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Comments 87401 to 87450:

87401. Donald Lewis at 17:08 PM on 27 April 2011
       Christy Crock #4: Do the observations match the models?
       Hey anyone, and maybe Dikran Marsupial in particular. (BP and Gilles, you can skip this.) I am confused by how "variability in model prediction" is being analyzed in this thread in order to characterize ensembles of climate models. From my point of view, one certainly expects to get variability in the behavior of a particular dynamical system if one changes initial conditions or the values of time-varying parameters. One also gets variability of outcome if one builds stochastic uncertainty into the dynamics but keeps initial conditions fixed and doesn't alter the time dependence of parameters. (And clearly different models can produce different outcomes.) There are several reasons why the same model can produce different outputs on different runs. My question concerns the source of variability within the individual models discussed in this thread. Is it due to uncertainty in initial conditions, uncertainty in time-dependence of parameters, an assumption that the dynamics are stochastic, numerical instability or chaos in the model, or some combination of these sources of variability? Anyway, I believe "ensemble mean" is a wonderful, ancient, and useful concept, it is just that for climate models I don't have the background to identify the sources of run ensemble variability either within or between models. (This is just a question about the mainstream models, not about the actual climate variability as it unfolds before us.)
87402. Kevin C at 16:02 PM on 27 April 2011
       CO2 is plant food? If only it were so simple
       I knew nothing about the C3 and C4 pathways until recently when I was trying to understand why the C13/C12 isotope ratios for fossil carbon where different than for atmospheric carbon (thus allowing the identification of fossil carbon on the atmosphere). The reason is that while C12 and C13 are chemically identical, but their different masses mean that they diffuse across membranes at different rates. Different diffusion steps mean that the two pathways fix different amounts of C13. The C4 pathway is more efficient, but only evolved recently.
87403. Craig Cogger at 15:42 PM on 27 April 2011
       CO2 is plant food? If only it were so simple
       This post is a balanced and understandable treatment of a very complex topic. Well done!
87404. trunkmonkey at 15:25 PM on 27 April 2011
       Models are unreliable
       342. All that happened after we mucked it up. Look, we are in uncharted territory. I know perfectly well that the millions of tons of CO2 we have dumped are producing some warming. Did you read 339? What I am saying is that hindcasting may be misleading. You may recall that I am haunted by a feeling that we are missing a piece to the puzzle, whether it be before our noses and we are overlooking it, or something beyond our current understanding. I fully realize that I, who have repeatedely invoked Occam, am ignoring him here. But nothing we have comes close to explaining the three things in 339.
87405. Dan Moutal at 14:59 PM on 27 April 2011
       CO2 is plant food? If only it were so simple
       And just to make things more complicated it is being reported that CO2 fertilization is killing koalas because CO2 fertilized plants put more of their energy into structure. Eucalyptus leaves become harder for present day koalas to digest because they are more fibrous. This is probably not restricted to eucalyptus and might indeed affect some of the plants we eat, or at least affect more animals than just the Koala.
87406. RW1 at 14:40 PM on 27 April 2011
       Clouds provide negative feedback
       Sphaerica (RE: 152), "It matters what types of clouds form, where they form, and when they form. More clouds in northern latitudes in winter will not nave a net cooling effect. High clouds made of ice crystals that are transparent to visible light will not have a net cooling effect. Clouds that build beyond a certain critical depth will not have a net cooling effect. OK, explain specifically how all the various cloud types will respond in a way that results in a net warming effect on the next few watts at the surface and specifically why all different cloud types don't respond this way to the original 239 W/m^2 incident on the surface from the Sun. "It's more complicated than your simplistic logic makes it sound." I know the balance is complicated. It doesn't change the fundamentals. Besides, Dessler doesn't get into different types of clouds in his analysis.
87407. scaddenp at 14:25 PM on 27 April 2011
       Models are unreliable
       No truckmonkey, we know that isnt true. The isotope ratios for fossil fuel produced CO2 is different from that produced by carbon cycle feedbacks. If you look at the isotopes in CO2 from ice core bubbles, the increased CO2 during warming is from carbon cycle. If you look at isotope ratio in current atmosphere, you see increase is due to fossil fuel. At the moment, the carbon sinks are cleaning up about half our emissions. Over longer time, this will reverse.
87408. RW1 at 14:24 PM on 27 April 2011
       Clouds provide negative feedback
       Sphaerica (RE: 15), "your logic that if the effect of clouds is a net negative in the current climate, then a changed climate must have more clouds with the same net negative effect, only more so, is simplistic." No, not really. My point is there is really no physical or logical reason why the net cloud feedback would suddenly switch from negative (cooling) to positive (warming) on the next few watts incident on the surface, especially to cause a net warming effect so much greater than the response of the system to the original 98+% (239 W/m^2) incident on the surface from the Sun.
87409. RW1 at 14:02 PM on 27 April 2011
       Clouds provide negative feedback
       muoncounter (RE: 151), "Oh, that makes it all perfectly clear. A mechanism of warming, 'not in dispute,' doesn't conflict with net negative feedback? Do you have any evidence to support this astounding statement?" I'm not sure I understand your objection. The net effect of clouds, globally averaged (night and day combined), is to cool. The fact that clouds are much better at trapping outgoing surface emitted radiation than the clear sky, which makes their net effect at night to retain more energy than the clear sky, would only be significant it was more than the energy the clouds reflected away during the day.
87410. Marcus at 13:48 PM on 27 April 2011
       Cosmic ray contribution to global warming negligible
       Yes Muon, funny how the "skeptics" play up the so-called "uncertainty" surrounding Anthropogenic Warming, yet are very quick to promote any other potential source of warming-regardless of how *weak* the foundation for it is. Anyone would think they were trying to "kill the CO2/climate connection".
87411. Bob Lacatena at 13:45 PM on 27 April 2011
       Clouds provide negative feedback
