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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 102151 to 102200:

  1. Stratospheric Cooling and Tropospheric Warming
    Bob 165 That was exactly the point I tried to make earlier up the thread - that at very low CO2, where tropospheric absorbtion isn't significant, you'd expect increased absorbtion in the stratosphere, hence increased temperatures ie for x Co2 concn radiation coming through from surface in the CO2 window = (1-x) absorption in the stratosphere = x Total warming effect = x(1-x) ie heating at low conc, net cooling at higher concs
  2. The human fingerprint in the seasons
    #47 muoncounter My first point is that in the tropic band the majority of heat absorbed from the sun is absorbed in the ocean because the ocean comprises the majority of the earth's surface in that band. And CO2 energy absorbtion doesn't have the same effect over the ocean that it does over land because the ocean re-radiates almost nil energy via radiation. Solar radiation that goes in the water stays in the water unless released through evaporation and convection. You can see this by following the tracks of hurricanes using sea surface temperature. So my second point is that solar radiation that is absorbed by the ocean in the tropics can be transported northward without regard to CO2 effects. As far as see ice formation under the ice, I say this because I have seen it. I watch too much TV. NOVA had a penguin with a camera go under the ice. You could see the ice crystals accumulating under the antarctic ice shelf. The little fish the penguins eat live amongst the ice crystals. The commentator also made a comment to this effect.
  3. A Cloudy Outlook for Low Climate Sensitivity
    @Eric: " 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." There is no indication this will happen, or that it will be significant enough to counter AGW. Until you provide some evidence, we'll have to remain skeptical about your unsupported claims. "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." Which factors are you talking about, exactly? It really sound as if you're grasping at straws here, like your fellow skeptics damorbel, Camburn and RSVP. I don't even know why we're arguing anymore, as you guys clearly have nothing.
  4. Renewable Baseload Energy
    @actually thoughtfull: "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!" That has nothing to do with what I said. Did you even read what I wrote? I said one cannot claim they are right in a debate - it is for others to judge if your argument has merit or not (assuming everyone is debating in good faith). That's twice you've appeared to misinterpret my posts. Please stop.
  5. Stratospheric Cooling and Tropospheric Warming
    The Ville @162, Bob's description is correct. The vibrational modes of atoms within a molecule enter into the equation as the heat capacity of the molecule, and not as temperature. This is discussed at the Wikipedia article on heat capacity As the caption of a nifty graphic puts it:
    "Molecules undergo many characteristic internal vibrations. Potential energy stored in these internal degrees of freedom contributes to a sample’s energy content, but not to its temperature. More internal degrees of freedom tend to increase a substance's specific heat capacity, so long as temperatures are high enough to overcome quantum effects".
  6. A Cloudy Outlook for Low Climate Sensitivity
    @Camburn: can you please acknowledge you were proved wrong in your claim that there hasn't been any warming since 1995? I'm going to continue reminding you until you do...
  7. A Cloudy Outlook for Low Climate Sensitivity
    CBDunkerson @73, "Just out of curiosity, is there a temperature point at which our local 'skeptics' would conclude they've made a mistake?" Excellent question, and one that is likely to unanswered. These tactics employed by the "skeptics" are ultimately about delaying taking action. Spencer's estimate of +1.7 C for fast feedbacks will buy them is smarter than that of Lindzen, as it will buy them more time. Lindzen is flat wrong, and the global SAT data (and work of Murphy and Trenberth et al.) have shown him to be wrong for many years now.
  8. A Cloudy Outlook for Low Climate Sensitivity
    Mark R @70, "They think that in a warmer world, clouds will change to have a larger cooling effect than they do now." Three points. One, sorry but what they "think" is not good enough for me, and it should not be good enough for you either. Wishful thinking is not going to get us out of this mess. Two, Lindzen says climate sensitivity for doubling CO2 is around +0.5 C, which suggests that a strong and negative cloud feedback should have kicked in after we warmed by about +0.5 C. The planet has not yet and we have warmed by over 0.8 C (for a 40% increase in CO2), and the rate of long-term warming continues at 0.15 to 0.2 C per decade. Three, Spencer estimates climate sensitivity (for fast or Charney feedbacks) near +1.7 C. Over three times higher than Lindzen, and withing the range specified by the IPCC. So even Lindzen and Spencer are at odds.... I repeat my question from earlier. When is this alleged significant negative cloud feedback going to kick in? It did not kick in after +0.5 C warming as Lindzen's work suggests it should have. The mystic "iris affect" is now looking to be on as shaky ground as the long-debunked GCR fiasco.
