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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 101951 to 102000:

  1. Stratospheric Cooling and Tropospheric Warming
    Hi All, I think that somewhere in this thread there was talk about the stratosphere being more rarefied than the troposphere. I also think that this was used to justify why the troposphere doesn't cool. The logic was that any emitted radiation in the troposphere would get reabsorbed because of the proximity of the particles. I don't think this is correct. Radiation goes from the stratosphere to the troposphere because the stratosphere is warmer than the upper troposphere. Or did I misinterpret those remarks concerning pressure? Bob
  2. A Cloudy Outlook for Low Climate Sensitivity
    "1. Statistically, and this is important unless you want to throw statistical analysis out with the wash, we have not warmed for the past 15 years." Statistically speaking, unless you want to throw statistical analysis out with the wash, no one has died of tobacco-induced lung cancer in the last nanosecond. Therefore, smoking tobacco is safe.
  3. A Cloudy Outlook for Low Climate Sensitivity
    "On the other point, sensitivity is a function of warming from CO2, not the amount of CO2. " This is still nonsensical, Eric-the-so-called-skeptic, given your earlier post.
  4. The human fingerprint in the seasons
    Haven't had time to read the whole thread; justa adding onto 36 Sphaerica 39 Tom Curtis Actually, an increase in tropospheric H2O would tend to cool the stratosphere; it's a question of how much (H2O partially absorbs radiation from below in some bands, although not as extensively as tropospheric H2O; still, H2O is also at relatively small concentrations in the upper troposphere, and so it should be possible for H2O increase to reduce upward LW radiation at the tropopause in some of the same wavelengths that it can be absorbed in the stratosphere. Of course, if H2O increases in the stratopshere (from climate change? from CH4?), then ...) The seasonal and latitudinal fingerprints are also affected by feedbacks; in particular the surface albedo feedback. The most obvious fingerprint for greenhouse-forced warming (from well-mixed gases at least) in general is upper-atmospheric (above tropopause) cooling and the reduction in the diurnal temperature cycle absent feedbacks (regionally this can be complicated from changes in clouds and humidity and soil moisture and maybe the effect of CO2 itself on evapotranspiration?); others so far as I know require some fine points (finer-scale structures), differences) or more numerical specifications...
  5. actually thoughtful at 15:11 PM on 6 December 2010
    Renewable Baseload Energy
    Archiesteel: "Also, you don't get to determine if you are right or not. That's not the nature of a debate - otherwise everyone would be right, as no one would claim to be incorrect." I disagree with this. If someone can provide good information that is from a credible source and makes sense I would be HAPPY to say "I was WRONG!" And think I won because I now something I didn't know before. I come here to learn from the posts and the comments. The posts I learn by reading. The comments, more often then not, I learn by having to defend my statements or gently (ahem) pointing out (and proving out) the error of other posters' ways. That is the true value of someone like Peter Lang to me - I brush up on what they are saying enough to see their logical fallacies (or that they have a point). I also (post 349) learned enough to come up with my solution to climate change (as it involves electricity - only 40% of the CO2 problem). No small feat! But I would think all of us would be looking for the truth in the others words, and, if finding none, pointing that out, otherwise taking the truth and expanding it or at least claiming it as our own.
  6. A Cloudy Outlook for Low Climate Sensitivity
    Camburn, "1. Statistically, and this is important unless you want to throw statistical analysis out with the wash, we have not warmed for the past 15 years." Why do you insist on repeating the same incorrect information? Several people have now shown you that your assertion is incorrect. You are not being reasonable or discussing in good faith if you insist on repeating false statements and continuing to argue strawmen. "3. Global cloud cover seems to have shifted upwards from a long downward spiral." That may be, although the IPCC states: "In summary, while there is some consistency between ISCCP, ERBS, SAGE II and surface observations of a reduction in high cloud cover during the 1990s relative to the 1980s, there are substantial uncertainties in decadal trends in all data sets and at present there is no clear consensus on changes in total cloudiness over decadal time scales" Also, a 2007 paper found that even the ISCCP data have issues. "Here we show that trends observed in the ISCCP data are satellite viewing geometry artifacts and are not related to physical changes in the atmosphere. Our results suggest that in its current form, the ISCCP data may not be appropriate for certain long-term global studies, especially those focused on trends". Regardless of some people's wishful thinking, the planet continues to accumulate heat and warm. And if the McLean you linked us to @64, is the same discredited McLean behind this awful and debunked paper, then citing "information" from his site is not helping your credibility either Camburn.
