when you calculate out the hydrological cycle winners and losers , invasion of rangelands by C3 woodies, and major effects of increased frost sensitivity with higher CO2 – get back to us.

Don’t give us some piddly greenhouse trial result in ideal circumstances, or a try-on that yield increases in the field have nothing to with improved agronomy or genetics

In any case ocean sinks may be shutting down –

http://www.sciencedaily.com/releases/2009/01/090102101045.htm

* The Canadell et al PNAS paper and their associated Global Carbon Project are a good source of data but not of growth rates; the fact of ever increasing world food production (FAO)does not support their claim of a declining capacity of the terrestrial sink.

I think he is a bit militant in his views that his statement is the only thing you should ever say in regards to the greenhouse effect. But, strictly speaking, I suppose he is correct that statements such as “re-radiates” and “traps radiation” are sort of shorthands that can lead to confusion. At any rate, his is really a pedagogical argument more than a scientific one. (In fact, it is interesting to contrast with G&T because I think that in the examples that they give, they are really making essentially pedagogical objections to the explanation of the greenhouse effect but then they use these to essentially argue that the science is actually wrong. If they simply stuck to improving pedagogy, like this fellow, they might actually be useful rather than destructive.)

Joel Shore…thanks for reply. I can’t reply at this time but I will respond in a few days.

Thanks, Gordon. I look forward to it. In the meantime, I will try to respond briefly to the points that you bring up.

The fundamental problem I have with your mathematical analysis is that it ignores the problem of radiative heat flow between two bodies. You are describing a black body transfer which applies normally to a continuous spectrum of radiation at higher temperatures than those found in the atmophere.

I am not sure what you mean in your first sentence. In fact, my analysis is precisely an analysis of radiative heat flow between the bodies, the bodies in question being blackbodies as this makes the problem easily tractable. Also, I am not sure what you mean by your second sentence. The radiation spectrum for a blackbody radiator can be defined for a body at any temperature. In fact, in astrophysics there is the so-called “3-deg background radiation” which is at only ~3 K above absolute zero.

Also, your physical description using two concentric spheres around a sphere at constant temperature does not describe the atmophere-surface interaction for me.

Well, I am not trying to give a complete physical description of the atmospheric greenhouse effect. What I am trying to do is respond to the following argument from G&T that you summarized thusly (actually arguably better than they summarized it themselves):

G&T, real physicists, claim that kind of back-warming is not possible … A third reason is the interpretation of the laws of thermodynamics by Clausius. He claimed that a body cooler than a body that warms it cannot warm the warming body (through back radiation) to a temperature higher than the warming body was in the first place. The atmosphere is cooler than the surface, and according to Clausius, it cannot warm the surface more than the surface temperature that warmed the atmosphere.

…

This is basic thermodynamics!! Certain pseudo-climate scientists (ie. don’t have actual degrees in atmospheric physics), like Hansen, have finagled formulas to get a ‘net energy balance’ that contravenes the laws of thermodynamics, according to G&T. They have invented the equivalent of a refrigerator that cools without a compressor, and a motor to drive it. Negative heat flow is not possible without an external energy source to drive it.

Hence, to show that this argument is incorrect, it is useful to show that there is a much simpler problem, so simple that we can solve it exactly, that illustrates exactly what G&T claim cannot occur: Namely, the presence of an object Shell B (analogous to the IR-absorbing atmosphere) that “back-radiates” onto an object Shell A (analogous to the earth) causes Shell A to be at a higher temperature than it would be in the absence of Shell B. Hence, this shows that what G&T claim constitutes a violation of the 2nd Law of Thermodynamics does not in fact constitute such a violation at all.

Furthermore, this simple problem illustrates the hole in their logic: They seem to assume that if Shell B causes Shell A to be at a higher temperature than it would be in the absence of Shell B, then the net flow of heat must be from Shell B (which is colder) to Shell A (which is warmer), which would indeed be a violation of the Second Law. However, what I have shown is that the net flow is still from Shell A to Shell B. Shell A is warmer with Shell B there than without it there not because there is a NET flow of heat from Shell B to Shell A but rather because Shell B is able to radiate back to Shell A ANY of the heat that Shell A radiates whatsoever (because when Shel B is not there then, of course, it doesn’t).