       150, RW1, What else does Dessler say in his paper? Let me give you a hint... your logic that if the effect of clouds is a net negative in the current climate, then a changed climate must have more clouds with the same net negative effect, only more so, is simplistic. It matters what types of clouds form, where they form, and when they form. More clouds in northern latitudes in winter will not nave a net cooling effect. High clouds made of ice crystals that are transparent to visible light will not have a net cooling effect. Clouds that build beyond a certain critical depth will not have a net cooling effect. It's more complicated than your simplistic logic makes it sound.
87412. trunkmonkey at 13:38 PM on 27 April 2011
       Models are unreliable
       Sorry about the double post. Don't know how to retract it. All I did was refresh. 340. I am saying that until we mucked it up the rise in temperature produced the rise in CO2.
       Moderator Response: [DB] Refreshing after posting will result in a double (triple, quadruple, etc) posting. You are not the first, nor will you be the last.
87413. muoncounter at 13:12 PM on 27 April 2011
       Clouds provide negative feedback
       RW1#149: "net effect of clouds at night is to warm (or slow heat loss)... Again, this is not in dispute, nor does it conflict with net negative feedback for clouds." Oh, that makes it all perfectly clear. A mechanism of warming, 'not in dispute,' doesn't conflict with net negative feedback? Do you have any evidence to support this astounding statement? Or does your model simply require that you assume a net negative feedback and thus do not need to bother with any evidence?
87414. RW1 at 13:06 PM on 27 April 2011
       Clouds provide negative feedback
       Sphaerica (RE: 148), "You keep saying there's a net negative cloud effect, but (1) you don't prove it," I've provided much evidence and logic for net negative cloud feedback. Even Dessler says in his paper the net effect of clouds is to cool by 20 W/m^2. "(2) as several people have pointed out, the important factor isn't the net current effect, it's the net change as a result of warming." I'm aware of this, but I'm not the one making the claim that the net effect of clouds is suddenly going to switch from cooling to warming on the next few watts incident on the surface.
87415. muoncounter at 12:59 PM on 27 April 2011
       Cosmic ray contribution to global warming negligible
       HR#33: "This obscure paper " Comments on the Rao paper are here on the prior Its cosmic rays thread. Not so obscure. "Those that seem to want to kill the CGR/climate connection are as ideologically motivated as the worst sceptics" Wow, how did you get there? Who is trying to kill the connection - if so, why did CLOUD even get built? What are the 462 citations you claimed in #27? How does that in any way suggest anyone is trying to kill the connection? Please do not make such accusations without any trace of substantiation. No, the problem with the GCR/climate connection is that no one can substantiate it and that 'skeptics' are desperately trying to cling to it. Do you think they are ideologically motivated?
87416. HumanityRules at 12:45 PM on 27 April 2011
       Cosmic ray contribution to global warming negligible
       28 Philippe Chantreau As far as I'm aware the necessary experiments have yet to be performed to answer your criticisms although there is plenty of speculation on mechanisms and even some supporting evidence (such as much of Harrison's work). Applied science is never based on one piece of evidence and an idea is never dismissed because one piece of the puzzle still eludes us. I guess you fully support the continued investigation of this problem? "I'm not so sure that 462 citations in 14 years is that remarkable." That's funny! 29 muoncounter This obscure paper from the Indian Academy of Science Journal seems to suggest the impact on global temperature is very different to the paper Ari has presented. Very few scientists have bothered to quantify the impact of CGR on global temperatures, I'm not sure that Svensmark has even bothered to do this. I think my position on this science is much like the rest of climate science. Uncertainty in the science rules, which suggests further investigation before firm conclusions can be made. Those that seem to want to kill the CGR/climate connection are as ideologically motivated as the worst sceptics. And the IPCC position on this issue can only have the effect of strangling research on this subject.
87417. RW1 at 12:45 PM on 27 April 2011
       Clouds provide negative feedback
       muoncounter (RE: 47), "I don't know where you live, but in my neck of the woods, nights don't get cool when there's high humidity (which is almost always) or high clouds. But here's how an actual weatherperson puts it: Clouds are regions of a high density of saturated air, (which form cloud droplets). Clouds (especially low thick clouds) have a high ability to absorb and re-emit longwave radiation. Thus, on cloudy nights much less longwave radiation is able to escape to space. Holding in heat at night is a fingerprint of the enhanced greenhouse effect. So your thesis that clouds will always be negative feedbacks doesn't hold water." Yes, net effect of clouds at night is to warm (or slow heat loss). This is because clouds are better at 'trapping' outgoing surface energy than the clear sky is. Again, this is not in dispute, nor does it conflict with net negative feedback for clouds. Globally averaged data automatically includes the effects of night and day.
87418. muoncounter at 12:43 PM on 27 April 2011
       Antarctica is gaining ice
       RyanS#78: "seasonally the ice expanse at the poles swings wildy. In winter ocean ice is a multiple 5-10 times what it is in summer, ... there is and always has been very much melting at the poles" If by 'poles,' you're including the Arctic, then you are: a). off topic b). making an unsubstantiated claim c). incorrect. Arctic ice extent did not always swing wildly; there are a number of Arctic ice threads with plenty of actual data to examine. If it's credibility you seek, point to some numbers.
87419. RyanStarr at 12:25 PM on 27 April 2011
       Antarctica is gaining ice
       CBD I'm not exactly sure what you're getting at in the first paragraph. Are you eluding to the fact that ice melts or doesn't melt and for all temperatures below 0 the ice will be frozen? That's true but we're not dealing with a smooth climate, seasonally the ice expanse at the poles swings wildy. In winter ocean ice is a multiple 5-10 times what it is in summer, as a ball park range. So there is and always has been very much melting at the poles and our concern is the mean figures over time.
87420. RyanStarr at 12:14 PM on 27 April 2011
       Muller Misinformation #1: confusing Mike's trick with hide the decline
       I asked what was a non sequitur nil point and pointed out that it was difficult getting a straight answer to straight questions from you guys. The question being do you agree with John Cook's quote. The mod snipped the whole post. He/She leaves your post unedited telling me that I act like a school teacher. Is this how we discuss science?
       Moderator Response:

       [DB] In order to be fair, comments with content in violation of the Comments Policy yet containing substantive points germane to the topic of the thread will typically have the egregious portions snipped. Repeated violations of the policy will result in the comment being deleted en toto.
       
       Per my response to you above, the criticism mentioned was of the technique, not the person utilizing the technique.  Just to be clear.
       
       I did not infer from Les' comment about teaching that there was intent to demean. Les? Want to elaborate on that point?

87421. Bob Lacatena at 11:59 AM on 27 April 2011
       CO2 effect is saturated
       149, RW1,

       This amount represents the theoretical maximum that can be emitted to space from the clear sky atmosphere, which is less than 169 W/m^2 emitted by the atmosphere depicted by the Trenberth diagram.

       Wrong. You are discounting energy from other sources (such as thermals, latent heat, energy absorbed directly from the sun, and energy transferred from clouds to the "clear sky," as you call it). The input into the "clear sky" is 78 from the sun, 17 from thermals, 80 from latent heat, an unknown fraction of 396 from the surface, and an unknown amount transferred from clouds. You cannot separate the clouds from the clear sky with that diagram. You can't figure out how much energy the "clear sky" has to emit. You can't do it, except in the single, explicit case in the diagram where outgoing LWR is separated between clouds and "clear sky." You cannot back yourself into the numbers you'd like to see. You can't do it. You can't do it. (And even if you could, it has no bearing whatsoever on the topic of the post, i.e. whether the CO₂ effect is saturated.)
87422. Bob Lacatena at 11:47 AM on 27 April 2011
       Clouds provide negative feedback
       146, RW1,

       However, the vast majority of the Earth is not snow or ice covered, which is consistent with net negative feedback for clouds, globally.

