, there’s an interesting issue here regarding cause and effect. One of the great fears regarding CO2 emissions is that there is strong positive feedback. That is, an initial release of CO2 by humankind raises the temperature, which results in a larger release of CO2 from natural sources, which then starts the vicious circle going. And in fact, many AGW opponents have inadvertently supported this by emphasizing that CO2 concentrations in previous warming periods followed temperature rises — in other words, an increase in temperature caused release of CO2.
It may well be that the positive feedback has already started. There is no question that CO2 concentrations are rising, and at an increasing rate. Some of that rise is surely due to human activity. But we may have already started the ball rolling, and we may well see even faster acceleration of CO2 concentrations due to natural releases.
Chris;it sounds as though you are in the apocalypse camp with some sort of degree of runnaway in mind; I and other writers have intimated that CO2 increase following a causal, natural temperature increase (and thanks for that concession, although it is a fairly ubiquitous one at this stage with even such pro-AGW sites as Skeptical Science conceding it), may actually, through its own radiative absorption mechanism (a controversial point I concede but one which deserves more than the usual ‘nu-physics’ derogation), and through its causing massive negative feedback via Steve Short’s cyanobacterial activity, cause a cooling of the intiating temperatures which caused the CO2 increase in the first place; as Steve puts it;
“If it is essentially water vapour which amplifies CO2 then, in the broad scale oceanic weather effects i.e. SST, albedo, RH and lapse rate, cyanobacterial primary activity (driven by CO2+N+Fe+Si fertilization – the latter 3 volcanically affected -) we have the perfect candidate phenomenon for:
1 holding back SH temperatures (esp. SSTs) relative to NH;
2 holding back SH CO2 levels relative to NH
Adding to this is Spencer’s and Lindzen’s work on the stochastic, negative feedback of clouds; not to mention the decline in RH as a response to increased CO2, an effect already observed;
http://landshape.org/enm/greenhouse-thermodynamics-and-gcms/
The Minschwaner and Dessler paper attached to the above link showing a decline in RH correlated with an increase in CO2 is particularly interesting; now, the decline in RH is a crucial point for the enhanced greenhouse because it relies on RH increasing;
http://www.climateaudit.org/?p=2567
Mad props to Chris for having the patience to take this argument seriously. Next time I find myself teaching I am going to put Alan’s flashlight oven question on an assignment. What is the maximum temperature that can be reached by a perfectly insulated body being heated at a rate of one JS^-1?
Andrew, here’s a couple of references to get your poor students going;
http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Archives/Science/2007_July_6
http://www.physicsforums.com/showthread.php?t=173417
At the Wiki one click down to the Spherical Mirror discussion; now, I’m stumped; so what is the answer, without involving swartzchild radius’s?
Chris Crawford…maybe you can get a different interpretation out of this data:
http://tonto.eia.doe.gov/FTPROOT/environment/057304.pdf
See page 26, Table 3.
Somebody is wrong somewhere, my friend. That data above is for CO2 emissions and sinks in the 1990’s. If that is a decadal trend, I’d like to know where the evidence came from that we were at 280 ppmv prior to the industrial era, unless the 100 ppmv increase was mostly natural CO2.
I don’t have the expertise to query the figures. I do know that the 280 ppmv is based on ice cores and Jaworowski, an expert in the same, is hotly disputing that figure. He claims the extremely high pressure at depth in ice affects the isotopes, especially if the ice has been exposed to water. He also feels that the machinery extracting the cores affects the ice.
Jaworowski feels that 280 ppmv figure could be 30 to 50% higher than it is. After the Mann hockey stick debacle, I don’t have a whole lot of faith in proxy data.
I can provide you with at least one other scientific source in which it is stated that anthropogenic CO2 accounts for no more than 5% of all CO2 in the atmosphere. That paper was released by the Canadian government, and the body releasing it is pro AGW.
In fact here it is. I am cherry picking here because of the inaccuracies in the report and the outright embarrassment of it:
http://www.ec.gc.ca/climate/4th_Report_on_CC_e.pdf
see page 25, right hand column. They even attribute that to the IPCC. It says:
“The scientific consensus, as reflected by the
Intergovernmental Panel on Climate Change
(IPCC), is that incremental GHG emissions
caused by human activity since the Industrial
Revolution are having a discernible impact on
the climate. In the IPCC’s view, while human
activity may cause only about 5% of global
GHGs (with natural processes accounting for the
remainder), it is enough to upset the delicate
balance of GHGs in the atmosphere and, by
extension, the climate. The result is the
continued warming of the atmosphere and
resulting changes in its composition”.
Seriously, Chris, rather than suggesting an expert like Spencer is wrong, I suggest you check it out. I’d be interested in what you have to say.
This is not a contest to me regarding who’s right and who’s wrong. it’s an investigation, and I respect your academic background.
Chris Crawford:
“It may well be that the positive feedback has already started. There is no question that CO2 concentrations are rising, and at an increasing rate. Some of that rise is surely due to human activity. But we may have already started the ball rolling, and we may well see even faster acceleration of CO2 concentrations due to natural releases.”
Strictly and technically totally untrue!
The ‘official’ NOAA global mean CO2 concentration plotted on a monthly basis has been rising at a smooth rate of 0.45% per year over the 26 year period January 1982 – end March 2008.
I have the data directly from NOAA and am willing to post the spreadsheet anywhere or email to anyone.
The best fit to the curve has the equation y = 0.0423 exp(0.0045x) where y = atmospheric CO2 (ppmv) and x = time (in years). R^2 = 0.9951 i.e. this curve explains 99.51% of the variance of the data over the period 1982 – 2008.
Gordon Robertson,
5% of global GHGs is *not* 5% of atmospheric CO2. We do not directly alter the amount of water vapour, for instance.