  7. A Cloudy Outlook for Low Climate Sensitivity
    Re: Camburn (64)
    "Statistically, and this is important unless you want to throw statistical analysis out with the wash, we have not warmed for the past 15 years."
     Your ongoing focus on insignificant time periods shows you are doing so yourself. Trends in climate science require focusing on the data you have; ideally, 30 years is the accepted period for things to cease being considered weather and to be considered climate. Warming since 1975 is robust. Or are you going by those "feeling lucky" statistics again? The Yooper
  8. A Cloudy Outlook for Low Climate Sensitivity
    Phila: I feel very lucky for numerous reasons concerning climate. 1. Statistically, and this is important unless you want to throw statistical analysis out with the wash, we have not warmed for the past 15 years. 2. Prof Trenbeth talks about the missing heat. I will have to dig to find the paper that I read in the past few months concerning this. The observations at TOA are not what the models show should be happening. 3. Global cloud cover seems to have shifted upwards from a long downward spiral. This would help explain the lack of stastistical warming for the past 15 years. I don't know why it has done this, but it has. http://mclean.ch/climate/Cloud_global.htm
    Response: "Statistically... we have not warmed for the past 15 years."

    This issue is examined in detail at "Phil Jones says no global warming since 1995". The HadCRUT record shows around 93% chance of a warming trend - while this falls a shade below the 95% threshhold to be labelled statistically significant, to move from 93% chance of warming to "we have not warmed for the past 15 years" is a gross distortion.

    Statistically speaking, the NASA GISS temperature record does show significant warming since 1995. The European ECMWF reanalysis also shows a statistically significant warming trend. The HadCRUT record shows a lesser trend as it doesn't include Arctic regions where the greatest warming occurs (Simmons 2010). To claim "no statistically significant warming" is to ignore the fully body of evidence.

    Trenberth's "missing heat" is also address in detail at "Trenberth can't account for the lack of warming".
  9. A basic overview of Antarctic ice
    Bill, I have almost completed my analysis of the globals sea ice data....you are not going to like the results, it seems, with just a few months' data left to analyze that Philippe is correct.
  10. A Cloudy Outlook for Low Climate Sensitivity
    Having read this entire thread, it seems like Camburn has summed up the "skeptical" response pretty well @42: "I feel very lucky." Plenty of good science says that clouds may not make things better, and may even make things worse. But what of it? "I feel very lucky." Which is easy enough to say, when you're unlikely to suffer the worst consequences of being wrong. That's what makes the "skeptical" position morally untenable, IMO.
  11. Eric (skeptic) at 13:39 PM on 6 December 2010
    A Cloudy Outlook for Low Climate Sensitivity
    Dana, thanks for the replies. I agree that increasing CO2 is the correct input to the sensitivity calculation, not emissions, sorry for the confusion (I went on a tangent). I will read and comment at the GCR thread regarding that topic. Sensitivity has to be calculated from the response to local temperature changes since that it the only physical mechanism for such responses. For example an increase in sensitivity could come from increases in arctic WV which come from CO2 warming. A further rise in sensitivity could come from the earlier snow melt (reduced albedo) from that warming, or a cloud change or something else. The parameters and effects are all local and then integrated into local and then global averages. Thus the local effect from UV-induced weather pattern change in your example is very relevant. This is because the water vapor feedback from CO2 forcing is different (e.g. lower UV -> blocking pattern -> large areas of subsidence -> lower UT WV from a given amount of CO2 warming). When a number of local blocking effects are integrated over the planet, that changes the sensitivity for the planet.