  9. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    "It is difficult to get a man to understand something when his job depends on not understanding it." - Upton Sinclair
  10. The human fingerprint in the seasons
    Patrick 027 @99, an increase in tropospheric water will not significantly cool the stratosphere. Although the increase in tropospheric water will decrease the outgoing radiation in wavelengths where water vapour absorbs, in those wave lengths there are no significant absorbers in the stratosphere. Therefore the reduction in radiation in those wavelengths will not result in a reduction in energy being absorbed by the stratosphere. Chris G @100, when adding CO2 to the troposphere, it will initially reduce outgoing IR in the 15 micron wavelenght band. As the atmosphere approaches equilibrium, this IR radiation will tend to increase towards its prior value, but will never reach it. That is because the total outgoing radiation before the disturbance and after equilibrium is reached will be the same, but because the surface is hotter, IR radiation in those wavelengths not absorbed in the atmosphere will carry more energy. To preserve equilibrium, it follows that those IR wavelenghts which do face atmospheric absorption must carry less energy.
  11. Stratospheric Cooling and Tropospheric Warming
    Hi All, Regarding a professional critique, I shot off an email to John Cook. He may have some clout with the professionals at Real Climate. Bob
  12. Stratospheric Cooling and Tropospheric Warming
    The Ville - 162 I agree. That's why I referred to temperature being caused by Translational kinetic energy rather than just kinetic energy. Do you still think I need to make this clearer? Or are you referring to something else I said in my blog where I may have said something wrong? Thanks, Bob
  13. Stratospheric Cooling and Tropospheric Warming
    Joe Blog - 160 I think that I see what you are saying. I have explained two mechanisms for cooling but there is a mechanism for warming the stratosphere because of the extra CO2 in it. More CO2, more warming due to absorption of radiation passing through from the troposphere. I think that this is an interesting thought but I don't think it would have any effect on my writeup and would only add an unnecessary level of complexity to it. Maybe someone can address this point. Bob
  14. 2nd law of thermodynamics contradicts greenhouse theory
    Re #319 Ned you wrote:- ""Albedo" is just the average spectral reflectance across a broad range of the spectrum. That's all that it is." And you cited my #318:- "It is the magnitude of the albedo, not the wavelength function, that governs energy transfer" Did it occur to you that these may be the same thing? We seem to be in agreement. So do you also agree that the albedo is not a 'one way' effect? That the material making the reflections that produce the albedo, water, ice, desert sand, clouds etc., also can reflect back some of the Earth's thermal radiation, in the manner of total internal reflection, as I described in #317? Or do you subscribe to the idea that radiation from Earth is completely unhindered, just like that of a theoretical black body?
  15. 2nd law of thermodynamics contradicts greenhouse theory
    AWoL wrote : "I've been following damorbel's arguments, and the counter arguments which seem weak and highly tortuous." Could you list what darmobel's arguments are and which particular "counter arguments" are "weak and higly tortuous" ? Can you give more detail ? AWoL also wrote : "Doesn't the complexity and stretching of the 2nd law of thermodynamics send any alarm bells ringing?" Again, can you give more details of the "stretching" ? As to this all being complex : well, you don't say ! That doesn't mean that anything in particular, involving the 2nd Law or AGW, is wrong, does it ? Or can you point out what you believe is wrong ? AWoL then wrote : "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." The usual so-called skeptical reliance on lone voices, especially weathermen ! Tell me : how can you tell when those lone voices are so far out there that they are beyond rational science ? Does that ever bother you, or do you accept the creationist view of life on earth too - i.e. the lone voices ? As for your use of the word "Druid", that suggests to me that you have a religious basis for your beliefs, so maybe creationism IS your favoured view of life on earth ? AWoL also wrote : "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." Uh oh, that religious angle again. You would be better looking for scientists who are NOT "latter-day druids" (whatever you believe that means), and stick to scientists who work in the fields in which they are pronouncing. AWoL wrote : "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." Love the implied threath there : "or worse". Why don't you reveal what will happen to anyone who uses the scientific method without being able to get 100% results, i.e. just about every scientist in any field you care to mention. And, once again, try to leave religion out of this, please. AWoL finally wrote : "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." Do you have any evidence of the predictions of this druid of yours, so we can see how good he is at crystal-gazing ? By the way, the Met Office no longer do seasonal forecasts, as they recognise the difficulty of predictions for this time-period, and they know that any wrong word will be taken out of context and abused by the denialosphere.