Gordon, the confusion here arises from the difference between flux and equilibrium. You are looking at Table 3, which shows that natural emissions of greenhouse gases amount to 770,000 million metric tons, while human emissions amount to only 23,100 million metric tons. You look at that difference and conclude that human emissions are insignificant. The difference lies in the fact that there are ALSO natural processes that are removing CO2 from the atmosphere.
This problem — confusion over the difference between flux rates and equilibrium values — has cropped up many times, so I’d like to take a few moments to explain it. Flux rates are the rate at which something is coming into a system or going out of that system. If the incoming flux rate exceeds the outgoing flux rate, then the system builds up more and more of whatever is coming in. In almost all cases, however, higher and higher levels of the stuff induce higher outgoing flux rates. Thus, if the incoming flux rate exceeds the outgoing flux rate, then the level builds up until the outgoing flux rate is once again equal to the incoming flux rate, and equilibrium is re-established.
Let’s walk through an example. Suppose that we have a small river with a spillover dam. (A spillover dam is a low dam that is designed so that water will spill over its top.) The input flux of water is 1000 kg per second. We’re at equilibrium, so the output flux is also 1000 kg per second. Suppose now that there’s a rainstorm and the input flux increases to 1500 kg per second. The output flux is still 1000 kg per second, so the reservoir behind the spillover dam gains water at the rate of 500 kg per second. This causes the water level of the reservoir to rise. As it rises, more water spills over the top, increasing the output flux. This process continues until the output flux is once again equal to the input flux. When the rainstorm stops, the input flux falls back to 1000 kg per second, but the output flux of the reservoir remains at 1500 kg per second, causing the reservoir’s level to fall until equilibrium is re-established.
So we’ve got several concepts here: the input flux, the output flux, and the amount of water, which in this case we call the height of the water level in the reservoir.
Now let’s apply the same reasoning to the CO2 situation. It’s 1000 CE and we have an input flux of 770,000 million metric tons coming from natural sources only, and no anthropogenic CO2 emissions. We’re at equilibrium, so we have an output flux of 770,000 million metric tons. Now along comes the Industrial Revolution, and suddenly humans are adding 23,100 million metric tons to the input flux. Now the input flux is 793,100 million metric tons, but the output flux is still only 770,000 million metric tons. So the CO2 level in the atmosphere starts to rise. It will continue rising until equilibrium is reached, and the output flux is 793,100 million metric tons — but that will require a higher level of CO2 in the atmosphere.
Thus, even though the anthropogenic contribution is CO2 is much smaller than the natural component, it is the primary — possibly the sole initial — source of the INCREASE in CO2.
Steve, I’m relying on IPCC Figure 2.3, which starts a bit earlier — 1970 — than your data. When I draw a line connecting comparable beginning and end points, I get the data in the middle years falling slightly below the line. If we really want to resolve this question, the best approach would be to compare the least squares value of a best fit line to the least squares value of best fit parabola. My hypothesis is that the parabola would have a slightly better fit. However, I admit that the effect is still very small.
When you write “Strictly and technically totally untrue!” you are asserting that the temporal derivative of CO2 concentration is equal to 0.0000000… ± 0.000000000… ppm/yr. Don’t you think that’s a rather strong statement?
Oops! Correction! Steve, you’re NOT saying that the temporal derivative of CO2 concentration if 0.000 etc; you’re saying that it is less than or equal to 0.000 etc.
And by the same token, I’m saying that it’s greater than 0.000 etc.
I’m very disappointed in you Chris. You seem to enjoy engaging in totally over the top, verbose sophistry.
I simply presumed you are familiar with calculating the fixed compound interest over time on a loan, or how to calculate Net Present Value (NPV) of something appreciating at a fixed annual rat into the future?
I simply presumed you have done some high school or university math?
The exponential function is of course the standard means of calculating such rates of growth (or decay) of a parameter relative to some unit of time e.g. year.
So, when I say to you, in all good faith, that a line of best fit for the period 1982 to 2008, encompassing the last 26 years, for the rate of growth of the atmospheric partial pressure of CO2 can be expressed by the function y = 0.0423exp(0.0045x) = 0.0423 exp(0.45x/100) where y = atmospheric CO2 (ppmv) and x = time (in years), I am simply finding an exponential fit for the data which is no different from the way appreciation, or depreciation, is commonly estimated/computed in our respective societies.
The constant 0.0423 simply converts the units, the coefficient 0.0045 (or 0.45%) on x (time) is the actual annual rate of growth. The value of R squared (R^2 = Coefficient of Determination) is a precise measure of the overall proportion of the variance of the data which is explained by that fit.
Any reasonable person would accept that an R^2 of 0.9951 (99.51%) indicates an excellent fit.
The simple fact is, that to a very high level of precision, we CAN say, in all fairness, that the atmospheric partial pressure of CO2 grows (‘appreciates’ if you will) at the fixed rate 0.45%/year, to a high level of precision!
Presumably you live in the USA, the land of free enterprise, a nation I know very well indeed (and am very fond of).
That you don’t seem to understand the simple mathematical principles behind compound growth, interest, appreciation, depreciation etc is rather shocking (and dare I say it – revealing)!
0.4500±0.0011% (1 s.d.)
Steve, I wrote that CO2 concentrations were rising at an increasing rate. You wrote that this was “Strictly and technically totally untrue!”, then you proceeded to show the math that it was in fact rising at an increasing rate (exponentially). I rebutted the first statement when in fact you had already rebutted it quite thoroughly. My mistake was in giving priority of significance to the first statement.