  12. Stratospheric Cooling and Tropospheric Warming
    Tom, I changed the paragraph that you commented on as follows: "Consider now the atmosphere of our fictitious model. Nitrogen and CO2 molecules are in motion and the average speed of these molecules is related to the temperature of the stratosphere. Now imagine that CO2 molecules are injected into the atmosphere causing the concentration of CO2 to increase. These molecules will then collide with other molecules of either nitrogen or CO2 and some of the K.E. of these particles will be transferred to the CO2 resulting in excited CO2 molecules and a lowered stratospheric temperature. All entities, including atoms and molecules, prefer the unexcited state to the excited state. Therefore, these excited CO2 molecules will emit IR radiation which, in the rarefied stratosphere, will simply be radiated out of the stratosphere. The net result is a lower stratospheric temperature. This does not happen in the troposphere because, due to higher pressures and shorter distances between particles, any emitted radiation gets absorbed by another nearby CO2 molecule." Bob
  13. Stratospheric Cooling and Tropospheric Warming
    Tom, I'm changing it to reflect your second comment about energy being radiated both up and down. I'm thinking about the first comment. It would explain something that is not pertinent to the mechanism I'm talking about and would make my discussion more complicated. I'm inclined to say that it is at whatever temperature it is and we need not be concerned with how that happened. Thank you, Bob
  14. The human fingerprint in the seasons
    #94: Do I detect a goalpost shift? In #80, you claimed "any forcing which is continuous and as such elevates temperatures ... will be accompanied by strong GHG feedbacks (CO2, H2O) which will carry with them the same signature as a GHG forcing". If seasonal warming differences are such signatures (as per the point of this post), it appears they are not the same. I suppose we can debate why the signatures are different. As to cause of one warming episode vs. the other (a critical point), here is Meehl et al 2004: The late-twentieth-century warming can only be reproduced in the model if anthropogenic forcing (dominated by GHGs) is included, while the early twentieth-century warming requires the inclusion of natural forcings in the model (mostly solar). "It implies that there was no GHG component at all to warming prior to 1979," Not so. Merely that the solar forcing dominates. And that fits the idea that GHG forcings build slowly, as the forcing due GHG concentration is relative to pre-industrial concentration. Compare ln(300/280)= .07 vs. ln(380/280) = .305, a factor of more than 4 to 1.
  15. Stratospheric Cooling and Tropospheric Warming
    Joe, You're talking about mechanism 2 I think and you are saying that although there is less energy in the IR radiation entering the stratosphere, there is more CO2 to absorb it so the energy content may very well be the same. Am I correct? I don't think it works that way. You could triple the number of molecules but if the energy per molecule doesn't change, the temperature would be the same. I remember something like 1/2kT of energy per molecule for each degree of freedom. So if you have a situation with three times the molecules and you have the same temperature, you have three times the energy. After energy is absorbed by the troposphere, the absorption band of the energy is coming from a cooler black body so each molecule would take up less energy. I still don't have a good understanding how the energy absorbed by a molecule, which causes it to vibrate, gets converted Kinetic Energy. Bob
  16. A Cloudy Outlook for Low Climate Sensitivity
    muoncounter: May I suggest these as even more appropriate song lyrics But now they only block the sun, they rain and snow on everyone. So many things i would have done but clouds got in my way. I've looked at clouds from both sides now, From up and down, and still somehow It's cloud illusions I recall. I really don't know clouds at all.
  17. Greenhouse effect has been falsified
    Re: Henry justice (76)
    "It seems to me that the results may be more stunning with water vapor and we should reduce that too."
     You do realize, don't you, that to reduce the overall water content of the atmosphere you first have to reduce it's temperature? Water Vapor imbalances in the atmosphere equalize in approximately 8-9 days, and is highly dependent on the temperature of the air. Increasing concentrations of CO2 in the atmosphere are acting as a forcing, increasing the temperature of the air sufficient to also increase the humidity of the air by 4% (about the volume of Lake Erie). These increases in water vapor act as a feedback to further increase temperatures. The Yooper
  18. Greenhouse effect has been falsified
    I just looked at the CO2 candle and tube demonstration of the so called greenhouse effects of absorbing heat when the CO2 fills the tube. What is not shown and is important is the spectral sensitivity of the sensor tube. Also, I would like to see the same experiment with water vapor being pumped in. I really don't think this is much of a relevant experiment concerning what is happening in our atmosphere. It seems to me that the results may be more stunning with water vapor and we should reduce that too.
    Moderator Response: See the post "Water vapor is the most powerful greenhouse gas."
  19. actually thoughtful at 12:49 PM on 6 December 2010
    The human fingerprint in the seasons
    Phil @ 93 - I kind of liked the WV molecules with the clipboard, interviewing all the molecules bumping into them. As to solar forcing having a different footprint - I think this is true. This is what the article says, and also what muoncounter traces out a different way in 84. But your own point remains muddy. Do you expect solar forcing to have a warmer summer? That is what the data shows? Do you expect a GHG forcing to have a warmer winter? That is what the data shows. I am glad we both agree that HRs original point does not hold - that is what got me into the conversation (after I got out of jail using HR logic). I'll tell the WV molecules to put the clipboards away. They will exhibit less excitement....
