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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 101101 to 101150:

  1. Lindzen and Choi find low climate sensitivity
    RW1 "4 W/m^2 would the total that affects the surface only if all the absorbed power is directed back toward the surface, but only about half of it does because GHG infrared absorption and re-radiation is in all directions - i.e. about half goes down and other half goes up out to space in the same general direction it was already headed" I have already pointed out twice that this is simply plain wrong. The point on emissions being both up and down is irrelevant - the calculation already takes account of the fact that emission is isotropic. No amount of you baldly stating the opposite makes the fact go away. Doubling CO2, devoid of feedbacks, adds 4W/m2 to the Earth's energy budget. When you insist on quoting again and again, without references something plainly wrong, there's no point in any "debate".
  2. Stratospheric Cooling and Tropospheric Warming - Revised
    Excellent work, Bob ... but my final point of confusion was cleared up by this comment from Jeff T. You might want to consider adding it to the main text: "The characteristic vibrational energies of O2 and N2 are relatively high; they are not excited by collisions in earth's atmosphere. CO2's characteristic energy is lower. Its vibrations are excited by collisions in the atmosphere." Thus the more CO2, the more energy is lost via radiation.
  3. Lindzen and Choi find low climate sensitivity
    Riccardo (RE: Post 36), I know the feedbacks are not included in the 4 W/m^2 (2 W/m^2 net) - that is why the actual response is greater than 2 W/m^2 or about 3.2 W/m^2 (or 6.4 W/m^2 if all the absorbed power is assumed to be directed back to the surface). The point is even if all the power is directed back down, the temperature increase would still only be about 1.2 C, which is significantly less than the 3 C predicted (390 W/m^2 + 6.4 W/m^2 = 396.4 W/m^2 = 289.2K). No one has yet to really address the initial question, which is what's so special about 1 W/m^2 additional of power from CO2 that the system is all of the sudden going to treat it as being at least 5 times more powerful than 1 W/m^2 of power from the Sun?
  4. Lindzen and Choi find low climate sensitivity
    RW1 feedbacks are not included in the 4 W/m2 and you're still separating the whole system into two parts. It does not work this way. Try the enrgy balance of the earth as a whole.
  5. Debunking this skeptic myth is left as an exercise to the reader
    @muoncounter #51 I wasn't thinking in fine psychology but something in the style of The contradictory nature of global warming skepticism. For me, paragraphs like
    It's a testament to the robustness of the AGW theory that skeptics can't seem to decide what their objection to it is. If there were a flaw in the theory, then every skeptic would pounce on it and make a consistent argument, rather than the current philosophy which seems to be "throw everything at the wall and see what sticks."

    are worth a gold ingot because almost everyone can understand them. With these kind of messages, people who can't follow the arguments suddenly understands what's going on 'behind the scenes'. No wonder some 'big shot' who drives real funding to GW denialism felt the need to comment on that post.

  6. Lindzen and Choi find low climate sensitivity
    @RW1: cherry-picking. That graph is for a single region, not a global average. It is well known certain areas see greater variability, especially near the poles. For example, the current Arctic anomalies are more than twice the global one (which is 0.8, not 0.6), putting them in the high end of what this graph shows. Never mind the fact that most of the warming has occured over the last 40 years, not century. Nice try, but this has been debunked here countless times. Perhaps you should actually learn the science on this site before arrogantly claiming to overturn decades of climate science with your old and tired talking points?
  7. Lindzen and Choi find low climate sensitivity
    RW1 writes: "Due to the logarithmic response of CO2, an increase from 280 ppm to 380 ppm equals about 75-80% of the forcing from a doubling of CO2." Forget about learning the science... you aren't going to get anywhere until you learn math. ln(380/280)=0.305382, or about 31%... not 75-80% Also: "75% of 3 degrees C is 2.25 degrees C." Which, in addition to the incorrect starting factor, would assume that all the warming feedbacks were instantaneous... which is not what climate science projects. It will take decades after any given CO2 level is reached for all the FAST feedbacks to play out and centuries for slow feedbacks to complete. Also: "During the period from about 1900-2000, the amount of warming was only about 0.6 C" The CO2 level at 1900 was higher than 280 ppm... so you are also using different base periods for your calculations of percentage increase of CO2 vs warming purportedly caused by this percentage increase. Finally: "...less than 1/3rd of the predicted amount, and that's only if you assume all the warming was from CO2 (highly unlikely)." The figure of 3C from a doubling of CO2 you cite is the amount climate science projects from CO2 and fast feedbacks not CO2 alone. If you correct for the host of errors identified above you will find that based on the increase of CO2 levels observed so far we'd expect, and have observed, temperature increases of about 0.8 C globally since CO2 rose above 280 ppm. In short, projections of 3 C warming are right on track... which is precisely why that IS the average projection... because it is what observations thus far suggest is most likely.