But what really disappoints me is the nasty tone of your writing. I have stayed on here for some time because I believed that men of good faith could disagree in a gentlemanly and civil fashion. It didn’t bother me that a few individuals soiled the debate with nastiness. But of late the discussions here seem to be all heat and no light. You had been one of the few I could disagree with in a constructive fashion, but now you too have succumbed to the viciousness that seems to infest this blog. That, along with the other outbursts of verbal nastiness, convinces me that I am wasting my time here, because there is nothing to discuss. There are only arguments among people who have already made up their minds. And I have more important things to do than engage people who seek only to prove themselves by means of verbal combat.
Goodbye, and good wishes.
No, CO2 IS increasing by an INCREASING AMOUNT (in absolute terms) but it is NOT an increasing RATE (i.e. the RATE is not increasing).
A RATE is a ratio of one thing to another. It is an instantaneous measure of the ratio of one measurement (at a point in time) to another measurement (by definition at the same point in time). In this case, the RATE (e.g. ppmv/year, %/year etc) is the ratio of the amount which CO2 increased over e.g. 2005 to the mean level of CO2 in 2005 (NOT the level in 1970).
Wikipedia: Rate (mathematics), a specific kind of ratio, in which two measurements are related to each other.
A rate is a special kind of ratio, indicating a relationship between two measurements. A rate may be defined using two numbers of the same units resulting in a dimensionless quantity (for example, “1 in 10 people”), or may be defined by two different measurements with different units (for example, “metres per second” used in speed).
Often rate is a synonym of rhythm or frequency, a count per second. Examples are heart rate or sample rate.
Wiktionary: # (statistics) A measure of the frequency of a given event.
If you had said that CO2 was rising by an increasing amount each year (in absolute terms) then I would not have picked you up. BUT YOU DID NOT SAY THAT. YOU SAID:
“There is no question that CO2 concentrations are rising, and at an increasing rate.”
Then you got angry and said again:
“Then you proceeded to show the math that it was in fact rising at an increasing rate (exponentially).”
Each of these ARE incorrect statements. It is not my fault that you are unable to, or won’t, distinguish in your language between an absolute amount and a rate. They are not at all the same thing and I was certainly not taught in school that they were.
You should ask yourself if we are here just as a passive audience to quietly say nothing when you either unwittingly or deliberately use misleading or incorrect language.
I note that you are the first to require (nay demand) precision of meaning and expression from others.
Surely, the least you can do is apply the same standard to yourself.
It has nothing at all to do with ‘nastiness’.
Steve Short said…”The ‘official’ NOAA global mean CO2 concentration plotted on a monthly basis has been rising at a smooth rate of 0.45% per year over the 26 year period January 1982 – end March 2008″.
Steve…I have read that as well. CO2 was expected to rise exponentially but that proved to be false. In fact NASA GISS made a statement to the effect that 40% of the CO2 they expected went missing. They have assumed it was absorbed by sinks.
So Steve, why don’t you now describe a fixed rate? You know, 1 ppm/year increase. Because it sure seems correct to me to use “increasing rate” synonymously with “exponential rate”. Your intellectual gymnastics above do not change the accepted usages.
Chris Crawford said…”Gordon, the confusion here arises from the difference between flux and equilibrium”.
Chris…I am aware of the concept. It was one of our problems in calculus, where a bucket is filling with water at one rate and draining at another rate.
I get frustrated at times when people (not refering to you directly) dismiss atmospheric scientists like Roy Spencer while clinging to every word of mathematicians like Gavin Schmidt. Please consider what I said previously.
I agree that atmospheric CO2 has a density of 380 ppmv, although I am basing my agreement purely on faith for now. 380 ppmv is like saying 380 cups of CO2 per million cups of air, and on a molecular level it breaks down to 38 molecules of CO2 per 100,000 molecules of air.
Spencer points that out, then he goes on to claim that humans add 1 molecule of CO2 to 100,000 molecules of air every 5 years. You claimed he is wrong but you don’t explain why. I know where he gets the 1 molecule of CO2, it comes from multiplying 38 molecules by 0.03, which is the percentage of human-produced CO2 in the atmosphere. So, the contribution of anthropogenic CO2 is 1 molecule per 100,000 molecules of air.
So far, Spencer has been correct. He goes on to say humans contribute 1 molecule of CO2 per 5 years. That’s where the calculus comes in. The DOE paper is just for the US but it shows a 98.5% reabsorption of CO2, with 1.5% extra left in the atmosphere. It does not say how much of that is anthropogenic. Spencer has somehow calculated that the 98.5% reabsorption allows for the adition of only 1 molecule of anthropogenic CO2 every 5 years. Given the DOE data, why is that such a stretch?
Using your own argument of flux vs steady state, the atmospheric density of CO2 has apparently risen 100 ppmv in about 300 years. Much of the human-introduced CO2 has been recycled. AGW theorists have attributed all of that to anthropogenic CO2, even though extensive deforestation and ploughing of land has taken place. No allowance has been given for out-gassing from the oceans and the theory is based largely on proxy data. In fact, the base of 280 ppmv is contested.
I appreciate math, but sometimes you have to put the calculator away. Look at the problem. Humans are adding 1 molecule to 100,000 molecules of air. How much heating comes from that? I realize only 1% of the atmosphere is water vapour, but as Spencer points out, it’s the involvement of water vapour in precipitation systems that leads to the warming (and cooling), not the 1% itself.
Now look at the satellite record. It is showing roughly a 0.25 C lower atmosphere warming since 1979 and literally no net warming since 1998 (Lindzen claims 1995). A May 2008 paper has suggested not to expect warming till 2016 due to the Atlantic and Pacific oscillations.
Why do you suppose the lower atmosphere is not warming nearly to the extent predicted by the AGW theory? And how do you explain that warming has essentially leveled of for 10 years, a period which may extend closer to 20 years if the May 2008 study is correct?
The thing that bothers me most, however, is the out and out activism of James Hansen and NASA. In 1998, he had to admit he’d made an error, even though he blamed the computer, which he programmed. He immediately justified his error by claiming it served to make people aware of global warming.