  20. Stratospheric Cooling and Tropospheric Warming
    Bob Guercio at 01:23 Id be interested in the exact figures for the reduction in LW emitted (around 15micron) with the increase in CO2... because you are increasing the CO2 in the stratosphere by 260 odd percent... and i really doubt the reduction in LW would offset this... and with a quick over lay of the graphs, it seems to be increasing emission around the 9-10 micron mark(O3 band) Just with a quick play with modtran, it just seems that the radiative sign from the troposphere @ startosphere may be positive... but its just offset, by the increasing radiative losses in the stratosphere with increasing CO2... I dont have time at the moment to go hunting through the input files, this is just from overlaying graphs, so i could well be wrong...
  21. A Cloudy Outlook for Low Climate Sensitivity
    #54: "the only possible conclusion is that GCR did not exceed other factors in the last 30 years, not that GCR has no influence. It clearly has a substantial influence on clouds" Seems like a false dichotomy to me. I second archiesteel (#57); this idea that GCRs will somehow come to the rescue -- and that won't be until the next solar min if ever -- is pure moonshine. Here is the GCR graph from the reference I cited in #26. Neither the recent peak in GCRs or the prior 1997-98 peak did anything to modulate or moderate or block or unblock temperatures. We're still waiting for that 'substantial influence' to make itself known. This is starting to sound like a musical. With my apologies: And where are the clouds? There ought to be clouds. Well, maybe next year.
  22. A Cloudy Outlook for Low Climate Sensitivity
    Albatross - thanks! Eric, I disagree with your statement that GCR flux "clearly has a substantial influence on clouds". If you go back to my GCR article, I addressed this issue. A number of recent studies have demonstrated that GCRs actually appear to play a very minor role in cloud formation. Also as dhogaza noted in comment #56, sensitivity is measured as the response to increasing atmospheric CO2, not to increasing CO2 emissions. The sensitivity to a doubling of atmospheric CO2, which we are currently projected to reach (doubled from the pre-industrial level of 280 ppm) by mid-to-late century, is 2-4.5°C. This accounts for absorption of anthropogenic emissions by the biosphere. And like archiesteel, I've seen no convincing evidence that UV plays a significant role in climate sensitivity. I have seen evidence that it can influence local weather patterns, but that's a different subject, since sensitivity pertains to *global* temperature changes.
  23. Eric (skeptic) at 12:30 PM on 6 December 2010
    A Cloudy Outlook for Low Climate Sensitivity
    #57 archiesteel, there is no GCR counter to AGW in the past 30 years, but there could certainly be GCR warming in the late 20th century or possibly recent GCR-based cooling offsetting some warming. But GCR is not the story here, it is all the factors spelled out in How-we-know-the-sun-isnt-causing-global-warming.html which constantly fluctuate and add and subtract from the AGW warming. By not including them in either paleo studies or in the models that create clouds, we can't say anything about their effect on sensitivity. They can't be ignored just because they were canceled out over the past 30 years. #56 dhogaza, I should probably not have appropriated the term "modulate". Those statements were answers to two different questions. Natural "damping" of CO2 simply means that CO2 is only a forcing and will not be a positive feedback in any time scale we care about (contrary to On-temperature-and-CO2-in-the-past.html where the charts are missing the other factors that control sensitivity) On the other point, sensitivity is a function of warming from CO2, not the amount of CO2. There is no physical link from the amount of CO2 to the amount of water vapor (or any other postulated feedback parameter) except through CO2 warming. Sensitivity is not a constant although it can be averaged over time and over the earth usually by oversimplifying. A function for sensitivity could be something like delta T = CO2 warming times A where A is the amplification determined by how the weather changes both in response to the warming and how the weather changes in response to external factors (those factors are not necessarily other forcings). "A" would also include increases in water vapor.
  24. 2nd law of thermodynamics contradicts greenhouse theory
    AWoL, the claim of "weak" needs to be supported. There's very little that's "weak" about AGW. There are a few unknowns, but the basic physics is straightforward. The claim of "highly tortuous" is relative and therefore unarguable, since the reader/thinker making the claim may be unable to process the concepts involved. If so, this is hardly proof that the theory is in any way weak or flawed, and is more likely a sign that the reader/thinker needs to spend more time developing a comprehensive understanding rather than parroting those who have a more comforting but less physically consistent message. The layman will judge, as you say, but the layman will also believe in--and in fact kill in defense of--2000 year old theories that are still unsupported by any sort of evidence at all. If you're a strong believer in ethical behavior and integrity, think about what happens if you get it wrong and end up partially responsible for a great deal of suffering. As for Corbyn, I'll second Ned.