       So you say, but you offer no (substantive) support that actually proves this. You keep saying there's a net negative cloud effect, but (1) you don't prove it, and (2) as several people have pointed out, the important factor isn't the net current effect, it's the net change as a result of warming. Similarly, your logic is only so much "thought experiment" with no substantive calculations. It's easy to say things like "strong cooling effect" without backing such statements with actual numbers.
87423. muoncounter at 11:46 AM on 27 April 2011
       Cosmic ray contribution to global warming negligible
       HR#31: "an issue for any work trying to find correlations between clouds and anything, including all those papers that refute Svensmark's work." Why? If there's no correlation between GCR flux and any observable weather effect, doesn't Svensmark's hypothesis refute itself? If there's been nothing of value from the CLOUD experiment in the last 5 years, doesn't Svensmark's hypothesis refute itself? And of course, if there's no physical basis for it, doesn't it refute itself?
87424. muoncounter at 11:43 AM on 27 April 2011
       Clouds provide negative feedback
       RW1#146: "the vast majority of the Earth is not snow or ice covered, which is consistent with net negative feedback for clouds" I don't know where you live, but in my neck of the woods, nights don't get cool when there's high humidity (which is almost always) or high clouds. But here's how an actual weatherperson puts it: Clouds are regions of a high density of saturated air, (which form cloud droplets). Clouds (especially low thick clouds) have a high ability to absorb and re-emit longwave radiation. Thus, on cloudy nights much less longwave radiation is able to escape to space. Holding in heat at night is a fingerprint of the enhanced greenhouse effect. So your thesis that clouds will always be negative feedbacks doesn't hold water.
87425. HumanityRules at 11:27 AM on 27 April 2011
       Cosmic ray contribution to global warming negligible
       "There's also a possibility that the whole hypothesis rests on artifacts in cloud data." This is going to be an issue for any work trying to find correlations between clouds and anything, including all those papers that refute Svensmark's work. The sad fact is cloud data is terrible for this sort of work.
87426. RW1 at 10:44 AM on 27 April 2011
       Clouds provide negative feedback
       muoncounter (RE: 145), "Documentary evidence that cloud feedback is positive, courtesy of the good folks at the North Pole webcam site: Spring conditions can be cloudy at the North Pole. Clouds are produced when the North Pole experiences Spring warming and the beginning of Summer melting. Water is evaporated from the melting snow surface, forming the fog and low clouds that are seen in Spring/Summer pictures from the North Pole, such as the one on the right from June 2002. In the left image, from 5/1/02 19:06 UTC, the surface is covered by fog and low clouds. Radiation energy is trapped near the surface and thus the temperatures have increased to a very warm 27 F. -- emphasis added" It's not disputed that the cloud feedback is positive in areas that are permanently snow and ice covered, such as the North Pole. This is because the albedo of clouds is roughly the same as snow and ice, so the net effect of clouds is to warm by 'trapping' additional surface emitted energy. However, the vast majority of the Earth is not snow or ice covered, which is consistent with net negative feedback for clouds, globally. Also, when ice or snow melts from warming (CO2 induced or otherwise), the primary mechanisms that drive negative cloud feedback reassert themselves - specifically the latent heat of evaporation, which has a strong cooling effect on the surface, and the clouds above become more reflective than the surface, which also has a strong cooling effect.
87427. RW1 at 10:01 AM on 27 April 2011
       CO2 effect is saturated
       Sphaerica (RE: 137) "First, you can't just assume that because 1/3 of the sky is clear then that the clear sky absorbs 1/3 of the radiation." I'm not claiming the clear sky absorbs 1/3rd of the radiation. I'm saying that 1/3rd of the average surface radiation is emitted to the clear sky. This amount represents the theoretical maximum that can be emitted to space from the clear sky atmosphere, which is less than 169 W/m^2 emitted by the atmosphere depicted by the Trenberth diagram. "The ability to absorb long wave radiation is dramatically different between clear sky and clouds (clouds probably absorb substantially more, being made up of a powerful greenhouse gas, but I've never really seen any numbers on this)." I'm well aware of this. I don't see how this contradicts anything I've said. Using Trenberth's numbers, the cloudy sky absorbs 89% of the LW surface radiation emitted to it. The clear sky only absorbs 69% of the surface radiation emitted to it. "Clouds and the radiative properties of the surface are also not evenly distributed over the globe, either in space or in time. Everything else is not homogeneous." I never claimed it was. Relative to the energy balance, the averages (cloudy vs. clear sky) are what matter. "Second, you cannot ignore the non-radiative components (thermals and the release of latent heat)." I haven't. I'm well aware of them. "Third, and most importantly, you cannot ignore a major element which is not included in the diagram, which is the transfer of heat between "clear sky" and clouds. What happens when a cloud dissipates? Does the heat vanish? Is it forced to instantly radiate up to space? Does it fall to the ground with the rain?" No heat vanishes. It's either is radiated out to space, radiated down to the surface or returned to the surface in kinetic form mainly via precipitation. "Hint: When a cloud absorbs LW radiation, it is capable of transferring that heat to the surrounding and pervading atmosphere (remember, a cloud isn't a solid object, it coexists in space with the O2/N2 of the atmosphere). So it doesn't really matter which absorbs the radiation." What's your point? That the clear sky absorbs LW too? "The atmosphere (consisting of "clear sky" and clouds) absorbs the radiation, and the two cannot be separated into distinct components re this diagram." The average clear vs. cloudiness comes from the ISCCP data - not the Trenberth diagram. If, as you claim, the diagram is not depicting a 40 W/m^2 "window" through the clear sky and a 30 W/m^2 "window" through the cloudy sky with a total of 169 emitted by whole atmosphere, show me the power in = power calculations that demonstrate it. I have done so. "This diagram is not a GCM. It's just a diagram intended to help communicate the earth's energy budget to the casual viewer, and nothing more. You cannot read as much into it as you are attempting." I never claimed the diagram is a GCM. It's an energy budget diagram. With the exception of the ISCCP data on clouds, everything it taken directly from the diagram.
87428. Daniel Bailey at 10:00 AM on 27 April 2011
       CO2 Reductions Will Not Cool the Planet? We Know
       @ Don9000 Bravo, sir. You have coined a phrase: Climate Appeasement. With that in mind, let us all dwell on the words of Martin Niemöller: First they came for the Jews and I did not speak out because I was not a Jew. Then they came for the Communists and I did not speak out because I was not a Communist. Then they came for the trade unionists and I did not speak out because I was not a trade unionist. Then they came for me and there was no one left to speak out for me. Now is the time to speak out...while yet there is time to make a difference. The Yooper
87429. JMurphy at 09:59 AM on 27 April 2011
       Lindzen Illusion #1: We Should Have Seen More Warming
       That comment from Argus is a fantastic resource as a conglomerate of many so-called skeptical beliefs and complaints. It can be boiled down to sham shock, dismissal, belittling, incomprehension, misunderstanding, selective idolisation, hypocrisy, wishful-thinking, double-standards, a martyrdom-complex, naivety, and an unawareness of the absurdity of most of the claims made.
87430. Don9000 at 09:48 AM on 27 April 2011
       CO2 Reductions Will Not Cool the Planet? We Know