He has made other errors as well even though he seems to be coming back to earth with more modest temperature predictions. That has not stopped him preaching gloom and doom based on remote theories of the ancient past.
AGW was an interesting theory that got way too much press and credibility from over-zealous scientists in the IPCC. Not many scientists have the guts to stand up to them, but here’s what John Christy has to say:
http://news.bbc.co.uk/2/hi/science/nature/7081331.stm
I think the vast majority of scientists owe this guy an apology.
Steve Short, if you *really* want to go into pedantic mode…
“So, when I say to you, in all good faith, that a line of best fit for the period 1982 to 2008, encompassing the last 26 years, for the rate of growth of the atmospheric partial pressure of CO2 can be expressed by the function y = 0.0423exp(0.0045x)”
The graph of an exponential function is not a line. A line can not be expressed by an exponential function. Told you I was going to be pedantic.
“The constant 0.0423 simply converts the units, …”
Then why didn’t you give the units of this constant? Without units, you suggest it’s a dimensionless constant, and that won’t change the units at all. Your not a physicist or an engineer, are you? They tend to be rather fanatical about units.
“…, the coefficient 0.0045 (or 0.45%) on x (time) is the actual annual rate of growth.”
No it’s not. If x is time in years, the annual growth factor = (exp(0.0045*(x+1))/exp(0.0045*x) = exp(0.0045). It just so happens that you’re lucky that this evaluates to a growth percentage of 0.45% if you round this to two significant digits, but you can’t in general say that the factor in the exponent is the growth rate.
The word “rate” alone means little, by the way, you’ll need to define what it’s a rate of. For instance, here we seem to have confusion between “rate of change” and “rate of growth”. You appear to have been using “rate of growth” with which you appear to mean a growth factor, expressed as a percentage.
On the other hand, a “rate of change” is often understood to mean the change per time unit, or the derivative of a function. The derivative of your function is 0.00019035*exp(0.0045*x), which is a monotonously increasing function, so the rate of change increases over time.
To me, it’s quite clear that Chris is talking about a rate of change, not a rate of growth, in which case his remark about an increasing rate of change was entirely correct. Your ridiculing of Chris’ math skills means you either didn’t know about this common use of the word “rate”, or you chose to not give him the benefit of the doubt that he just might have been using it in a way consistent with his own words. In both cases, an apology might not be a bad idea.
“In this case, the RATE (e.g. ppmv/year, %/year etc) is the ratio of the amount which CO2 increased over e.g. 2005 to the mean level of CO2 in 2005 (NOT the level in 1970).”
You appear to describe a ratio between a concentration change and a mean concentration for a year. This is not a growth rate, in either meaning of the word, and would not have a unit of ppmv/year, but a unit of ppmv/ppmv (in other words, dimensionless). You’ll need to divide the concentration change by the period of change to get a growth rate with a unit of ppmv/year.
(pedantic mode off)
And Chris, don’t give up, you’re not alone.
Er, no.
(pedantic mode on)
Consider that something grows, proportional with time as well with quantity. In such a simple model growth takes place exponentially as a function of the time.
This can also be formulated as dy = a y dt, so y’ = a y and y(t) = y(0) e at.
That’s why the curve is also called a GROWTH CURVE.
The exponential function grows faster than each polynomial (in x), and we can prove that in the Limit as x goes to infinity (x^a/e^x) = 0
The curve y = 0.0423exp(0.0045x) R^0.9951 is actually an exponential line of best fit to each and every NOAA global mean monthly pCO2 (ppmv) from January 1980 to June 2008! i.e. N = 342. Each and every month is expressed to 7 significant figures e.g. 2008.458, and each and every pCO2 (ppmv) is expressed to 5 significant figures e.g. 385.68
(pedantic mode off)
Congratulations, I never never ever seen anyone so comprehensively disprove their own thesis.
Essentially you are saying that a light bulb (or the earth) can only take so much energy before it reaches equilibrium, put in more energy and it >disappears<
You’ve single handedly broken the law of conservation of energy!
Perhaps you are thinking of a rechargeeable battery? But look – when it’s fully charged it can’t store any more energy and – wait for it – it gets hot!
Have you actually tried this light bulb experiment? there are a number of possibilities:
1) Your IR reflectors cannot be perfect and there are other routes for energy to escape (e.g. conduction) – as the temperature rises more heat WILL escape.
2) The filament’s resistance rises with temperature, it will accept less energy per unit time unless you keep ramping up the voltage.
3) The filament will get hotter until it melts.
But assume you /can/ pump more energy into you box, one way. Basically the contents will get hotter and hotter and it will get harder and harder to pump more energy in.
Eventually you open the box, and with a large bang the contained plasma (for that is what the superheated contents now are) explodes outwards releasing ALL the energy you put in.
But seriously, if you really belive what you posted, you are sad.
Gordon,
no, you still don’t get it.
The value “1” does *not* come from multiplying of 0.03 with 38 (which makes no sense whatsoever). Spencer’s use of “1 part-per-100000 in 5 years” is just a another way of saying 2 ppm/year which is the current mean increase per year (http://www.esrl.noaa.gov/gmd/ccgg/trends/index.html#global). Why he uses this weird terminology instead of just ppm/year, I don’t know, but it sounds like rhetorics to make it seem small.
Why don’t you try and listen to the people who spends precious time trying to explain your flaws in claiming “~97% of the CO2 in the atmosphere is from natural sources”?
I’ll give it another try. The number 3% does not represent the *level* of atmospheric CO2 attributed to human emissions, but rather the percentage of *emissions* of CO2. And since nature absorbs about as much as it emits, it doesn’t contribute to any increase of the CO2 level. The human emissions, on the other hand, just adds to the total amount.