I would prefer to see an analysis using known amounts of CO2 and it’s ability to absorb and retransmit IR. In the NASA article I linked to for SJT, they admit that energy budgets are not known precisely for the atmosphere. From what I have read, only a theoretical analysis of the energy exchange between surface and atmosphere have been attempted. Even your thought experiment is highly theoretical. True blackbody radiators are a theoretical concept and no one knows where the low temperature atmosphere-surface interface falls into that theory.

I’m not going to try to explain the entire CO2 atmospheric greenhouse effect to you from first principles. I myself haven’t read back through all of the original papers…This is old settled science that even skeptical scientists like Richard Lindzen agree with (i.e., that doubling CO2 produces a radiative forcing of somewhere around 3.7 to 4.0 W/m^2). If you want to learn more about it, I suggest the link that I gave you before to the history by Spencer Weart at the American Institute of Physics which can provide you with background, history and references: http://www.aip.org/history/climate/co2.htm

And, while it may be true that ideal blackbody radiators are a theoretical concept, the fact is that many materials approach pretty close to this ideal. Furthermore, it is irrelevant for the basic point of discussion (which was whether the basic picture of an IR-absorbing atmosphere which is colder than the earth nonetheless warming the earth relative to what its temperature would be in the absence of that atmosphere constitutes a violation of the 2nd Law of Thermodynamics).

It’s one thing for you to give your thought experiment to first year physics student and quite another for them to go out and prove it. Then again, that’s how paradigms are cemented into the heads of undergraduates. They either swallow the bs or they fail. Later, as graduate students, they wont get far unless they are ready to accept what the profs say. Even with a doctorate, they are usually obliged to buy into the paradigm of the faculty and university they will be employed at.

You have a pretty cynical…and, in my experience, inaccurate…view of how things work in our colleges and universities, at least in the physical sciences. Students disagree with their professors all the time…And sometimes the students even end up being correct. And, faculty often vociferously disagree with each other.

However, in this case, the problem that I have presented is simple enough that I am rather doubtful that there is a major error in it. And, of course, unlike G&T’s conclusions, it is perfectly in line with over a hundred years of understanding of the issue by thousands of scientists.

I would prefer to see an analysis using known amounts of CO2 and it’s ability to absorb and retransmit IR. In the NASA article I linked to for SJT, they admit that energy budgets are not known precisely for the atmosphere. From what I have read, only a theoretical analysis of the energy exchange between surface and atmosphere have been attempted. Even your thought experiment is highly theoretical. True blackbody radiators are a theoretical concept and no one knows where the low temperature atmosphere-surface interface falls into that theory.

It’s one thing for you to give your thought experiment to first year physics student and quite another for them to go out and prove it. Then again, that’s how paradigms are cemented into the heads of undergraduates. They either swallow the bs or they fail. Later, as graduate students, they wont get far unless they are ready to accept what the profs say. Even with a doctorate, they are usually obliged to buy into the paradigm of the faculty and university they will be employed at.

I’ve told you that there is a radiation physics problem simple enough to be given to first year physics students that demonstrates what G&T claim is impossible from the laws of thermodynamics. I haven’t specifically given you the problem because it takes a while to explain…but I will do so when I have more time in a subsequent post.

Okay, here it is:

Consider a spherical body at a constant absolute temperature T. Now surround that spherical body by a concentric spherical shell A of very slightly larger radius and then surround that by a concentric spherical shell B of very slightly larger radius than A; surrounding this all is empty space (i.e., at an absolute temperature of 0). Assume that all three bodies are perfect blackbodies. [The assumptions such as the objects being perfect blackbodies and the radii of the shells being only slightly larger than the radius of the sphere should not be necessary to show the basic effect...But they are necessary to make the problem tractable enough to be a problem one could give to first-year physics students.]