  8. Lindzen and Choi find low climate sensitivity
    @RW1: again, that has been debunked over and over again. First, most of the CO2 has been added to the atmosphere in the past 40 years. Second, it takes quite a while for the entire impact of CO2 to be felt, so some of that temperature increase is still "in the pipeline." Third, I don't believe you get 75% of the increase you'd get from doubling CO2 from a 35% increase in its concentration. I'd be curious to see where you got those figures - hope it's not from that same website. Fourth, the current temp increase is 0.8C, not 0.6C. "and that's only if you assume all the warming was from CO2 (highly unlikely)" CO2 + Feedbacks. It's not "highly unlikely", but rather very likely that the greater part of the warming is due to CO2 increase, and you have not provided any evidence to the contrary. "I've never seen the fundamental science, calculations and logic presented there adequately disputed anywhere." May I suggest that you actually look at peer-reviewed litterature rather than seeking confirmation for what you already believe from random web sites on the Internet?
  9. Lindzen and Choi find low climate sensitivity
    archiesteel (RE: Post 31), Just look at the icecore data from Vostok, for example. The amount of warming we've experienced in the last 100 years of about 0.6 degrees C is not only within the range of natural variability - it's below average. Over the last 10,000 years the average amount of temperature change per century is roughly 1 degree C - with some 100 year periods seeing as much as 2 degrees C:
  10. Lindzen and Choi find low climate sensitivity
    muoncounter (RE: Post 30), The biggest piece of contradictory evidence is that the amount of expected warming is absent. Due to the logarithmic response of CO2, an increase from 280 ppm to 380 ppm equals about 75-80% of the forcing from a doubling of CO2. 75% of 3 degrees C is 2.25 degrees C. During the period from about 1900-2000, the amount of warming was only about 0.6 C - less than 1/3rd of the predicted amount, and that's only if you assume all the warming was from CO2 (highly unlikely). They have tried, after the fact, to ascribe the lack of warming to be due to aerosols. Or is it ocean thermal inertia? Or something different tomorrow or next week? It seems anything but conclude the hypothesis is probably wrong, and the sensitivity is far smaller than they are still claiming it is. The scientific method dictates modifying or discarding a hypothesis when it does not fit the evidence. It does not permit adding unsubstantiated things arbitrarily after the fact when the hypothesis is not in accordance with the evidence. The site that was referenced and the empirically derived calculations of sensitivity by George White totally add up. I've never seen the fundamental science, calculations and logic presented there adequately disputed anywhere. If you believe you have clear evidence that contradicts it, present it in detail and we'll discuss and debate it.
  11. Lindzen and Choi find low climate sensitivity
    @RW1: "The burden of proof is not on the skeptics to demonstrate what caused the warming because the amount and rate of warming we've experienced is well within the range of natural variability." Wrong. The burden of proof *is* on the skeptics to prove that similar temperature increases have happened at this rate in the past, and that similar natural forces are at play today. There is no evidence of this, nor have you provided any. "The burden of proof is on the AGW proponents to demonstrate it was caused by CO2, and all of that evidence has to be in accordance with all other existing evidence." Wrong again. The burden of proof is on the AGW proponents to demonstrate it was caused by CO2, and all of that evidence has to be in accordance with all other existing evidence. The evidence is already there supporting AGW, if only in the satellite-measured OLR or ground-measured downward LR. In other words, all lines of evidence point to the warming being caused by CO2, while there is virtually no evidence supporting your position. "It only takes one piece of contradictory evidence to disprove a hypothesis - no matter how much confirming evidence may exist." As muoncounter said, please provide this evidence. After all, the burden of proof is on you, not on AGW proponents. AGW is the currently accepted science. The burden of proof is on the challengers.
  12. Debunking this skeptic myth is left as an exercise to the reader
    #50: "analyzing the attitudes behind denialism and the underlying mechanisms" Here's a relevant definition: denial /de·ni·al/ (dĭ-ni´il) in psychiatry, a defense mechanism in which the existence of unpleasant internal or external realities is kept out of conscious awareness. That's a fascinating area of study, but probably not what John had in mind for this discussion.