       Tony Abbott's statement, which I have copied below, needs to be understood from the other side's perspective: "So this is a government which is proposing to put at risk our manufacturing industry, to penalise struggling families, to make a tough situation worse for millions of households right around Australia. And for what? To make not a scrap of difference to the environment any time in the next 1000 years." Those of us who grasp that AGW is real and a serious threat easily see the flaws in this line of reasoning. The one sentence rebuttal might read something like this: "Tony, the flaw in your argument is that you fail to realize that failing to act now and going forward to reduce CO2 emissions will result in global temperature increases and climate changes that will end up costing Australian industries and struggling families much much more a generation or two down the line." This line of reasoning is second nature to many of us posting comments to this site, but it is clearly not one easily grasped by most members of the general public. For them, Abbott's statement appears to make quite good sense. As long as this holds true, we have a very perilous path ahead of us. The key flaw in Abbott's reasoning is not that he is denying global warming is happening. Instead, it is one that conservatives (in the general sense of preferring the status quo or old understanding of things rather than the new) by their nature are often guilty of: he has failed to take the additional steps in the reasoning process that are necessary to understand the need for action. Here in the U.S. I would venture to say that many opponents of taking significant action against AGW fall into Abbott's camp. A good analogy is found in the way the British government responded to Nazi aggression during the lead up to the Second World War. Over and over again, under Baldwin and Chamberlain, the British government chose to appease Hitler, rather than confront him. Appeasement had the immediate benefit of putting off the terribly unpleasant idea that much stronger action, as advocated by people like Winston Churchill, might be required. In a similar fashion, Abbott and his ilk are appeasers. Like Baldwin and Chamberlain, they are selective or biased in their use of facts, fail to follow the evidence to the logical conclusions, and yet the path they advocate offers up a far more rosy future to the populace. Whereas Baldwin and Chamberlain appeased Hitler and the Nazis, Abbott and others like him appease those of us who want to continue burning fossil fuels without any limits in the belief that doing so is not a threat. Fundamentally, as the British establishment knew full well, the alternative to appeasement in the 1930s inevitably boiled down to war. My point is that a similar situation exists today. Those of us who believe massive action is required starting right now are effectively in the position of Churchill in the lead-up to WWII. We are, in effect, calling for war. Against this, Abbott's line of reasoning is a siren call for "peace in our time" that many people find quite attractive: like Baldwin and Chamberlain, he and his ilk are betting that the consequences of their form of appeasement will either not be fully apparent till they are long gone, or will be less bad than the Churchills of our time are predicting. Our task is to convince the quavering or ignorant masses that our way is the right way forward. To do this, I think we must begin to draw attention to the craven and flawed nature of politicians like Abbott.
87431. KR at 08:41 AM on 27 April 2011
       CO2 effect is saturated
       Berényi - Also note that in sea level pressure, in the saturated CO2 bands, absorption distance is ~10 meters, not zero, and this distance increases with altitude and reduced CO2 concentration. For unsaturated wavelengths this absorption distance is much further. Given that, I don't believe a simplistic thermal conductivity measure can incorporate radiative effects. Seriously, BP - you're obviously very intelligent. But a lot of very intelligent people have been working in this field for >100 years... if you think you have (once again - I recall about a dozen of these, in UHI, OHC, etc., that did not pan out) found an issue that all the bright people have missed, you might be correct. But it's far more likely that you've missed something.
87432. logicman at 08:28 AM on 27 April 2011
       CO2 effect is saturated
       #145 - BP "It is a well known fact thermal conductivity of gases is extremely low." That is something of a cherry-pick, since it ignores the well-known effects of gases in motion. It is a well known fact that thermal conductivity of gases is extremely low, which is why gases make good thermal insulators if the possibility of convection is restricted, as in foams, wool fabrics, compressed straw, etc. It is a well known fact that thermal transfer rate of gases is extremely high if the refresh rate of air flowing over a surface is high, which is why CPUs, air-cooled engines, radiators of water-cooled engines etc. work so well at transferring heat. Fortunately, just like engineers, climate scientists know about convection and allow for it in their models.
87433. KR at 08:28 AM on 27 April 2011
       CO2 effect is saturated
       Berényi - You should, then, be aware that in English "pulled out of thin air" has extremely negative connotations with regard to numbers, namely "manufactured, made up, baseless". If you were not aware of the ramifications of that phrase, that's one thing. If you were intending it with the connotations attached, it's an accusation of data manufacture. Which is it?
87434. Berényi Péter at 07:58 AM on 27 April 2011
       CO2 effect is saturated
       #142 KR at 06:04 AM on 27 April, 2011 Again - are you retracting your accusation of manufactured data? I don't believe I'm alone in finding that deeply insulting to Trenberth et al. Listen, I have not said data were manufactured. It just came from nowhere in that paper, that's all. And this claim is true, you can verify it for yourself. "That 40 W/m² is not substantiated anywhere in the paper. It was just pulled into Fig. 1. out of thin air". Later on I have found the source in a paper written by the same author 12 years earlier, but the 2009 paper lacked any pointer to the source, window radiation is not even mentioned in the text. Also, the calculation in the 1997 paper is somewhat childish, to put it mildly. And presenting a lower bound as a best guess is misleading as well. More importantly, as the lower atmosphere is heated from below (by absorbed short wave radiation at the surface), most of it is either unstable or marginally stable. If there is excess heat at the bottom, it simply overturns the air column, possibly producing some precipitation (and releasing latent heat) as well instead of proceeding upward painfully by repeated radiation emission/absorption events. It is a well known fact thermal conductivity of gases is extremely low. When measuring this quantity, radiative and collisional heat transfer are not separated, so radiative heat transfer inside the atmosphere can't be substantial. Environmental lapse rate is 0.0065 K m^-1 while thermal conductivity of air is 0.024 W m^-1 K^-1 (that of CO₂ is even lower, 0.015 W m^-1 K^-1). It means upward heat transfer without mass exchange is about 0.16 mW/m², which is negligible. If there is a ~23 W/m² thermal flux in a substance along a 6.5×10^-3 K m^-1 temperature gradient (with no mass exchange), thermal conductivity is ~3.5 kW m^-1 K^-1, which is ridiculous. It is more than that of diamond (2.2 kW m^-1 K^-1), the best thermal conductor of all materials. In rare cases when there is a strong thermal inversion, radiative heat transfer may be somewhat larger, but still rather small compared to other fluxes (and its sign is just the opposite). If Trenberth's figures on surface radiation and back radiation are correct, physics tells us the global atmospheric window is some 50% larger than he claims.
87435. Rob Honeycutt at 07:55 AM on 27 April 2011
       Lindzen Illusion #1: We Should Have Seen More Warming
       Argus said... "In my view it is still possible that within another 25 or 50 years, those who live then will see that he was more right than wrong..." Is there any basis for this belief? If so I'd like to hear it. It's my most sincere hope that Lindzen is right, that there is a mechanism in the system that's going to produce much lower climate sensitivity than what is currently being projected. But I'm not seeing much out there to support Lindzen's position.
87436. Bob Lacatena at 07:52 AM on 27 April 2011
       CO2 effect is saturated
       141, BP, I don't quite understand your comment. I think you just have some hurried mistakes in there. Perhaps you can correct them and re-post, or clarify things:

       ...net heat transport of 23 W/m2 from surface to atmosphere by thermal IR radiation...

       The 23 I see in the diagram is reflected visible spectrum radiation. There is also 17 W/m², but that's for thermals, not "thermal IR radiation." It has nothing to do with radiated heat. Beyond this, you say:

       It means the greenhouse effect is saturated indeed.

       I don't follow you. That is, I don't follow how the proportion of energy from thermals to that escaping through the atmospheric window can have anything to do with whether or not the greenhouse effect is saturated, one way or the other. Honestly, I don't see how anyone could ever take any numbers from such a simple schematic and draw any conclusions whatsoever about the CO₂ being saturated. Can you restate your logic more clearly?
87437. Bob Lacatena at 07:45 AM on 27 April 2011
       CO2 effect is saturated
       142, KR,

       I don't believe I'm alone in finding that deeply insulting to Trenberth et al.

       Agreed. Insulting, unfounded, and pretty far over the top (as if his energy budget diagram is or was intended to be anything more than a back-of-the-envelope presentation of energy flow in the system).
87438. dana1981 at 07:24 AM on 27 April 2011
       Lindzen Illusion #1: We Should Have Seen More Warming
       Argus #89 - do you have something of substance to say about this post? "I like Lindzen therefore he must be correct" isn't exactly a very compelling argument.
87439. pbjamm at 07:16 AM on 27 April 2011
       Lindzen Illusion #1: We Should Have Seen More Warming
       Argus@89 "I guess my comment will be seriously snipped" The only insightful thing in your whole comment. I disagree though. It is more likely to be deleted altogether since it is a long winded complaint that has nothing to do with the topic. I for one cant wait to see both of our comments deleted in order to maintain some decorum on this site.
87440. Argus at 07:03 AM on 27 April 2011
       Lindzen Illusion #1: We Should Have Seen More Warming
       Professor Lindzen is the main target on this site now, I understand. The title "Lindzen Illusion #1" forebodes that we will soon see a series of articles like the Monckton Myths numbers 1 thru 16. I have stayed completely out of this site for some months, but now that I returned I stumbled on this Lindzen theme. The purpose is to prove him wrong on point after point by quoting selected reports, as if it was possible to prove anything within climate science. Climate science exists in the vast grey area somewhere in between physics and statistics. You can measure a lot of things daily or year by year, but it is still just weather when the time scale is 10, 20, or 30 years. You cannot test a climate theory in real life, on the real globe itself, unless you allow for a time scale that is too long for a human scientist. Computer models can be built to 'test' a theory, but a good model yields the desired results - those that were in fact built into the model. I have great respect for Professor Lindzen; he is still an established atmospheric physicist and a famous professor of meteorology, and he has written hundreds of publications within the subject of climate and weather. In my view it is still possible that within another 25 or 50 years, those who live then will see that he was more right than wrong (and that the IPCC was wrong about the glaciers in 2035!). On this site, however it is insinuated that he is a charlatan, a liar and a cheater. All this is of course writings by, and intended for, those that already have a certainty of belief in present-day climatology. They know they are right, and that Lindzen is completely wrong, but will any skeptic convinced by this post and these comments? Reading through all the comments to this thread, I recognize about the same 50 guys that all have the same opinions and are full of implicit faith. They have read hundreds of "reports". They are full of indignation over the fact that some professor who has slightly different opinions (a millimeter here, a tenth of a degree there) is allowed to speak in public. Then we have the 5 or so skeptics that are not so easily convinced. Without them there would be almost no discussion. They are told to go read more "reports" and come back later. If they write something considered off-topic, it is officially (-snipped-). That´s new, at least! I guess my comment will be seriously snipped.
       Response:

       [DB] Do you agree with Lindzen or not, per the topic of this post, that we should have seen more warming?  Otherwise your comment is much ado about nothing.  And thus off-topic...

87441. KR at 06:04 AM on 27 April 2011
       CO2 effect is saturated
       Berényi - You continue to use a tabulation summary as a model. I would suggest you obtain a modern copy of MODTRANS or other radiation modeling code and look at the results yourself. You should also (as Trenberth did) cross-examine satellite spectra, cloud coverage estimation on a global scale, and distribution of humidity over both ocean and land. Once you've done so, and backed up your calculations, your numbers can be taken seriously. If operating from a summary that has been adjusted for internal consistency, with considerable uncertainty on some items - not even close. Please cf. my last link in this post. Again - are you retracting your accusation of manufactured data? I don't believe I'm alone in finding that deeply insulting to Trenberth et al.
87442. Berényi Péter at 05:10 AM on 27 April 2011
       CO2 effect is saturated
       #139 KR at 02:33 AM on 27 April, 2011 Very good; looking up the references. Which, I'll note, support the value in the 2009 paper. No, it does not. It supports only a claim the value in the 2009 paper should be at least 40 W/m², but it can be larger by a wide margin. Trenberth fails to mention this detail. Does that matter? Yes, definitely. According to Trenberth there is a net heat transport of 23 W/m² from surface to atmosphere by thermal IR radiation. On the other hand if global average window radiation is more than 60 W/m², this heat transport is negligible and any net heat transport between surface and atmosphere is mediated by thermals and evaporation. That's a big difference. It means the greenhouse effect is saturated indeed. Surface and atmosphere is in radiative equilibrium (as it should) except for the fraction of radiation that escapes directly to space. For example if effective temperature of the surface is 289 K (16 °C), effective temperature of the atmosphere as seen from the surface is 277 K (4 °C) and window radiation is 62 W/m², the above relation holds. Value of net heat transport by radiation between surface and atmosphere has enormous physical consequences, so you can't miss it by 10's of watts and still claim the physics is understood.
       Response:

       [DB] Again, please substantiate, or withdraw, your allegation of manufactured data made against Dr. Trenberth.