  16. Eric (skeptic) at 01:01 AM on 7 December 2010
    A Cloudy Outlook for Low Climate Sensitivity
    #73 CBDunkerson, very roughly I would go by something like this: http://www.drroyspencer.com/wp-content/uploads/UAH_LT_1979_thru_Nov_10.gif with (very roughly) 0.1 per decade per 1C sensitivity. Right now it looks like about 0.2C per decade especially if the current strong La Nina takes us only back to 0.2 on the moving average.
  17. Stratospheric Cooling and Tropospheric Warming
    VeryTallGuy - 161 I think I'm starting to understand and have enjoyed the thread, but I'd suggest the final version needs a proper academic critique as we've shown just how easy it is to get it wrong. I couldn't agree more. I'm not exactly sure how I'm going to get that critique because, in general, professionals don't bother with amateurs. This is understandable because there is such a vast difference in the scope of their knowledge. It could be different here because I am not debating with a professional but only asking that they check it for accuracy. I too am understanding this more and more every day. There is really nothing astounding in all of this. It is just a combination of elementary Physics concepts; however, when you put so many elementary Physics concepts together, it does get a bit confusing! Bob
  18. A Cloudy Outlook for Low Climate Sensitivity
    So let's see; 1: We have observations of CO2 and temperature for the past 130 years or so. We also have various satellite observations of temperature and cloud correlations for 30 years or so and sporadic visual accounts prior to that. These show that we are on track for a climate sensitivity of about 3 C. 2: We have proxy records of CO2 and temperature for hundreds of thousands of years (billions for some proxies). These consistently show a CO2 and temperature correlation, and the more recent / most solidly established fluctuations suggest a climate sensitivity of about 3 C. 3: We have climate models built on measured impacts of the physical and chemical processes impacting climate. These suggest a climate sensitivity of about 3 C. Ergo, the 'skeptic' response is 'climate models cannot be trusted', 'proxy records are incorrect', and 'observed temperatures have just recently turned around and will now begin cooling rapidly'. That last being updated to a new turnaround date every ten years or so. Just out of curiosity, is there a temperature point at which our local 'skeptics' would conclude they've made a mistake? Presumably if we hit a 3 C temperature anomaly within a few decades after doubling CO2 most (sadly I'm sure not all) would concede the point... but what about 2 C? Some claim climate sensitivity is only 1 C per doubling... but we're already over 0.8 C anomaly at 39% increase over the previous nearly flat CO2 level. At the current rate we'll pass 1 C this decade. Will that be enough to silence the 1 C crowd? Or will the 'temperature records are faked / unreliable' nonsense just be ramped up to cover? On the flip side, if CO2 climbed to 420 ppm without temperatures breaking 1 C I'd start to think 3 C sensitivity might be a little bit high. If we got to 490 ppm without breaking 1 C then sensitivity would probably only be about 2 C. All of this is 'fast feedback' sensitivity of course. On the multiple centuries scale we can expect another 50% or more warming over these figures.