  13. Lindzen and Choi find low climate sensitivity
    #29: "It only takes one piece of contradictory evidence to disprove ... " Where is this piece of evidence? Love to see it. Let's review what we have seen: Begin with this quixotic statement: "... average global temperatures are actually colder at perihelion in January then at aphelion in July." Follow with some back-of-the-envelope-style calculations which some here have already called into question. Continue with the declarative judgment "response time is a non issue". Avoid all attempts to consider other SkS pages wherein these claims, many of which have been raised before, are addressed in detail. When asked for a reference, refer only to a website which concludes with the polemical ... CO2 mitigation will have no effect, other than to drag down the worlds economy and impede the goal of energy independence. A world economy, I might add (with a short veer off-topic), that was (and remains) perfectly capable of dragging itself down without any CO2 mitigation. And in rebuttal, present "... natural forces at work, the bulk of which we don't even know." No, sir, that's not evidence. And in this particular part of the blog-science world, this statement is indeed true: "basic fundamental scientific principles still apply."
  14. Lindzen and Choi find low climate sensitivity
    archiesteel (RE: Posts 27 & 28), The burden of proof is not on the skeptics to demonstrate what caused the warming because the amount and rate of warming we've experienced is well within the range of natural variability. The burden of proof is on the AGW proponents to demonstrate it was caused by CO2, and all of that evidence has to be in accordance with all other existing evidence. There can't be any significant discrepancies or inconsistencies, especially those which cannot be adequately explained in the overall context of the theory. It only takes one piece of contradictory evidence to disprove a hypothesis - no matter how much confirming evidence may exist. Now I know that climate is not an exact science, so there is some leeway; however, these basic fundamental scientific principles still apply. *And no - I'm not damorbel (whoever that is).
  15. Lindzen and Choi find low climate sensitivity
    @RW1: sure we can assume the warming is due to CO2, because there are no other causes that could be indentified. Of course, this means filtering out cyclical patterns, which is what climate scientists do. That said, if you want to chase for those elusive other causes, please do, and come back to us when you have actual evidence. In the meantime, we'll stick with the actual science.
  16. Lindzen and Choi find low climate sensitivity
    muoncounter (RE: Post 24), You can't assume all the increase in temperature we've seen is from additional CO2. The climate doesn't do anything but change. There are many natural forces at work, the bulk of which we don't even know.
  17. Hyperactive Hydrologist at 04:06 AM on 20 December 2010
    Stratospheric Cooling and Tropospheric Warming - Revised
    Just a quick question: The absorption band in figure 3 for 1000ppm of CO2 is only marginally wider than that for 100ppm of CO2. Is this an indication that subsequent increases in CO2 will have a lesser warming effect? And what is the relationship between CO2 concentrations and warming? Is it linear, logarithmic etc? Of course this question is related to the hypothetical planet with no other forcing in play.
  18. Lindzen and Choi find low climate sensitivity
    VeryTallGuy (RE: Post 22), 4 W/m^2 would the total that affects the surface only if all the absorbed power is directed back toward the surface, but only about half of it does because GHG infrared absorption and re-radiation is in all directions - i.e. about half goes down and other half goes up out to space in the same general direction it was already headed.
  19. Lindzen and Choi find low climate sensitivity
    How do these statements, taken together, make any sense? #16: "The albedo adjusted gain factor of about 1.6 ..." #19: "... is just an aggregate empirical measure of the system's response at the surface ..." #23: "... cumulative effect of all the feedbacks are already accounted for in the measured gain response of 1.6. This is why the total increase in temperature is greater" If gain=1.6 and gain is an 'aggregate empirical measure', then 23 is contradicted. If the total increase in temperature is greater than you predict (and it is), then either 16 or 19 are incorrect. It appears that your numbers put you in line with the "ultra-conservative unrealistic low climate sensitivity scenario", which is addressed in a very thorough treatment here.
  20. Philippe Chantreau at 02:55 AM on 20 December 2010
    The 2nd law of thermodynamics and the greenhouse effect
    "althought I feel free, I am not free.....if you see what I mean." I don't. It is clear that you are not free to accuse people of colluding to deceive, engaging in conspiracy, commiting fraud and a number of other things that are outlined in the comment policy. If you want to accuse scientists of fraud, you can go rant on CA or WUWT. I had a great many of my comments taken down on this site, I could always get a clue why they were. Get a grip. If you have something of substance to say on the mattter, say it. If it is not of substance, off topic, or belongs in the categories listed above, keep it to yourself
  21. Lindzen and Choi find low climate sensitivity
    Riccardo (RE: Post 21), The cumulative effect of all the feedbacks are already accounted for in the measured gain response of 1.6. This is why the total increase in temperature is greater than the intrinsic response.