(a) Derive the steady-state temperature T_A of Shell A when Shell B is not present.

(b) Derive the steady-state temperature T_A of Shell A and T_B of Shell B when Shell B is present.

(c) What is the net radiant heat flow (W/m^2) between Shell A and Shell B?

The answers are

(a) T_A = T / 2^(1/4), which is ~0.841 T.

(b) T_A = T * (2/ 3)^(1/4), which is ~0.903 T and T_B = T / 3^(1/4), which is ~0.760 T.

(c) (1/3)*sigma*T^4 from A to B.

So, what we have is a situation where the addition of the Shell B has caused the temperature of Shell A to be higher than it would be in the absence of Shell B (~0.903 T instead of ~0.841 T), yet Shell B is at a lower temperature than Shell A. This is the sort of situation that G&T claim would violate the Second Law of Thermodynamics, i.e., that we have warmed an object (Shell A) to a warmer temperature than it would have an the absence of the “back-radiation” from a cooler object (Shell B).

Of course, as you can see, the net heat flow is from Shell A to Shell B and thus the 2nd law is not in fact violated, just as is true of the earth / atmosphere case where the net flow of heat is from the earth to the atmosphere and yet the presence of the IR-absorbing atmosphere still results in the earth being warmer.

Personally, I think that it would be pretty cool as a first-year physics student to be able to demonstrate that two PhD theoretical physicists are wrong!

The thing that impresses me most about him, however, is that he actually did the experiments on greenhouse conditions using his own car and a box he set up using different kinds of glass. Are you familiar with that method? It’s called the scientific method and the beauty of it is that you can reproduce it yourself and see if you get the same results. I’ll take Gerlich’s words for it, but if you doubt him, why don’t you replicate his experiement and convince yourself that real greenhouses work due to the lack of convective heat flow and NOT radiative heat flow.

I meant to comment on this. Not everything in G&T is incorrect and their claim that real greenhouses work by a different mechanism (i.e., they trap heat in a different way) than the atmospheric greenhouse effect is correct but is so well-known that it is noted in many, if not most, elementary discussions of the atmospheric greenhouse effect. For example, see the section “Real greenhouses” on this Wikipedia page: http://en.wikipedia.org/wiki/Greenhouse_effect

So, while Gerlich may have impressed you with his implementation of the scientific method to devise an experiment, he has used it to demonstrate something that is already well-known and well-accepted in the literature and even explained in many popular explanations of the greenhouse effect.

a simple summing up of the relevant flows in that diagram from NASA will show that more heat is flowing from the earth to the atmosphere than vice versa. So, there is no violation the laws of thermodynamics and yet as a result of these flows, the earth is still warmer than it would be in the absence of a heat-trapping atmosphere.

By the way, if it seems counterintuitive that the atmosphere could be keeping the earth warmer than it would be otherwise when more heat is flowing from the earth to the atmosphere than vice versa, it might help to think of it this way: In the absence of a heat-trapping atmosphere, none of the radiation that the earth emits would come back to it, i.e., it would be, roughly speaking, “giving the same amount away but getting nothing back”. However, with a heat trapping atmosphere, it is now getting some of what it gives away back…not all of it of course, but this is still going to keep it considerably warmer than the alternative of not getting any of the heat back.

You counter with your own opinions and theories, as if they hold any value, and you criticize experts who work in the field of physics.

Well, you are dismissing experts in a similar way, only with some important differences:

(1) You don’t actually have the necessary scientific background to judge their work.

(2) The scientists who you are dismissing (Jim Hansen, for example) are ones with a huge publication record in the field and who have won important awards and honors from their scientific peers. While the scientists who you are promoting (G&T) have no publication record that I know of in the field.

(3) You are promoting the views of these scientists over the views of organizations such as the IPCC and the U.S. NAS (National Academy of Sciences) and the analogous bodies in the other G8+5 nations. Despite your views regarding the IPCC, its reports are in fact considered to be the definitive summaries of the current state of the science in the field and they are cited in almost every paper published in the peer-reviewed journals in the field. And, the NAS was created specifically to advise the federal government to offer the best scientific summaries and advice to policymakers and the public.