  19. Ocean acidification isn't serious
    Chris Shaker, The changes in tropical temperatures during the glacial/inter-glacials was much smaller than the global average, "probably" 1-2 degrees change. Most of the large temperature swings occurred at high latitudes and especially the Northern Hemisphere where continental ice sheets formed. This small change is temperature in the tropics is why the tropical rainforests were not greatly affected by the ice ages. Precessional changes (wobbles in the Earth's rotation) which affect the amount of solar radiation at the equator are thought to have had a greater significance. Localized coral bleaching is not a new phenomenon, however mass coral bleaching is, certainly within the last several hundred thousand years.
  20. A Cloudy Outlook for Low Climate Sensitivity
    MarkR, how does a hypothetical strong negative cloud-albedo feedback allow for the existence of glacial/interglacial cycles? Or millennial-scale climate variations such as the MWP and LIA?
  21. 2nd law of thermodynamics contradicts greenhouse theory
    damorbel & AWoL, the simple fact is that the stuff damorbel is saying is on the level of 'the earth is flat', 'the sun orbits the earth', and 'the earth is only 6000 years old'. It is completely at odds with science that has been considered established fact, based on hundreds of lines of evidence, for over a century. If you believe otherwise you are either a nutjob or a revolutionary genius. However, if you want to prove that you are a genius, and not a nutjob, ranting on the internet does not seem the most effective approach. If you think you've found some amazing and clear evidence which disproves the greenhouse effect (which mainstream science considers to have been proven by Tyndall in 1858) what you should be doing is publishing your findings in science journals. Trying to argue it out here, while the textbooks still contradict you, just leads people to the 'nutjob' conclusion.
  22. 2nd law of thermodynamics contradicts greenhouse theory
    damorbel writes: the wavelength function of Earth's albedo alone is irrelevant because it doesn't include the magnitude (wavelength independent part) of the albedo. It is the magnitude of the albedo, not the wavelength function, that governs energy transfer More anti-mathematical gibberish. AWoL, is this really the person you want to be following? "Albedo" is just the average spectral reflectance across a broad range of the spectrum. That's all that it is. Whether a particular photon is absorbed or reflected by a surface depends on the spectral reflectance of the surface at that particular photon's wavelength. It doesn't depend on the generalized average reflectance of the surface across a wide range of wavelengths (albedo).
  23. A Cloudy Outlook for Low Climate Sensitivity
    I don't really want to go off on a tangent here, but even if cloud-feedback on climate-sensitivity were low as some hope, this would only apply to the increase of temperature, but it wouldn't prevent further ocean-acidification, would it? So, from the "evil twin of climate change" point of view clouds don't really play a role. I often have the impression that ocean acidification is kept out of the limelight by "skeptics" as many of their lines of thought like cloud-feedback or geo-engineering don't help with that at all.
  24. 2nd law of thermodynamics contradicts greenhouse theory
    Re #315 Ned you wrote:- "2) AGW gets along fine with the 2nd law of thermodynamics; there's no stretching at all" The original argument for AGW is that "Earth radiates like a black body", that is how a supposed equilibrium temperature (without GHE) of 255K is calculated. It is this 'never justified assumption' (check p3 for a 'list of assumptions') that means the AGW 'science' breaks the 2nd Law of Thermodynamics. The fact that Earth manifestly is not a black body (because it has an albedo) destroys the GHE temperature calculation completely. Trying to sustain this by observations about a wavelength function do not account for the fact that the wavelength function of Earth's albedo alone is irrelevant because it doesn't include the magnitude (wavelength independent part) of the albedo. It is the magnitude of the albedo, not the wavelength function, that governs energy transfer, as explained in #317.
  25. Stratospheric Cooling and Tropospheric Warming
    #159 It doesn't matter if troposphere is colder - radiation goes both ways regardless of temperature gradient. Net heat transfer must be from hotter to colder, but not necessarily radiative.