  25. 2nd law of thermodynamics contradicts greenhouse theory
    AWoL, let's see. (1) The counterarguments are perfectly straightforward. (2) AGW gets along fine with the 2nd law of thermodynamics; there's no stretching at all. (3) Piers Corbyn has a very poor predictive record, which is unsurprising given his unscientific methods. Aside from that, your comment is right on!
  26. Renewable Baseload Energy
    Rob@363: Yes, you can alter the rate of the reaction by the placement of the fuel rods.
  27. Stratospheric Cooling and Tropospheric Warming
    Bob @152:
    One mechanism involves the conversion of translational energy of motion or translational kinetic energy (KE) into Infrared radiation (IR) and the other method involves the absorption of IR energy by CO2 in the troposphere such that it is no longer available to the stratosphere.
    I don't think the first mechanism should be discusses without mentioning the source of the heat the CO2 is radiating away, ie, UV absorbed by ozone.
    Therefore, these excited CO2 molecules will emit IR radiation which in the rarefied stratosphere may simply sail off into space with the associated energy lost forever.
    In fact, approximately 50% of the energy is radiated downward and absorbed by CO2 in the troposphere. It still leaves the stratosphere, which is therefore cooled.
  28. The human fingerprint in the seasons
    RSVP @79, the effect of CO2 is to increase the altitude at which part of the outgoing IR radiation from Earth is emitted. Because it is emitted at a higher altitude, it is emitted at a lower temperature, and hence emits less energy than is emitted at the surface in the same part of the spectrum. Heat capacity has nothing to do with it. You should also note that CO2 is well mixed, while H2O is concentrated in lower altitudes. Lower altitude means warmer, and hence a lesser reduction in the outgoing IR when compared to the surface. Therefore, the GH effect of CO2 relative to water vapour is larger than we would expect simply by comparing their ability to absorb IR radiation, and their relative abundance. Finally, in your comment @75 you completely misinterpret Arrhenius' paper. In particular, you will note on Table 7 he shows an increase in temperature at all latitudes for an increase in CO2, and likewise a decrease at all latitudes with a decrease. Yes, CO2 does moderate temperature differences due to diurnal and seasonal cycles, but because of its moderation of heat flows between the Earth and space, not because of its heat capacity.
  29. 2nd law of thermodynamics contradicts greenhouse theory
    I've been following damorbel's arguments, and the counter arguments which seem weak and highly tortuous. Doesn't the complexity and stretching of the 2nd law of thermodynamics send any alarm bells ringing? Damorbel is certainly not alone and has my support and that of Claes Johnson(Prof Appl Maths,Stockholm), Alan Siddons, and Piers Corbyn, weatherman extraordinaire, latter-day Druid.In fact, he is probably the only pundit that is doing what scientists,as latter-day druids are supposed to do....making predictions that turn out to be correct.....unlike the agw believers. The layman will judge you, as he has done over millenia, by the accuracy of your predictions. Get it right and you'll be respected as gods. Get it wrong and you may be outlawed...or worse. Piers is anti-AGW, yet his predictions have been miles more accurate than the British Met Office....who have actually opted out of giving long-range forecasts.
  30. 2nd law of thermodynamics contradicts greenhouse theory
    Same here. Damorbel is clearly not interested in learning the science, but rather in pushing his own unsupported theories. When someone is consistently being shown wrong and he/she refuses to acknowledge it, then that persons is likely a troll looking for attention. I'll ingore him/her as well.
  31. A Cloudy Outlook for Low Climate Sensitivity
    @Eric: "UV and other components are more useful since UV modulates blocking and blocking modulates sensitivity." You have yet to demonstrate that it does at a significant enough degree to counter AGW. So far, you have failed to do so. As I said before, this idea that GCR are going to counter AGW seems nothing more than irrational wishful thinking. I have yet to see any evidence that leads me to think otherwise.
  32. A Cloudy Outlook for Low Climate Sensitivity
    "archiesteel, TSI is not a very useful measurement. UV and other components are more useful since UV modulates blocking and blocking modulates sensitivity. By damping I meant that about 1/2 of man's contribution of CO2 to the atmosphere is absorbed by nature." How does this affect ("modulate") sensitivity? By definition, sensitivity is related to the amount of CO2 in the atmosphere, not to the amount emitted by humans (or other sources). In other words after consumption by plant life, absorption by oceans, etc has been taken into account.