So to summarize the different percentage values; about 3% of the yearly *emissions* are attributed to human activity. About 100% of the yearly *increase of atmospheric* is from these “human” emissions (since nature absorbs about as much as it emits). And about 36% of the total amount of atmospheric CO2 is “human” (the increase from pre-industrial levels of ~280 ppm to today’s 380 ppm being from “human” emissions).
It’s also interesting to note how you, after failing to admit you were wrong, insits on “putting the calculator away”.
Finally, I’d be careful not to talk about errors made by Hansen and at the same time put so much faith in Spencer & Christy, as if they had not done major errors (http://www.realclimate.org/index.php/archives/2005/11/more-satellite-stuff).
Steve, you’re not being pedantic, you’re being imprecise.
“Consider that something grows, proportional with time as well with quantity. In such a simple model growth takes place exponentially as a function of the time.”
This sentence translates to a different differential equation:
y'(t) = a*t*y(t)
Note the proportionality with time. The solution of this is *not* the exponential function. I know what you meant to say, but you didn’t write it that way.
I know about the exponential function, thank you very much. The dispute is not about the exponential function anyway, and its limit behavior is not relevant to the discussion. Nobody denied that this exponential function might be a good fit for the data. The dispute was about usage of “rate of change” and “rate of growth”, and their relation to derivatives and growth factors. This confusion is what you ridiculed Chris’ math skills over. Your last post doesn’t address this at all though, and in fact continues to be imprecise.
“exponential line”
There is no such thing. “Line” has a rather precise meaning in a mathematical context. Lines are straight, not “exponential”.
But I suppose this post won’t get you to admit even the possibility that you might have been wrong to ridicule Chris over this issue. It’ll probably just help escalate the pedantry even further. I hope I’m wrong though.
“You had been one of the few I could disagree with in a constructive fashion, but now you too have succumbed to the viciousness that seems to infest this blog.”
What it means they have nothing to say, and respond in the only way they have left, abuse. In other words Chris, (not that you’re here any more), you won. They just don’t have the guts to admit it.
“Thus, if the incoming flux rate exceeds the outgoing flux rate, then the level builds up until the outgoing flux rate is once again equal to the incoming flux rate, and equilibrium is re-established.”
Magic happens!
The fact that, at night, a cubic meter of air is heated by OLR is definitive proof that radiative equilibrium does not exist in that region.
As the emissivity of green leaves exceeds that of H2O & CO2 vapor by 3 orders of magnitude at STP the region cannot radiatively heat the ground even if slightly hotter and can do so only via conduction.
Couple of (minor) points.
(1) Due to the lack of an adequate number of global staions and and insufficient number of measurements per year at the existing suite of stations, NOAA will not ‘certify’ a global mean CO2 value prior to January 1980. This is why Mauna Loa data was used as a proxy for the global means prior to 1980. So, sorry Chris – data prior to 1980 (IPCC or not) is not adequate to measure global mean trends according to NOAA.
(2) Let’s look at theis question of ‘rates’ (no matter how loosely or tightly ‘defined’). NOAA have issued an update with very slight amendments to their global monthly mean CO2 levels since the data file I last downloaded. A linear fit to the period January 1980 to June 2008 is: y = 1.6239x – 2879.0745 R^2 = 0.9809 (n=342). The mean CO2 level over this period was 359.4518 ppmv so the average linear growth ‘rate’ was 1.6239*100/359.4518 = 0.4518%/year if you will. An exponential fit to the same period is: y = 0.0445exp(0.004500x) R^2 = 0.9829 (n=342) so the exponential (instantaneous) growth rate was 0.4500%/year i.e. closely similr to what I posted before.
(3) Now Chris asserts that the the ‘rate of increase’ has increased markedly. So let us look at (say) the last 10 years from July 1997 to June 2008. A linear fit to the period July 1997 to June 2008 is: y = 2.0012x – 3634.6 R^2 = 0.9408 n=132. The mean CO2 level over this period was 373.8594 ppmv so the average linear growth ‘rate’ was 2.0012*100/373.8594 = 0.5353%/year if you will. An exponential fit to the same period is: y = 0.0083exp(0.005300x) R^2 = 0.9406 n=132 so the exponential (instantaneous) growth rate was 0.5300%/year.
(4) So in all fairness it certainly looks as though, in comparison to the average rate of growth in CO2 over the the last of the last 28.5 years from January 1980 to June 2008, for the last ten years July 1997 – June 2008 be it measured ‘linearly’ as an average or exponentially as instantaneous, CO2 has indeed risen at a faster (higher) rate over the last 10 years of that period.
(5) Oh damn! I’m so sorry. I completely forgot. It is all a complete and utter muck up. Perceived trends over the last 10 years don’t count and can’t be used, can they! Their use is of course completely invalid on correctly extrapolated and appropriately trended global warming timescales. Silly, silly me. Please forget everything I wrote above. It is unreservedly withdrawn.
“Silly, silly me. Please forget everything I wrote above. It is unreservedly withdrawn.”
Noted, and minuted.
Steve, still comparing apples and oranges, I see. Let me try one last time to show why you never should ridicule anyone’s math skills again. I apologize to everybody else reading this, but it appears I’m really going to have to spell this out:
linear fit:
y1(t) = 1.6239*t – 2879.0745 ppmv.
y1′(t) = 1.6239 ppvm/year
So according to this model, CO2 levels increase at a constant rate of 1.6239 ppmv/year.
exponential fit:
y2(t) = 0.0445*exp(0.0045*t)
y2′(t) = 0.0045*0.0445*exp(0.0045*t)
According to this model, CO2 levels increase at a growing rate, from 1.4830 ppmv/year in 1980 to 1.6821 ppmv/year in 2008.