  26. Stratospheric Cooling and Tropospheric Warming
    Bob Guercio: "Temperature depends only upon the kinetic energy of the molecules. Thus, after a collision, a molecule with no vibrational energy may now have vibrational energy and that molecule has less kinetic energy. So this diminution of kinetic energy from multiple molecules lowers the temperature. That molecule that has more vibrational energy deexcites and emits IR that may be absorbed by another deexcited molecule or it may simply fly off into space. This IR flying off into space is kinetic energy that is now lost forever from the stratosphere." Molecular vibration is kinetic energy Bob, because the molecule is moving. eg. if you have a lump of steel that is red hot, the molecules vibrate a lot, they don't fly about, except at the surface. http://en.wikipedia.org/wiki/Temperature
  27. 2nd law of thermodynamics contradicts greenhouse theory
    Re #307 Tom Dayton you wrote:- "multilayer insulation works even when its surfaces are not coated with reflective material." All material reflects, or more accurately, scatters radiation; mirror type reflection or indeed refraction, is called coherent scattering because the phase relationship of the incoming radiation is (largely) preserved. Coherent or not, scattering reduces the transmission of radiation through a given aperture (the Earth's disk?) This reduction is independent of the direction of the source. This means that, if the Sun's incoming radiation is reduced by factor called the Albedo, then the outgoing thermal radiation will be reduced by the same amount. The magnitude of the scattering function may well be subtantially independent of wavelength as with transparent materials such as water but that doesn't mean the radiation is not redirected away from absorption/emission. For example clouds (water) contribute substantially to the albedo because the droplets are very small, whereas the oceans (water) which appears dark in images of the Earth appears to make a much smaller contribution to the albedo. Liquid water (70% of Earth's surface) having a relatively smooth surface, allows sunlight to get to depths far greater than its wavelength where it gets gradually absorbed. Only a limited % of the radiation penetrating the water surface remerges because of the phenomenon of total internal reflection, an example of coherent scattering. This total internal reflection phenomenon applies equally to radiation originating (thermally) under the water surface, it means that thermal radiation is, to a certain extent, trapped there, reducing its emissivity in proportion and thus water (70% of... remember?) cannot radiate like the black body central to GH effect theory.
  28. A Cloudy Outlook for Low Climate Sensitivity
    RE: #10 David Horton = Lindzen and Spencer's position makes sense. They think that in a warmer world, clouds will change to have a larger cooling effect than they do now. This _is_ a long term solution and it leads to a lower climate sensitivity than the IPCC give. We could probably risk 1,200 ppm CO2 if their strongest hypothetical values are right.
  29. Stratospheric Cooling and Tropospheric Warming
    Bob, two suggestions, 1) If increased emissivity of the stratosphere rather than decreaased transmission of surface emissions through the tropsphere is the main cause, can this be shown graphically? eg by showing the emissions spectrum just for the stratosphere for different CO2 concentrations, at equal total power. This would show the higher emission in the CO2 bands and the corresponding lower temperature necessary to get the same total power out(ie area under the graph). It would, though, require someone to do the calcs which is way beyond me. It might be good enough to do this as a single slab for the stratosphere, just to show the principle? 2) From your link "Since power is energy per unit time, the energy content of IR radiation can be indicated by its IR spectrum which is a graph of power density as a function of frequency." I'd suggest the unit time bit here is unnecessary and confusing - we are not looking at dynamics. I think I'm starting to understand and have enjoyed the thread, but I'd suggest the final version needs a proper academic critique as we've shown just how easy it is to get it wrong.
  30. Ocean acidification isn't serious
    These seem like pretty massive and rapid climate changes to me. Indeed, they would affect any coral reefs growing around Greenland. I'm not aware there was, but if there was. Moderator: There isn't a coral rebuttal or post (yet). I didn't realize all those coral "arguments" existed.