87443. johnd at 04:43 AM on 27 April 2011
       Extreme weather isn't caused by global warming
       michael sweet at 16:53 PM, by what measure have you ascertained that current changes are greater than those that occurred during the period being discussed? From 700 to about 1100 AD the region experienced population increases ascribed to to reliable and above average precipitation. This then changed over a very short period into what is described as the 300 year Great Drought. Given the other civilisations that apparently collapsed at about the same time, both in North and South America, also apparently due primarily to changes in precipitation patterns, perhaps the changes were more widespread. Whilst it seems a common feature of many of those earlier societies to believe their Gods were responsible for bringing the rains, hence the rituals and sacrifices, modern day understanding is of how it is the pattern of SST's that primarily determine precipitation patterns, with land use changes and deforestation further influencing regional climates. It is then not surprising that a number of different early civilisations subject to the changing conditions of the same ocean basins would have experienced similar climatic changes related to shifts in SST's and hence precipitation patterns. Interestingly, one of the more long lasting civilisations, the Mayans, developed and built complex systems of water management which perhaps are indicators of both their ongoing need to manage a vital but variable resource, and that success in doing so is necessary to ensure a society not only prospers, but survives.
87444. muoncounter at 04:26 AM on 27 April 2011
       Clouds provide negative feedback
       Documentary evidence that cloud feedback is positive, courtesy of the good folks at the North Pole webcam site: Spring conditions can be cloudy at the North Pole. Clouds are produced when the North Pole experiences Spring warming and the beginning of Summer melting. Water is evaporated from the melting snow surface, forming the fog and low clouds that are seen in Spring/Summer pictures from the North Pole, such as the one on the right from June 2002. In the left image, from 5/1/02 19:06 UTC, the surface is covered by fog and low clouds. Radiation energy is trapped near the surface and thus the temperatures have increased to a very warm 27 F. -- emphasis added [source] Temperature inset at lower left shows 27F as stated.
87445. CBDunkerson at 04:06 AM on 27 April 2011
       Models are unreliable
       trunkmonkey writes: "Any computer model that predicts temperature as whatever convoluted function of CO2 will always be right because they ALWAYS correlate." Excellent. By this statement we would have to conclude that the current rise in CO2 must result in a correlating rise in temperature. Glad to see you are coming around.
87446. Ari Jokimäki at 03:26 AM on 27 April 2011
       Cosmic ray contribution to global warming negligible
       HumanityRules #26: Couple of quotes from Erlykin et al. conclusion section: "Concerning the troposphere,it seems that there is a finite influence of CR on cloud cover at the level of f ~ 1%, a result that is mainly for clouds below about 6.5km, although when averaged over the entire atmosphere it is smaller than this." "Disregarding the latter fact and taking an average f value of 1%, the temperature change consequent upon the changing CC given by the maximum CR change that could be allowed over the last 50 years can be calculated. Over this period the mean CR intensity appears to have fallen by less than 0.6%, using the data of Bazilevskaya et al.,(2008), so that if the conversion, ΔCR to ΔCC and there by to ΔT is known, ΔT can be calculated. Here, we adopt the conversion ΔCC = 11.3% corresponds to ΔT = 0.5°C from the work of Erlykin and Wolfendale(2010). The increase in temperature predicted is 0.002°C,..." By the way, as far as I have seen, very few of the papers that cite Svensmark's old works give support to the hypothesis. Most are neutral (just mention that there is this hypothesis) and many of them are against the hypothesis and show errors in his work. Here are few papers citing his work and showing that he is wrong. There's also a possibility that the whole hypothesis rests on artifacts in cloud data.
87447. Bob Lacatena at 03:02 AM on 27 April 2011
       CO2 effect is saturated
       RE my comment in 137, I inappropriately said "clouds probably absorb substantially more." I should probably withdraw that assumption upon the realization that while clouds cover on average of 2/3 of the surface, they make up considerably less of the total volume of the troposphere (7%, Lelieveld et al., 1989; Pruppacher and Jaenicke, 1995). This means the atmosphere has opportunities to absorb that same radiation before it reaches the clouds (in the lower, denser part of the atmosphere where there is substantially more CO₂ and water vapor), as well as above the clouds. Comparing the outgoing LW radiation by latitude and season versus the cloud distributions by latitude and season demonstrates an even greater imbalance that must be addressed. Obviously, things are a lot more complex, and such a brash, broad assumption was unwarranted. Apologies for the error.
87448. trunkmonkey at 02:43 AM on 27 April 2011
       Models are unreliable
       I just found the NASA publication (Oct 2010)that I think may be the basis for the link at the top of this site about CO2 being the most important control knob. (This link did not work for me) Wow! The GISS model predicts that if all the CO2 in the atmosphere were neutralized GAT would drop to the level of Wisconsin glaciation in the first year! And would drop to levels capable of producing sea ice near the equator in a decade! As a paleo guy I had to put my feet up and think about this one. On one hand the result is utterly absurd and a clear indication that the model parameterizes far too many magical properties to CO2. On the other hand we actually need a mechanism to explain why climate is so bloody unstable. The forams are telling us that even during the prevuously supposed halcyon periods like the Mesozoic the were wild swings in temperature. The F-15 is an airplane whose "forcings" are so strong that no human has the reaction time necessary to fly it and computers are required to smoothe. Perhaps we have an F-15 climate? Water is a likely candidate for the wild thing with two phase transitions within earth temperature range and attendant latent heat as well as "feeds" back, forth, up, down and sideways. Whether CO2 is the moderating agent is debatable. A serious model of earth climate has to account for three things that vary in both duration and amplitude: On a millenial time scale the DO ocillations. On a million year scale the glacial-interglacial episodes within glacial periods. On a billion year scale the glacial periods themselves with 200 million year intervals of higher temperatures. No model even approaches this standard and ( -invective snipped- ). We know that temperature and CO2 have tracked together like mutt and jeff for 800,000 years. The computer models are hypotheses that CO2 has controlled temperature. I am going to ( -invective snipped- ) by advancing a hypothesis that at least until our own efforts may have decoupled them that over all of the Phanerozoic temperature has controlled CO2. What data have we to contradict this? After all, it is what the ice cores have been trying to tell us if we could only break the chains of our preconceptions. Any computer model that predicts temperature as whatever convoluted function of CO2 will always be right because they ALWAYS correlate.
       Response:

       [DB] Please stick to the science and reduce the level of invective.

       CO₂ Control Knob links:

       1. Richard Alley (Video Presentation) 2009
       2. Lacis et al 2010
87449. KR at 02:33 AM on 27 April 2011
       CO2 effect is saturated
       Berényi - Very good; looking up the references. Which, I'll note, support the value in the 2009 paper. Does this mean you are withdrawing your accusation of manufactured data? There are a lot of uncertainties in the numbers Trenberth presents, as is clearly discussed in the article: amounts of convective activity, latent heat numbers from precipitation, large scale estimation of the surface radiance covering sufficient points to cover variation, etc. Others are much more certain: backradiation, insolation, and so on. Taken together, they add up to 10's of watts. Does that matter? No. Trenberth's energy budget is not a GCM, not predictive, but rather an overview of the data available adjusted for internal consistency. Running off and arguing about differences within the range of error of individual element uncertainties is not productive. Such decimal point gaming certainly has no traction in proving/disproving any element of the radiative greenhouse effect. I'll note that this discussion is rather off topic - unless, as you seem to be arguing, that you are attempting to find more evidence for the fact that the CO2 effect is indeed not saturated.
87450. Berényi Péter at 02:13 AM on 27 April 2011
       CO2 effect is saturated
       #136 KR at 22:44 PM on 26 April, 2011 Trenberth may have thought that it wasn't necessary to to spend much time on a value that has been known for >80 years. A value you could have determined with a few moments of web search, I'll note. Really? I thought the proper way to determine values of physical quantities is to measure them. On the other hand Trenberth simply assumes it is 40 W/m². We can get a deeper insight into his thought process if we consider an old paper of his where the problem is elaborated on briefly. Bulletin of the American Meteorological Society, 1997 Earth's Annual Global Mean Energy Budget J. T. Kiehl & Kevin E. Trenberth "Some of the radiation leaving the atmosphere originates near the earth's surface and is transmitted relatively unimpeded through the atmosphere; this is the radiation from areas where is no cloud and that is present in the part of the spectrum known as the atmospheric window, taken here to be the wavelengths 8-12 µm (Fig. 7). The estimate of the amount leaving via the atmospheric window is somewhat ad hoc. In the clear sky case, the radiation in the window amounts to 99 W m^-2 , while in the cloudy case the amount decreases to 80 W m^-2, showing that there is considerable absorption and re-emission at wavelengths in the so-called window by clouds. The value assigned in Fig. 7 of 40 W m^-2 is simply 38% of the clear sky case, corresponding to the observed cloudiness of about 62%. This emphasizes that very little radiation is actually transmitted directly to space as though the atmosphere were transparent". Taken here to be & somewhat ad hoc, indeed. A value of 40 W/m² would imply a broadband thermal infrared optical depth of 2.29 (which roughly means the average photon gets absorbed 2.29 times before it escapes to space). On the other hand this value averaged over the entire surface is below 1.9, that is, total thermal radiation flux escaping from surface to space unimpeded is above 60 W/m². Trenberth's simple calculation makes two omissions. One is the polar window (above wavelength 16 μm), covered only by weak water vapor absorption lines, so in extremely dry regions (like polar ones) a considerable amount of radiation can get through in that frequency band. The other one is clouds. As clouds are always fractal structures, cloud covered surface has a fractal dimension less than 2 (and decreasing poleward). Cloud fraction is usually determined by counting cloudy vs. clear sky grid cells (pixels). However, the finer the grid resolution is, the less the ratio of cloudy pixels will be, because fractals are just like that. It means even in areas categorized as "cloudy" some thermal IR can get through to space unimpeded. Therefore thermal IR radiation flux originating near the earth's surface and transmitted relatively unimpeded through the atmosphere is measured to be more than 40 W/m², Trenberth's back-of-the-envelope calculation is only good as a lower bound. An error on the order of ~20 W/m² in one of the components is a serious one if an average planetary imbalance of less than 1 W/m² is pursued.

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