You claim your attacks on G&T were not ad hom. Claiming they don’t know anything about the laws of thermodynamics, without supplying proof, is an ad hom attack.

I’ve told you that there is a radiation physics problem simple enough to be given to first year physics students that demonstrates what G&T claim is impossible from the laws of thermodynamics. I haven’t specifically given you the problem because it takes a while to explain…but I will do so when I have more time in a subsequent post.

You can’t even be bothered to inform yourelf as to their qualifications and you use that lame argument about peer review (i.e. where were they published).

Peer review was introduced to keep scammers out of science, now it is being used to censor skeptics. When people like G&T reach a level of Ph.D. and they are working in cutting edge science, that’s good enough for me.

Well, it may be good enough for you but it is not for me. A PhD does not mean one is incompable of being ignorant or deceitful. And, for that matter, Jim Hansen and Gavin Schmidt and the leading authors of the IPCC reports have PhDs too and yet you seem to have no difficulty dismissing their work (sometimes by making lame excuses that their PhDs aren’t in fields you think are as relevant, based on what criterion of relevancy I do not know).

Dr. Ralf Tscheuschner collaborates with Dr. Gerlich, so I would assume he has an equivalent standing. He is a researcher in Applied Solid State Physics. His expertise seems to be in atomic physics with research in superconductivity and the Hall Effect. I have communicated with him and he has talked about superconductivity studies. I don’t think anyone would be researching superconductivity without being an expert in heat theory.

Do you really expect these qualifications to impress me? Although it was not the main focus of my work in my pre-industrial days, I too have worked some in superconductivity. In fact, I published a paper in this field in Physical Review Letters, the most prestigious physics journal in the U.S. (and arguably the world): http://prola.aps.org/abstract/PRL/v62/i26/p3089_1 More of my work was in statistical physics, which…among other things… forms the theoretical underpinning of thermodyanics. And, on the more practical side, in my industrial job, I have also done more engineering-type heat flow calculations. So, I have spanned the whole range from the very theoretical to the practical on that subject.

You completely misunderstand what G&T are trying to say. It is impossible for more heat to flow from the Earth to the atmosphere than vice-versa.

Actually, you have that backwards. What they are claiming is that it is impossible for more heat to flow from the (upper) atmosphere (which is colder) to the earth (which is warmer). And, while they are correct on this point (in regards to net heat flow), a simple summing up of the relevant flows in that diagram from NASA will show that more heat is flowing from the earth to the atmosphere than vice versa. So, there is no violation the laws of thermodynamics and yet as a result of these flows, the earth is still warmer than it would be in the absence of a heat-trapping atmosphere.

As far as your argument about slowing down heat radiated from the surface, how is that accomplished? IR travels at the speed of light. It is absorbed and transmitted that fast. How do you slow that down?

Yes, the radiation travels at the speed of light but there is still the issue of the quantity of radiative energy per unit time. One measures these flows in Watts, which is Joules (a unit of energy) per second. By “slowing down”, I meant the rate of heat flow in Watts is slower. I.e., I was thinking in terms of a given number of Joules of heat exchange now taking a longer amount of time. However, if this confuses you, it is perfectly equivalent to think of it as, in a fixed period of time, a smaller amount of heat being transferred.

When you consider the density of the IR reflected from the surface, how can a gas as rare as CO2 possibly impede it?

It may be rare but there is also a lot of atmosphere. In fact, some “skeptics” like to argue (wrongly, but for somewhat subtler reasons) that adding more CO2 doesn’t make a difference because all of the absorption bands are already saturated. (And, to be fair, a half century ago, I believe this argument was even in the scientific mainstream. If you want to read more about the history of all this, go here: http://www.aip.org/history/climate/co2.htm ) So, could you guys at least decide whether you think there is not enough CO2 or whether there is already so much that an additional amount doesn’t matter!?!