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Post by jimcripwell on Jan 29, 2011 20:49:07 GMT
glc writes "Would you like to provide an example of what you're talking about. In what way are the "warmaholics" using physics which contradicts the 2nd law of thermodynamics. "
The warmaholics give the physics of how doubling CO2 is supposed to cause global surface temperatures to rise. This is a three stage process (see the IPCC TAR Chapter 6)
1. Estimate the change in radiative forcing. (3.7 Wm-2)
2. Estimate how much this change in forcing produces the no-feedback sensitivity. (1.2 C)
3. Estimate the feedbacks. (times 3 to 5)
None of these steps follow the scientific method. There is no observed data. The radiative forcing has not been measured, and probably cannot be measured. The no-feedback sensitivity has not been measured, and almost certainly can never be measured. The feedbacks have not been measured, and probably cannot be measured.
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Tomas Milancovic has shown that the process of estimating no-feedback sensitivity cannot be done. G&T has shown that the whole process violates the second law of thermodynamics.
There is simply no science in the way the warmaholics state that adding CO2 to the atmosphere causes surface temperatures to rise. A far more likely explanation of how this happens is that GHGs change the lapse rate and the height of the TOA.
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Post by magellan on Jan 29, 2011 21:25:45 GMT
glc writes "Would you like to provide an example of what you're talking about. In what way are the "warmaholics" using physics which contradicts the 2nd law of thermodynamics. " The warmaholics give the physics of how doubling CO2 is supposed to cause global surface temperatures to rise. This is a three stage process (see the IPCC TAR Chapter 6) 1. Estimate the change in radiative forcing. (3.7 Wm-2) 2. Estimate how much this change in forcing produces the no-feedback sensitivity. (1.2 C) 3. Estimate the feedbacks. (times 3 to 5) None of these steps follow the scientific method. There is no observed data. The radiative forcing has not been measured, and probably cannot be measured. The no-feedback sensitivity has not been measured, and almost certainly can never be measured. The feedbacks have not been measured, and probably cannot be measured. ' Tomas Milancovic has shown that the process of estimating no-feedback sensitivity cannot be done. G&T has shown that the whole process violates the second law of thermodynamics. There is simply no science in the way the warmaholics state that adding CO2 to the atmosphere causes surface temperatures to rise. A far more likely explanation of how this happens is that GHGs change the lapse rate and the height of the TOA. touche' and not to mention all the failed "fingerprints" of AGW which warmers would just assume fade away. I stand by my axiom:  |
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Post by steve on Jan 29, 2011 21:48:10 GMT
glc writes "The main arguments in the G&T paper are nonsense" You are misreading G&T. They are not talking about how AGW works. They are talking about the physics that the warmaholics claim is how AGW works. Two entirely different things. It is not that AGW is contrary to the second law of thermodynamics; it is not. It is that the physics that the warmaholics claim is the way that adding CO2 to the atmosphere causes global temperatures to rise, is against the second law of thermodynamics. Jim, they say in 3.9.4: Now since "AGW" and the physics in climate models are essentially part of the same thing, I don't quite follow what you mean. Having reread just some of the relevant sections, you may be right that they do not directly use the "AGW is disproven by the 2nd law" argument". But if so it is an easy mistake to make as it appears to be a mistake that most of the readers of the article have made - including astromet, glc, Roy Spencer and many of Roy's "followers" who *still* hold that AGW is disproven by the 2nd law. When G&T talk about the 2nd law they appear to refer to the simplified descriptions of the greenhouse effect that break the law. But even there they get a bit confused because they complain about Rahmsforf referring to net radiation transfer: They are confused because they say Rahmsdorf's reference to the 2nd law is wrong, when it is the people Rahmsdorf is quoting that are referencing the 2nd Law. This goes back to my point about the paper being unnecessarily confusing. I have a second observation which relates to the section I quoted. G&T refer to "net energy flow" as being an "obscure notion". And that "the relevant quantity is 'the net heat flow'". Now any physicist worth his salt has no problem with net energy flow as energy is the more fundamental physical quantity - it cannot be destroyed/created etc. Heat, though, is a manifestation of energy and, when you look more deeply into it, is a bit of a fuzzy subject. At the atomic and molecular level the concept of heat is not relevant, and more complete statement of the 2nd law would not refer to heat - rather to entropy. |
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Post by glc on Jan 30, 2011 11:07:44 GMT