  33. Renewable Baseload Energy
    I need to research quokka's comments of nuclear load following. I think he's conflating two different things. The fundamental principle with nuclear is that it's either on or off (as I understand it). You can't just stop the reaction and have very limited capacity to alter the rate of the reaction in the chamber. That is not to say the plant itself can not adjust the rate they are generating electricity. But you are, none-the-less, burning nuclear fuel even if the turbines are off.
  34. The human fingerprint in the seasons
    RSVP @85, the most important flaw with your caclulation is that forcing does not rise linearly with increased concentration, but rather with the log of increased concentration. By best current scientific estimate, the change in forcing in watts per square meter is expected to be 5.35 x the natural log of the current concentration divided by the initial concentration. Doing the maths, we then expect a no feedback temperature rise of 0.5 degrees c with an increase of CO2 from 280 to 380 ppm, and a rise of 1.25 degrees c after fast feebacks, once equilibrium is achieved. Given that it takes up to 30 years to achieve the equilibrium responce, the 0.9 degree rise in temperature since 1850 shown in the graph directly above your post seems well within expectations.
  35. 2nd law of thermodynamics contradicts greenhouse theory
    Thanks for digging up damorbel's rap sheet. I'm going to ignore him or her from now on.
  36. Newcomers, Start Here
    Thank you John Cook for the site and the starter series. My background is not science - it is political science. Became interested in BOINC a few years ago and now I contribute millions of CPU cycles to Climate Prediction. The BBC Climate Prediction effort is the largest grid computing project of its kind anywhere. Their purpose is to make climate prediction models more accurate and useful. Are these efforts helpful in actually advancing your science? I have blogged about this a lot. Gypsy Chief Blog Thanks.
  37. A Cloudy Outlook for Low Climate Sensitivity
    Dana, Great post and thanks for covering this important topic. I was hoping SS was going to cover the Lauer et al. (2010) paper and you did not disappoint. Could the "skeptics" please tell us when this supposed (and mysterious) significant negative cloud feedback is going to kick in? It has not kicked in, and the only reliable, coherent data and studies argue against a significant negative feedback. The long term warming continues in the 0.15 to 0.20 C per decade range, as per RSS data and as per Hansen et al's latest paper.
  38. A basic overview of Antarctic ice
    Philippe said: "What is the point of such manipulations?" You misunderstand. Those are not manipulations those are roughly the actual numbers. As Albatross did in post #74 he found significant negative ice in the Arctic in 3 of 5 solstice months he tested. And he found significant positive ice in the Antarctic in 1 of 5. So all the paragraph is an estimate of how the combined polar ice, since they are of opposite signs, ends up with ratios similar to the antarctic instead of the arctic (still negative but a negative ratio similar to the antarctic ratio). The percentages when you multiply them show that to be roughly the case. Thus it is likely that mathematically the change in global sea ice is not statistically significant even though it is in some cases regionally.
  39. 2nd law of thermodynamics contradicts greenhouse theory
    Tom, I came to that conclusion about damorbel many posts ago. If you believe that your own version of physics is right and all textbooks are wrong and you determine not to learn otherwise, then noone can teach you. We are wasting time. I sure hope the person that taught him physics isnt still in a job.
  40. The human fingerprint in the seasons
    84 (muoncounter), I'm not sure you can do that. It's bootstrapping. More specifically, you are trying to prove that there is a unique GHG signature to warming by adopting the premise that warming prior to 1979 was a result of increased TSI (an unsupported premise, but lets skip that), and warming after 1979 was a result of CO2 (GHG). Having thus proved that GHG warming has a different signature (using the premise that warming after 1979 was a result of CO2), you then want to prove that warming after 1979 was a result of CO2, because it has a different signature. That said, I would be interested to hear a climate scientist's take on the fact that all warming of any sort should include substantial GHG feedbacks, and yet the signature warmer winters for GHG are only present after CO2 warming kicked in. This would seem to me to argue against a strong H2O/CO2 feedback. It implies that there was no GHG component at all to warming prior to 1979, and you can't have it both ways, you can't have a climate sensitivity with positive feedbacks that only kick in for CO2 but not for other forcings. Given this, it therefore implies a lower climate sensitivity across the board (which hardly seems to be the case, given the preponderance of other evidence to the contrary).