  22. Lindzen and Choi find low climate sensitivity
    RW1 @9 The 4 W/m2 is total change in radiative forcing at the top of the atmosphere (TOA). 4W/m2 extra heat absorbed by the earth's system. That's the change in total heat balance at that point. You can't just halve it to suit your argument.
  23. Stratospheric Cooling and Tropospheric Warming - Revised
    RSVP #5,#29: The earth's surface receives energy from the sun at a certain rate. In the lower atmosphere, that energy is transported mainly by convection, but also by radiation. At higher elevations, radiation becomes more important. Because CO2 absorbs infrared in a wavelength range near the peak of the thermal emission, it reduces radiative transport of heat in the troposphere. The result of increasing CO2 is an imbalance: solar energy is still arriving, but it's not leaving as fast. So, the earth gradually heats up. However, as it heats up the earth radiates more. Eventually (if CO2 concentration stops increasing), the temperature rises enough that the heat loss rate matches the rate of heat received from the sun and the temperature stabilizes. That's what Bob Guercio is saying about the troposphere, though he gives more detail. There is no double counting.
  24. Stratospheric Cooling and Tropospheric Warming - Revised
    @ MarkR #26 By this time you should know that answering RSVP by constructing an example based in his/her 'logic' to show any inconsistency would have you -as if by magic- as the proposer of such inconsistent arguments. You should regard that comment #5 starts with an apparent connexion to the subject of the post. The not-possibly-multi-task packet is not in the post nor the idea it describes. It's something created as a particular person reads an article. @ RSVP What makes you think that the post is saying something like what you are describing in #5?
  25. Stratospheric Cooling and Tropospheric Warming - Revised
    RSVP "By double time, I am referring to a single packet of energy. If it gets into the air via CO2,(coming from a hot stone on the ground), the hot stone has just lost that heat. That is not double time. That is heat transfer." CO2 is no different to a hot stone. The stone is continually receiving packets of energy (during the day), as would the CO2. They both emit at the same time as absorbing, largely because they consist of billions of molecules at different states of excitation at any point in time. They are both 'double timing'.
  26. Stratospheric Cooling and Tropospheric Warming - Revised
    Hi Bob@28. Copyright is a complicated issue. Generally it is best to assume you can't use something unless it is stated you can. On the other hand, if someone wants to 'prosecute' to protect their copyright, it usually is a civil action, not a criminal one. Which means that the person/organisation who is protecting their copyright has to have the money to take legal action (they won't have state aid, criminal prosecutions are usually by the state). But then again, there are fare use exceptions in the US. In many places, if something is used in schools or colleges or in not for profit situations, then the owner may allow the use of the materials, but they usually state that the materials can be used in those situations. You put a copyright notification on your own article, that implies you don't want anyone to copy it without you giving permission. BTW by default every piece of work is copyrighted, I don't believe the notice is required other a reminder to the reader. Creative Commons licensing is a great new way of dealing with this sort of issue. The licenses allow as much or as little flexibility as you want.
  27. Debunking this skeptic myth is left as an exercise to the reader
    Speaking of The Hollow Earth, perhaps the warming comes from the internal sun becoming a red giant in spite of its size :) The fact is we live in times when epistemological hedonism[1] is king so any book describing global warming as a hoax will reach larger publics the same way Velikowsky's or Von Däniken's books would sell copies ten times the best selling book devoted to debunk their theories. And in a similar way, Watts' paraphernalia gets 2 million hits a month, while RealClimate gets 360K and this site 220K[2]. People has been swollen by this tide of epistemological hedonism and -placing their necessities, including that of recognition, above everything else- they simply write to the head of a website to share the preposterous theory they took a fancy to. The same about some people commenting and the dumbpiphanies they sometimes provoke. I wonder if analyzing the attitudes behind denialism and the underlying mechanisms is not as important as spreading good science about what causes global warming causes and discussing solutions. [1] THE LIMITS OF CRITICAL THINKING by Jamy Ian Swiss Swift 1-1, page 14 [2] Wattsupwiththat; RealClimate; SkepticalScience
  28. Stratospheric Cooling and Tropospheric Warming - Revised
    MarkR #26 "By increasing the temperature of the atmosphere, you increase the amount of heat that it radiates " The increase came from the thing you now say it is heating. "It does 'double time' because it's constantly receiving heat " By double time, I am referring to a single packet of energy. If it gets into the air via CO2,(coming from a hot stone on the ground), the hot stone has just lost that heat. That is not double time. That is heat transfer.