  31. Ocean acidification isn't serious
    scaddenp: I put the sources detailing recent dramatic temperature shifts here, because we're talking about the inability of coral to deal with dramatic temperature shifts. It seemed surprising to me. Chris Shaker
  32. We're heading into an ice age
    scaddenp: I'm not suggesting it. The author of that paper was suggesting it is possible. The idea was fascinating to me. Been obsessed with reading about the ice age cycle lately. I have read Barney Oliver's analysis of the energy difference due to the Milankovich cycles. Such an elegant and sparse argument he made. Was a brilliant man. Chris Shaker
  33. Stratospheric Cooling and Tropospheric Warming
    Bob Guercio at 15:30 Temperature reduces with altitude in the troposphere, because of the reducing pressure with altitude in the troposphere. And thus the shortening of the optical pathway. This is correct. (Truth is convection moves the bulk of the energy at low/mid altitudes in the troposphere, the optical path is too long for radiation to effectively move it, but this energies escape is limited by the path length at higher altitudes in the troposphere. By adding CO2 it is raising the height that radiation can effectively escape. The warming of the lower atmosphere is a necessary result, to enable the T differential between layers to allow the transfer of energy up to this higher altitude, through convection, conduction and radiation.) The net transfer of energy from the stratosphere to the troposphere, is because the stratosphere is warmer than the upper troposphere, because it absorbs UV, but has a short optical pathway for transferring this energy once in the co2 bands... So LW energy can pass straight through it without interacting from the troposphere up, and also from higher up back down, until it is absorbed by the thicker atmosphere of the upper troposphere. And this is why i am a lil curious on the figures for the change in radiation, because by increasing CO2, not only will it radiate energy out of the stratosphere more efficiently, but it will absorb more of the radiation in transit up, that would have previously passed through. But i dont think i was correct on the increase in the 9-10 micron area. But would be curious to the exact figures. radiation dosnt care whether its being absorbed by a warmer or colder body, it will be absorbed by what it is incident on pending its "properties". Although intensity is an important consideration.
  34. A Cloudy Outlook for Low Climate Sensitivity
    @Camburn:"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." As the past decade has set temp. records, this claim rather shocked me, so I took the raw GISS data http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts.txt and did a linear regression analysis for the past 15 years. The result? The slope is 0.0250 degreeC per year, with standard deviation 0.0027. This means that with a 95% confidence, the temperature increase over the past 15 years was between 0.02 and 0.03 degreeC per year. Or, the total increase over those 15 years was between 0.30 and 0.45 degreeC, with 95% confidence. So Camburn, you are using different data? Could you share it with us?
  35. The human fingerprint in the seasons
    Patrick 027 (#99), I think you'll find we've hashed this out already. My take-away points are that H2O will yield a stratospheric cooling by restricting outbound flow, and CO2 will yield a cooling by not only restricting the outbound flow, but also enhancing the stratosphere's ability to radiate energy.
  36. The human fingerprint in the seasons
    RSVP, I'm not sure you properly understand the concept of heat capacity. You said, "...but does not "retain" any more heat than its specific heat capacity allows.", which I take to mean that you think there is a limit to how hot CO2 can get. Your own link covers a temperature range of 175K to 6000K and I'm pretty sure the range you'll find in our atmosphere is within this range. Heat capacity does not limit how much energy a substance can hold, it describes how much energy is required to raise a unit mass's temperature one degree. Tom (#96), I've another nit with something you said, "Because it is emitted at a higher altitude, it is emitted at a lower temperature,..." In time, energy in always equals energy out. The mean point of emission does rise to a higher altitude at that time, but its temperature is the same as what it used to be. You get a warming at the surface by following the lapse rate down. Although, if you mean at a time prior to some new equilibrium being reached, then you are entirely correct. Otherwise, I concur with what you said, and I take back what I said about it would be hard to tell a H2O signature from a CO2. This is mostly because I remembered that H2O concentration varies not only with altitude, but also with latitude. There is a lot less of it in high latitudes; so, I think the polar amplification would not be as much. Which leads me to a thought on Sphaerica's comment, "...you can't have a climate sensitivity with positive feedbacks that only kick in for CO2 but not for other forcings." Certainly true, but it strikes me now that feedbacks might come into play at different rates or different degrees dependent on what the driver is. For instance, with a more uniformly distributed GHG like CO2, you might expect more polar amplification than you would with a solar forcing driving up H2O first, which will be less well distributed. There are interesting things going on now with polar albedo, melting permafrost, and methane release that would be delayed with less of a polar amplification effect. Really curious if I'm on to something with this; though, it's mostly academic.
  37. 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
  38. 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.
  39. 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.
  40. 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...
  41. 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.
  42. 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.
  43. 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
  44. 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".
  45. 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.
  46. 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.
  47. 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.
  48. 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
  49. 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
  50. 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.

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