  41. Eric (skeptic) at 09:45 AM on 6 December 2010
    A Cloudy Outlook for Low Climate Sensitivity
    archiesteel, TSI is not a very useful measurement. UV and other components are more useful since UV modulates blocking and blocking modulates sensitivity. By damping I meant that about 1/2 of man's contribution of CO2 to the atmosphere is absorbed by nature. Since I can't predict solar and GCR, I can't say whether it will mitigate or worsen AGW. Dana, thanks for addressing my assertions, hopefully I can clarify and maybe some are still wrong after I do. I definitely consider CO2 as a forcing, but it has also been considered a feedback in various threads including the paleo sensitivity threads where it is (IMO incorrectly) considered to be the primary feedback, so that's why I mentioned that. The recent warming (2C per century peak rate) has had many short term fluctuations, hardly representative of the long term sensitivity. I agree with your third point, but it consists of a modest warming effect from GHG before considering sensitivity. Methane varies greatly in the short term and no long term sensitivity conclusions can be made. I agree with your fifth point because water vapor will increase on average with evenness being the big unknown. My argument is a little different Lindzen and Spencer as I see a greater effect from external factors, not in their models and not in their critics models, on clouds. You previously dismissed GCR in the thread I linked to only by hypothesizing it as the only factor, comparing the linear trend with linear temperature trend and seeing no correlation. But the only possible conclusion is that GCR did not exceed other factors in the last 30 years, not that GCR has no influence. It clearly has a substantial influence on clouds, but those cloud changes do not directly control temperature but mostly weather. In the past 30 years, other factors, both terrestrial and not, have had a larger influence on weather. The reaction of weather to these factors is what sensitivity is.
  42. 2nd law of thermodynamics contradicts greenhouse theory
    Tom Dayton wrote : "Do you really believe you are the lone genius on Earth who truly understands the second law of thermodynamics?" I think the answer to this, in damorbel's mind, is 'yes'. I'm not being insulting but I think everyone should look at this Wikipedia page, which seems to be the same damorbel going through the same arguments, with others attempting what you are all trying to explain here. What is the point and why should anyone be allowed to do this here ?
  43. 2nd law of thermodynamics contradicts greenhouse theory
    damorbel, you completely missed the point archiesteel made. He was countering your claim that reflection of radiation incoming to the Earth must be matched by reflection of radiation outgoing from the Earth. A large part of the reflection of the incoming radiation is by things on the ground. Since the radiation outgoing from the Earth is headed away from things on the ground, the things on the ground cannot reflect it. So the reflection of outgoing cannot automatically be the same as the reflection of incoming, since the reflectors in the two cases are different.
  44. 2nd law of thermodynamics contradicts greenhouse theory
    @damorbel: it is averaged to obtain the entire planet's albedo, sure, but that doesn't mean this accurately describes the actual reflection at any given location on the globe. Anyway, that's besides the point. You seem not to understand the fact that we are talking about two different types of radiation, i.e. short-wave (visible light, ultraviolet, etc.) and long-wave radiation (infrared). CO2 and greenhouse gases absorb and re-emit the latter, not the former. That is the so-called greenhouse effect. A higher albedo means less of the energy is converted from short-wave to long-wave by the surface, i.e. the latter's temperature doesn't increase as much; therefore a higher albedo value usually means colder temperature.
  45. 2nd law of thermodynamics contradicts greenhouse theory
    damorbel, multilayer insulation works even when its surfaces are not coated with reflective material. Read that article again--carefully this time. Oh, wait, you've now decided the article you yourself first pointed to as support is wrong, now that we have forced you to actually read it. In fact, you believe everyone on the planet but you is wrong--everything that everyone has told you, and everything that we've told you to read, and now something that you told the rest of us to read. Do you really believe you are the lone genius on Earth who truly understands the second law of thermodynamics?
  46. 2nd law of thermodynamics contradicts greenhouse theory
    Re #302 archiesteel you wrote:- "You seem to believe that albedo is solely determined by atmospheric (i.e. "above-ground") conditions, but a lot of the actual albedo is determined by the actual reflectiveness of the Earth's surface (water, rock, vegetation, deserts, polar caps, etc.)." The albedo is the radiation reflected by an object in space, it is the average over the surface.