glc writes "Would you like to provide an example of what you're talking about. In what way are the "warmaholics" using physics which contradicts the 2nd law of thermodynamics. " The warmaholics give the physics of how doubling CO2 is supposed to cause global surface temperatures to rise. This is a three stage process (see the IPCC TAR Chapter 6) 1. Estimate the change in radiative forcing. (3.7 Wm-2) 2. Estimate how much this change in forcing produces the no-feedback sensitivity. (1.2 C) 3. Estimate the feedbacks. (times 3 to 5) None of these steps follow the scientific method. There is no observed data. The radiative forcing has not been measured, and probably cannot be measured. The no-feedback sensitivity has not been measured, and almost certainly can never be measured. The feedbacks have not been measured, and probably cannot be measured. ' Tomas Milancovic has shown that the process of estimating no-feedback sensitivity cannot be done. G&T has shown that the whole process violates the second law of thermodynamics. There is simply no science in the way the warmaholics state that adding CO2 to the atmosphere causes surface temperatures to rise. A far more likely explanation of how this happens is that GHGs change the lapse rate and the height of the TOA. Oh dear. Jim, do you not perhaps think that it is your understanding of the "warmaholics" case that is at fault. You say A far more likely explanation of how this happens is that GHGs change the lapse rate and the height of the TOA.Quite. If you go back over my posts you'll find that I've made this very point time and time again. As CO2 accumulates in the atmosphere the average emission height increases so that emission is at higher and COLDER levels. Because it's COLDER the energy emitted is reduced (S-B Law). How much is it reduced for a doubling of CO2? It's 3.7 w/m2. The estimate of radiative forcing is entirely consistent with the 'changes' at TOA. PLEASE Note that the change in forcing is at TOA NOT at the surface which is what appears to confuse your friend Tomas Milancovic. On this, you say: Tomas Milancovic has shown that the process of estimating no-feedback sensitivity cannot be done. No he hasn't. TM has assumed the radiation forcing is at the surface and has cobbled together some equations which produces a circular 'solution', i.e. forcing -> temp change -> forcing His argument appears to be that the forcing is needed as input to calculate the forcing. It's not. His equations are not valid. They do not model what is happening in the atmosphere. G&T has shown that the whole process violates the second law of thermodynamics.How have they? Show me how they have done this? You continually jump on every crackpot anti-AGW theory because you hope it's right. You don't even understand what they're trying to prove - as you've readily admitted. All leading atmospheric physicists including those that are sceptical of 'catastrophic' AGW accept that the 3.7 w/m2 (~1 deg C) forcing is a pretty robust figure. We know enough lapse rates an the opacity of the atmosphere to have a high degree of confidence in the no-feedback figure. Richard Lindzen and several others have included this number in their published work. Jack Barrett has written countless papers and books on IR spectroscopy. He has been arguing the sensitivity issue with the IPCC for almost 20 years, but he fully acknowledges that the earth's greenhouse effect exists and that increasing CO2 will further enhance it. The only issue for debate is feedback. If feedbacks are low (or negative) then temperature increases are likely to go unnoticed and will probably be 'lost' in the natural variability of the climate. If feedbacks are strongly positive - well - that's another matter. |
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Post by glc on Jan 30, 2011 11:28:04 GMT
touche' and not to mention all the failed "fingerprints" of AGW which warmers
Again you're confusing "warmers" with lukewarmers and the general principle of the greenhouse effect. The greenhouse effect exists- that comes under "s**t we know". Assuming no feedbacks doubling CO2 will increase global temperatures by ~1 deg C. That's also "s**t we know". The magnitude (and sign*) of feedbacks can probably be categorised as "s**t we don't know".
* Though, I doubt very much that feedbacks are negative.
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Post by magellan on Jan 30, 2011 16:00:45 GMT
touche' and not to mention all the failed "fingerprints" of AGW which warmers Again you're confusing "warmers" with lukewarmers and the general principle of the greenhouse effect. The greenhouse effect exists- that comes under "s**t we know". Assuming no feedbacks doubling CO2 will increase global temperatures by ~1 deg C. That's also "s**t we know". The magnitude (and sign*) of feedbacks can probably be categorised as "s**t we don't know". * Though, I doubt very much that feedbacks are negative. Name the pillars of AGW that have been upheld by observations and "basic physics". It isn't basic physics, because if it were, there wouldn't be such huge variations in the climate models. Model-dependence of the CO2 threshold for melting the hard Snowball Earth* Though, I doubt very much that feedbacks are negative. Observations don't support your doubt. |
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Post by glc on Jan 30, 2011 21:47:35 GMT
Observations don't support your doubt.
If feedbacks are negative (i.e. sensitivity is very low) then it's difficult to see how the earth entered (and came out) of the ice ages.
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Post by sigurdur on Jan 30, 2011 22:29:49 GMT
Observations don't support your doubt.If feedbacks are negative (i.e. sensitivity is very low) then it's difficult to see how the earth entered (and came out) of the ice ages. GLC: The earth entering and exiting glacial conditions with low sensitivity show what we don't know. There is still one heck of a lot about climate science that is devoid of knowledge. The little bit that we do know and understand is presented as if that is all that needs to be known. Far from it. |
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Post by glc on Jan 31, 2011 12:17:52 GMT
GLC:
The earth entering and exiting glacial conditions with low sensitivity show what we don't know.