You could express these rates into percentages relative to the quantity of the current year if you want, in the following way:
p(t)=(y'(t)/y(t))*100%
Linear fit:
p1(t)=(1.6239/(1.6239*t – 2879.0745))*100% = 100%/(t – 1772.938) which decreases from 0.4829%/year in 1980 to 0.4254%/year in 2008.
Exponential fit:
p2(t) = 0.45%/year, which is constant (as expected for exponential growth).
You can also express the rates as percentages relative to the average of the function over a time period. The average of a function over a period (t_start, t_end) is determined by integrating the function over this interval and dividing by the length of the interval.
P(t) = 100%*y'(t)/avg
avg = (Y(2008)-Y(1980))/(2008-1980), where Y(t) is the primitive function of y(t).
For the linear model, we get:
P1(t) = 0.4524%/year, which is a constant, as expected.
For the exponential model, we get:
P2(t) = 5.701*10^-5*exp(0.0045*t), which increases from 0.4222% in 1980 to 0.4789% in 2008.
By now it should be clear what you did wrong in your last post: you compared a percentage relative to the current quantity for the exponential model with a percentage relative to the average quantity for the linear model.
It should now also be clear that the exponential function grows at a constant rate if by “rate” you mean “growth percentage relative to the quantity in the current year”, but at an increasing rate if by “rate” you mean “change in quantity per year” or even “percentage of change relative to the average quantity”. Both views are valid, and both views are useful. What you should not do, however, is confuse them as you did.
So, let me ask you, Steve: did you attack Chris’ math skills because you didn’t understand that Chris and you could have been referring to different types of “rates” so that his remarks could be interpreted as perfectly consistent? Or did you know, but chose to deliberately misunderstand him so you could ridicule? If the former, you may want to apologize and refrain from commenting on people’s perceived lack of math skills in the future, because yours have been found lacking. If the latter, that of course would make you a troll.
But it’s all just Socratic Irony, right?
Anton said…”I’ll give it another try. The number 3% does not represent the *level* of atmospheric CO2 attributed to human emissions…”
Sorry, Anton…you’re dead wrong. I just had it confirmed in an email from the DOE and they forwarded me to the IPCC source. Here’s the DOE link:
http://www.eia.doe.gov/bookshelf/brochures/greenhouse/Chapter1.htm
and if you read the fine print at the bottom of Figure 2, it will lead you to the IPCC source. The IPCC even states that the amount of anthropogenic CO2 is very small compared to the natural sources.
About realclimate…you show me anyone there with any real expertise in atmospheric physics. The place is full of mathematicians, computer programers and geologists who can’t use proxy data correctly. I was kind to Hansen because I don’t favour ad hominum attacks. Still, he’s an astrophysicist with no formal training in atmospheric physics. He’s been seriously wrong in the past about warming and I personally feel that has something to do with his lack of understanding of the atmosphere at a deep level.
I saw a debate involving Gavin Schmidt where he artfully dodged debating Richard Lindzen. He made a lame speech to the effect that he would not be debating the science and that anyone wanting the facts should contact realclimate. I also read the paper by Glassman, in which he revealed Schmidt’s lack of basics in physics.
Gordon: are you serious? Somebody points out that 3% of CO2 *emissions* are anthropogenic, not 3% of current CO2 *levels*, and you counter by referring to a figure that shows CO2 *fluxes*? A figure that *confirms* that 3% of CO2 *emissions* are anthropogenic? That makes no statement on how much of current CO2 *levels* are anthropogenic?
The figure you refer to even shows there’s a positive net flux into the atmosphere of 4 billion metric tons of CO2 per year, which is less than the human emissions of 7.2. That shows it’s theoretically possible to eliminate the positive net flux by lowering human emissions. This makes it even more puzzling why you chose this figure to support your position.
The figure also shows the current CO2 content of the atmosphere at 760 billion tons. With a net flux 4 billion tons of CO2/year, that amounts to 0.53% per year relative to the current quantity. That doesn’t sound like much, but assuming this net flux stays constant long enough, in 50 years that’s an increase of over 25% compared to now. That’s a significant increase within only a couple of human generations.
Note that this is entirely consistent with Roy Spencer’s number of 1 additional molecule CO2 per 100,000 molecules of air per 5 years: from a baseline of 38/100,000, that evaluates to an increase of 1/38/5*100% = 0.53% per year compared to now as well. It’s just that Roy Spencer presents his numbers in such a way that they *sound* ridiculously small. He wants people to forget we’re talking about billions of tons of CO2 here, but even his numbers can’t deny that the overall levels of CO2 will rise by 25% in just 50 years if they continue to rise at this pace.
Still a big “if”, of course, which leaves enough room for a debate, and there is still some uncertainty about the consequences of such an increase in CO2 levels. But muddling the current numbers isn’t going to help the discussion one bit.
Oh, and Gordon, you may want to put a little less emphasis on people’s credentials and more on the content of their arguments. Such authoritarian reasoning makes you look like a pseudo-skeptic. Besides, I’ve found such reasoning often leads to disqualifying yourself from the debate as well.
Gordon,
this is amazing. You’re still confusing emissions with level, and point me to a figure that very clearly shows what we are trying to tell you: Nature releases a lot of carbon every year, but it also re-absorbs equal amounts (actually, currently even more). Anthropogenic emissions on the other hand are not balanced, which results in atmospheric CO2 level net growth.
From the figure:
– Natural emissions/year: 210.2 gigatonnes carbon.
– Anthropogenic emissions/year: 8.8 gigatonnes carbon.
– Total: 219 gigatonnes carbon.
So according to their numbers, human emissions are around 4% of the total carbon emissions.
BUT, this is not the same as the *increase*, nor the *level* of CO2 in the atmosphere.
After having included the absorbed amounts, the numbers are:
– Nature net result: -2.2 gigatonnes carbon/year.