  47. Positive feedback means runaway warming
    Here's a quote from a 2008 paper, posted on the National Energy Technology Lab website, that uses the Tough +/Hydrate computer code for simulating methane hydrate dissociation. MODELING OF OCEANIC GAS HYDRATE INSTABILITY AND METHANE RELEASE IN RESPONSE TO CLIMATE CHANGE
    Two of the most recent studies, each accounting for the coupled contribution of organic matter decomposition and mass transport, have produced drastically different results. Klauda and Sandler [8] provide an upper estimate of 74,400 Gt of methane carbon in hydrate form (27,300 Gt along continental margins, while Buffett and Archer [9] used both compaction and advection in a 1-D methanogenesis/hydrate formation model to reach an estimate of 3,000 Gt of methane in hydrate and 2,000 Gt of gaseous methane existing in a stable state under current climate conditions.
    This paper seems to show increased levels of hydrate release for shallow hydrate deposits with less than a one degree C temperature increase. There are chemical reactions that oxidize the methane or transform it into bicarbonate that I was not aware of until recently. Still, the bigger the reservoir, the smaller the percentage that has to dissociate to cause the climate serious or catastrophic harm.
  48. A Cloudy Outlook for Low Climate Sensitivity
    Eric #50, you've made a number of incorrect statements. Firstly, that CO2 has been a slow feedback at times in the past does not mean it must always be a slow feedback - that's a basic logical fallacy. Besides which, it's not currently a feedback, it's a forcing. Secondly, the planet is already warming at nearly 2°C per century, so it's already not acting slowly. Third, while future changes in solar and other natural factors are hard to predict, that's not really relevant. Maybe the Sun will be a positive forcing, maybe a negative one, maybe a neutral one. What we do know is that greenhouse gases are a large positive forcing which will continue to have a warming effect. Fourth, permafrost is already melting and releasing methane, thus you're once again contradicting empirical observations by claiming this feedback will take centuries. Fifth, there's not much question that water vapor will be a positive feedback, the only real question is how strong that feedback will be. Sixth, it's the argument of Lindzen and Spencer etc. that a negative cloud feedback will prevent significant warming. I didn't make it up - I was addressing their argument. And seventh, the galactic cosmic ray influence on the global climate has been demonstrated to be minimal.
  49. 2nd law of thermodynamics contradicts greenhouse theory
    Re #303 Tom Dayton you wrote:- "apparently you really did not read the article you linked to. Go read it. Really, read it. Notice the explanation of the non-reflective mechanism by which it operates." You are right. But the article, which says :- "the principle behind MLI is radiation balance. To see why it works, start with a concrete example - imagine a square meter of a surface in outer space, at 300 K, with an emissivity of 1, facing away from the sun or other heat sources. From the Stefan-Boltzmann law, this surface will radiate 460 watts. Now imagine we place a thin (but opaque) layer 1 cm away from the plate, thermally insulated from it, and also with an emissivity of 1. This new layer will cool until it is radiating 230 watts from each side, at which point everything is in balance." is wrong; it says (5lines down) "and also with an emissivity of 1. This new layer will cool until it is radiating 230 watts." The whole principle of reflective insulation is using material with low emissivity. Initially satellites used gold plating as a barier against heat tranfer. Gold has an emissivity <0.05, depending on the finish. Also the well known silver teapot (emissivity = 0.02 - 0.03) has only one emitting surface, it keeps the tea hot better than any other material. Further, the vacuum flask the vacuum flask has only two layers and achieves far greater insulation than the explanation given in the 'Multi Layer article. When you write :- "Notice the explanation of the non-reflective mechanism by which it operates." I do not know what you mean. These materials work best in a vacuum which is the case for Sun/Earth heat transfer. In #304 you write:- "reflection (scattering) does depend on frequency. That's why the sky is blue." This wavelength dependence of scattering has no effect on total transfer of heat when at the equilibrium temperature, if it did there could be no equilibrium.
  50. The human fingerprint in the seasons
    actually thoughfull (way back @74 on molecules being interviewed) No this was not what I was suggesting :-) The point was that if there was a solar forcing causing increased WV in the atmosphere, then wouldn't the concentration of WV in the atmosphere (and hence the feedback) follow the forcing as it moved from hemisphere to hemisphere because of the differing temperatures of the atmosphere over the summer and winter locations. In contrast a CO2 forcing would not have a seasonal fluctuation and so the seasonal feedback (WV) variation would be less. If this were true then HR's objection to the original article is invalid: even with WV feedback, a Solar forcing would still result in summers warming faster than winters. Any clearer ?

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