I rather think it shows that feedbacks (over the longer term, at least) are positive.
I'm always amused by the confidence some posters have in their assertions. However, when faced with an 'inconvenient fact' they invariably conjure up the possibility of mysterious forces which 'we' are unable to explain or understand.
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ZL4DH
Level 3 Rank
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Post by ZL4DH on Jan 31, 2011 12:40:34 GMT
GLC:
The earth entering and exiting glacial conditions with low sensitivity show what we don't know.I rather think it shows that feedbacks (over the longer term, at least) are positive. I'm always amused by the confidence some posters have in their assertions. However, when faced with an 'inconvenient fact' they invariably conjure up the possibility of mysterious forces which 'we' are unable to explain or understand. You mean like the sun. |
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Post by steve on Jan 31, 2011 12:48:04 GMT
GLC:
The earth entering and exiting glacial conditions with low sensitivity show what we don't know.I rather think it shows that feedbacks (over the longer term, at least) are positive. I'm always amused by the confidence some posters have in their assertions. However, when faced with an 'inconvenient fact' they invariably conjure up the possibility of mysterious forces which 'we' are unable to explain or understand. You mean like the sun. If this is a serious rather than a flippant comment, you are saying that the Milankovitch cycles (basically small wobbles in earth's access and orbit) drive the sun to be more, or less, active. ie. the wobbles don't cause the ice age cycles by themselves. The wobbles cause the sun to be more or less active and that is what causes the cycles. I think you were being flippant. But glc's question deserves a serious answer. |
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ZL4DH
Level 3 Rank
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Post by ZL4DH on Jan 31, 2011 13:29:43 GMT
If this is a serious rather than a flippant comment, you are saying that the Milankovitch cycles (basically small wobbles in earth's access and orbit) drive the sun to be more, or less, active. ie. the wobbles don't cause the ice age cycles by themselves. The wobbles cause the sun to be more or less active and that is what causes the cycles. I think you were being flippant. But glc's question deserves a serious answer. I don't see any questions in glc's blog just 3 statements, one of them was a flippant remark about mystical inconvenient things in climate science which i thought deserved a flippant remark and now i'm convinced it did. |
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Post by steve on Jan 31, 2011 15:37:03 GMT
Fair enough. But the first statement wasn't flippant and is very important. Restated as a question:
If feedbacks are negative (i.e. sensitivity is very low) then how did the earth enter (and come out of) the ice ages?
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Post by magellan on Jan 31, 2011 17:16:04 GMT
Fair enough. But the first statement wasn't flippant and is very important. Restated as a question: If feedbacks are negative (i.e. sensitivity is very low) then how did the earth enter (and come out of) the ice ages? If positive feedbacks are dominant, then how did the earth get out of an ice age and not become a frozen wasteland ad infinium? When the ice did melt, why didn't it continue until the oceans boiled away? It works both ways and why negative feedbacks lead to stability rather than out of control runaway climate. That is the natural order of things. It is only in post normal science that assumes climate is dominated by positive feedback. P.S. the use of "very low" is funny. |
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Post by steve on Jan 31, 2011 17:59:42 GMT
Fair enough. But the first statement wasn't flippant and is very important. Restated as a question: If feedbacks are negative (i.e. sensitivity is very low) then how did the earth enter (and come out of) the ice ages? If positive feedbacks are dominant, then how did the earth get out of an ice age and not become a frozen wasteland ad infinium? When the ice did melt, why didn't it continue until the oceans boiled away? It works both ways and why negative feedbacks lead to stability rather than out of control runaway climate. That is the natural order of things. It is only in post normal science that assumes climate is dominated by positive feedback. P.S. the use of "very low" is funny. The use of "dominant" is funny too. So feedbacks are high during changes in the cycle and low at the ends? Well maybe, but it is not a given! The last glacial maximum ended roughly 20000 years ago, so the ice albedo feedback managed to induce a warming of roughly 0.05C per 100 years (lower than I said above). So the climate *is* quite stable. But not so stable that the slight wobbles of the Milankovitch effect eventually turn the tide. But it isn't completely stable and it is easy to calculate that the changes due to adding CO2 are far more rapid than the average rate of ice gain or loss even leaving aside the feedbacks in addition to the albedo feedbacks that can be inferred. PS. Maybe we should take this onto arthur's thread and leave space for Jim to explain his understanding of G&T's 2nd law statements, and for astromet to show off with some integration over spherical coordinates. |
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