– Human net result: +6.2 gigatonnes carbon/year.
– Total net result: +4 gigatonnes added to the atmosphere every year. (which means +2 ppmv CO2)
Please, it’s really not that hard.
“Please, it’s really not that hard.”
As a matter of fact it is much too hard for Climate Science.
Fluences are by definition vector quantities, your arithmetic employed in balance equations is daft.
Look at the Mauna Loa or AIRS daily and nightly data points. The variance is 20ppm at 3km or on the order of 100Gtons for DAILY fluences.
That variance is anticorrelated with a biogenic source.
Spencer’s F-Test of the 13C/12C fraction of the CO2 variance for the seasonal signal and long-term trend shows that they have the same origin:
the oceanic partial pressure.
You boys have nothing on Gordon or Spencer, quit posing.
Beowulff said…”It’s just that Roy Spencer presents his numbers in such a way that they *sound* ridiculously small. He wants people to forget we’re talking about billions of tons of CO2 here, but even his numbers can’t deny that the overall levels of CO2 will rise by 25% in just 50 years if they continue to rise at this pace”.
The numbers ‘are’ ridiculously small compared to the overall CO2 produced naturally. The IPCC even admits that, claiming that anthropogenic CO2 is only a fraction of the natural CO2. I realize that a billion tons sounds like a big number, but compared to the total amount of CO2 released from the land and the ocean, and the gigantic volume of the atmosphere, it’s peanuts.
However, forget the math for a minute and visualize the 1 CO2 molecule contributed by humans and surrounded by 100,000 molecules of air. Seriously, what heat effect is that molecule going to have? If there is a heat effect, it is being done by the 97% of the CO2 molecules contributed by natural means, and that is peanuts.
If you read Spencer further, and you should, rather than reading the mathematician and computer modeler Gavin Schmidt, he claims that greenhouse warming is far more complicated than a molecule of CO2 absorbing and re-emitting heat. It has to do with water vapour transport systems that carry heat high into the atmosphere, where it cools and releases precipitation as rain or snow. Please note the cooling after condensation.
Furthermore, Spencer and Christy have observed such phenomenon directly via satellite but the AGW crowd doesn’t want to hear it. Thay have witnessed a cooling effect by clouds.
The system is so complex it is not clearly understood, yet modelers like Schmidt think they can apply differential equations to it and make predictions. Lindzen, Christy and Spencer, who are bona fide atmospheric physicists, are trying to tell people like Schmidt that they have the signs wrong on their feedbacks.
Instead of Schmidt having the humility of a serious scientists, who would want to know what they are getting at, he derides them. He arrogantly implied that Lindzen, a professor at MIT with over 40 years experience in the atmosphere was ‘old school’ and that his computer driven rhetoric is ready for textbooks. The guy comes across to me as an egomaniac, not a serious scientist. A serious scientist would go to those guys and say, “OK…can you show me where you think my model is wrong”.
So what if the CO2 rises 50% in the next 50 years? It has risen significantly since 1995 and the warming trend has been essentially flat. Not only that, the May 2008 study figured there would be no warming till 2016 because of the Atlantic and Pacific Oscillations, then it would magically start warming again.
Man…I’ve had that kind of pseudo-science up to here. As far as I’m concerned, studies like that are well-placed people justifying their tenure and their funding. They haven’t got a clue as to what is happening.
Anton said “So according to their numbers, human emissions are around 4% of the total carbon emissions. BUT, this is not the same as the *increase*, nor the *level* of CO2 in the atmosphere”.
Anton…I think you are confusing a few things. For one, the current level has been clearly stated by the IPCC as about 380 ppmv, or as Spencer puts it, 38 molecules of CO2 per 100,000 molecules of air.
The IPCC claims it was about 280 ppmv in the pre Industrial era, a figure that leaves me skeptical due to the proxy data from which it was derived. In fact all CO2 levels beyond about 1950 are artificially derived. We’re basing the 280 ppmv on polar ice cores. Is it not reasonable to assume the density may have altered by the time the CO2 drifted to the poles? And, as Jaworowski claims, ice at great depth is under tremendous pressure. That, and water being introduced along the way affects the carbon isotopes, and so does the heating from the extraction drill.
The IPCC claims that all of the CO2 increase from 280 ppmv to 380 ppmv is anthropogenically derived, simply because there’s no other explanation. Do you call extracting carbon isotopes from ice in polar regions, and infering a carbon density, a reasonable explanation for anthropogenic changes in CO2 density?
The point to note is that the CO2 density was 280 ppmv then and it is 380 ppmv now. The IPCC is alleging that NOW the balance of emissions of CO2 are 97/3 natural to anthropogenic. Yet, they are claiming that the 100 ppmv increase over about 300 years came totally from anthropogenic sources.
Never mind the distant past for now, since 1990, only 3% of all CO2 emissions were anthropogenic. Half of that 3% is unaccounted for. Is there any reason to assume that remaining 1.5% has changed drastically over the years? 300 years ago, the IPCC maintains 0% of all CO2 emissions was anthropogenic. Between then and now, that 0% has increased to 1.5% of all CO2 emissions, yet the atmosphere has gained 100 ppmv of CO2. Do you not question that increase at all? I sure do. I’d be willing to bet the density of CO2 300 years ago was closer to what it is now than to 280 ppmv.
I understand the exponential nature of the added CO2, it will keep increasing each year. But only 50% of it goes into the atmosphere according to the IPCC. Over time, it gets reabsorbed as well and the absorption of all CO2 is done at a rate of 97.5%. So, they want us to believe, that although the ratio of natural to anthropogenic emissions today are 97/3, that somehow over the past 300 years, only anthropogenic CO2 built up in the atmosphere.
I’ve heard the fancy theories about how emissions of CO2 have been calculated over time, and if that was true, they’d be able to put a gas meter in the air and measure that amount of CO2. But they can’t because they still can’t account for where the CO2 goes. NASA gave up on it because they can’t account for 40% of the anthropogenic emissions.
I’m not talking about how much anthropogenic CO2 is in the atmosphere, I’m talking about what we contribute. Out of that 380 ppmv, we are contributing 1 molecule every 5 years. When that 98.5% of CO2 is reabsorbed, do you think the anthropogenic molecules are labelled, “please don’t reabsorb”?
You can use your calculator all you want, my brain tells me there is something really wrong with the theory. I don’t care if CO2 doubles, or trebles, the history of warming over the past 60 years has shown us that the warming response is minimal. Furthermore, we’ve had about a 33% increase in CO2, according to the IPCC, since 1998, and the warming trend has been flat.
I have always felt that we should cut back on all emissions and I’m all in favour of doing that over time. I don’t see one bit of evidence for doing it now and in a hurry.
“Fluences are by definition vector quantities…”
No, they’re not. Besides, we were talking about flux, not fluence anyway. After this, I fail to see the need to indulge you in your attempt at changing the topic.
Oops, link didn’t work. Fluence: http://en.wikipedia.org/wiki/Fluence
Gordon said:
“However, forget the math for a minute and visualize the 1 CO2 molecule contributed by humans and surrounded by 100,000 molecules of air. Seriously, what heat effect is that molecule going to have?”
See, that’s where you go wrong, and that’s precisely what Spencer hopes for. You want people to work with their gut feelings, and people’s guts are notoriously bad at working with numbers. In fact, clearly many people’s *brains* even have difficulty. So by all means, put your calculator away if you want, but don’t expect other people to do that too.
First mistake: it’s not surrounded by 100,000 molecules of air, you’re conveniently leaving out the 38 molecules of CO2 that are already there. It still doesn’t sound like much, but you’re off by a factor 39 already.
Second, there is not just one molecule of CO2, or 39 for that matter (nor are there only 100,000 of air molecules). 4 billion metric tons of extra CO2 per year works out to about 5.47*10^37 additional molecules of CO2 per year. Can you visualize that? Can you imagine that many molecules having at least *some* effect?
It’s not that difficult to see why Spencer preferred to use the 1 in 100,000 per five years number over the 5.47*10^37 molecules per year number. They’re both true in a way, but they both create totally different intuitive responses. That’s why you shouldn’t just trust your intuition in these matters.
You keep focusing on how small the human emissions are compared to the natural emissions. Don’t you understand that this doesn’t matter? It doesn’t matter where the actual molecules of CO2 came from, nature doesn’t care, and radiation doesn’t care. It only matters that there is a *net gain* in the *total amount* of CO2. And since the human contribution is larger than this net gain, it’s likely that without the human contribution, there would not be a positive net gain, and CO2 levels would likely not be rising. It’s really that simple. And remember, all this can be learned from the figure *you* selected to support your position.
Really, if you can’t grasp this simple, basic concept, what point is discussing anything more complicated with you, like thermodynamics and non-linear dynamics? It’s almost like you don’t *want* to understand it.
I’m starting to understand why Chris gave up trying to educate people on this blog on basic science and math… I can only hope that more neutral readers will learn something from all this.
I’m off for vacation, with little to no internet access, giving my SIWOTI syndrome a little rest. So I won’t be back at this thread. Have fun.
Beowulff…I realize you’re off for a holiday but I’ll reply anyway.
The thing you don’t seem to comprehend is how vast the atmosphere is. The human contribution of CO2 is less than 3% of ALL CO2, and ALL CO2 is about 3/100ths of a percent of the atmosphere. That’s the trouble with numbers, you get a large figure and can’t put it in perspective because your brain can’t allow for that.
You’re right about the difference in intuitive responses. Neither my brain nor yours can visualize 5.47*10^37 molecules but they can begin to visualize 1 molecule in relation to 100,000. That’s why I asked you to put your calculator away because you can’t begin to comprehend the numbers anyway.
5.47*10^37 molecules is not a lot in the overall scheme of the atmosphere and I find it really doubtful such a density of CO2 per 100,000 molecules of air could make that much of a difference.
No one’s brain can figure out what is happening to that CO2 or how it is affecting the atmosphere. In fact, no one’s brain can know for sure what the density of CO2 was in the pre Industrial era. Here’s proof of that from an expert on ice core proxy data:
http://www.warwickhughes.com/icecore/zjmar07.pdf
I would think Spencer’s thinking behind the 1 molecule in 100,000 per 5 years comes from his incredulity at the stubbornness of computer modelers who ignore his satellite data. It’s so damned obvious, based on the data, that no net warming has taken place for 10 years and that the tropical tropospheric hot spot has not developed.
The public is mislead by computer model nonsense and someone needs to put things in perspective for them. I think the 1 in 100,000 analogy per 5 years tells it like it is, and explains why no warming has taken place over the past decade.
“No, they’re not. Besides, we were talking about flux, not fluence anyway.”
Pimple on Grendel’s behind: flux, fluxion, fluence, all synonymous to Webster, D. Who cares what Connelley thinks?
Ok, you don’t do vector calculus, few of us do (I did good just to get points for the set up of multivariate problems with Stewart’s equations).
We will take scalar math if you appropriately tag your little CO2 molecules, following Suess, and show us that any change in the atmospheric 13C/12C fraction is due to your–fluxes.
This is exactly what Spencer did and found the seasonal sinusoid (which Keeling thought biogenic) riding on top of the Mauna Loa trend had the same variance, a straight line, as the trend in terms of this ratio using an F-Test.
The trend is the combination of all–fluxes. The seasonal–flux–could be a partition, e.g., a biogenic–flux–drowning out the remaining components of erosion, etc., but the evidence refutes that notion.