  29. Stratospheric Cooling and Tropospheric Warming - Revised
    The Ville -25 What are the rules for using online images? If I see an image that I like, how do I know whether or not I'm allowed to use it? Thank you, Bob
  30. Renewable Baseload Energy
    Actually thoughtful, You pump the water out one well, use the heat/cool and then pump the water down the other well. Since it is a siphon energy use is minimal. There is no net use of water for heat/cool. I get the impression this type of heat pump in only useful where there is a lot of water (like here in Florida).
  31. Stratospheric Cooling and Tropospheric Warming - Revised
    #5 RSVP: Increasing the kinetic energy of a system isn't necessarily work. Imagining a closed, fixed piston, you can put in heat through the walls that will increase the kinetic energy of the molecules without doing work. Work is done in an ideal gas by expansion. The tropopause has risen, so the troposphere has expanded, but unless it expands forever then it is not constantly doing work and therefore the flow of energy must be heat. It does 'double time' because it's constantly receiving heat so it has to 'dump it'. Some light heats the molecules, they bump around warming other things which allows the heat to be dumped so that more IR can be absorbed. If it didn't do this, it would just increase in temperature forever and quantum physics/thermodynamics would be broken!
  32. Stratospheric Cooling and Tropospheric Warming - Revised
    #5 RSVP: By increasing the temperature of the atmosphere, you increase the amount of heat that it radiates and this can be approximated by Planck's law with a wavelength dependent emissivity plugged onto the end. To an individual molecule acting electromagnetically, there is no 'up' or 'down', all direction are equal. Therefore it will radiate in all directions. CO2 absorbs IR light and transfers much of this to surrounding molecules in kinetic energy (and at the same time collisions will pump energy back into the CO2, such that the output looks more like a greybody). All of these molecules will couple to the vacuum field and decay to lower energy states, emitting light. Warmer temperatures mean more light, and more light going down heats the surface. This is the basic pure radiative effect. There are other complicating factors, but this is the most important. It explains why there is so much longwave radiation coming down to Earth.
  33. Stratospheric Cooling and Tropospheric Warming - Revised
    Bob love the diagrams, it is clear you spent a lot of time on this. Not sure the 'step 2' diagram works?? My interpretation of that is some sort of fission explosion! I guess without animation it's difficult to show a collision.
    Response: [from John Cook] That's my fault, I offered to do the diagrams for Bob. Wasn't sure of a good way to portray two molecules colliding - welcome any suggestion of a better version (eg - a link to an image online).
  34. Lindzen and Choi find low climate sensitivity
    RW1 the often quoted 4 W/m2 is the imbalance at TOA, i.e. the amount of energy not allowed to leave the planet after a doubling of CO2. Following your scheme, an equal amount is radiated back to the surface. In this way you get a 1.2 K increase in temperature; incidentally, this is equal to the so-called Plank sensitivity. To know the equilibrium temperature increase you still need to multiply it by the feedback factor, which is not included in the 4 W/m2.
  35. Lindzen and Choi find low climate sensitivity
    @RW1: that site (www.palisad.com) doesn't seem very credible. The best analogy that has been given is the tub filling in vs. ripples. Seasonal variations tend to cancel out over time, while the current warming we are seeing keeps going up. The whole isn't in AGW theory, it's in your understanding of the theory.
  36. The human fingerprint in the seasons
    @Argus: "I also read about severe problems with snow in Canada some of weeks ago." Actually, our winter is quite typical, even a bit on the mild side. Europe does seem to be getting colder, but remember we're talking about Global, not European temperatures.
  37. Lindzen and Choi find low climate sensitivity
    muoncounter (RE: post 18), Yes, the oceans have thermal inertia, as evidenced by the roughly one month of "seasonal lag", but the overall response is still relatively fast in each hemisphere every year. This contradicts the ocean thermal inertial taking decades to fully respond. The albedo adjusted gain is just an aggregate empirical measure of the system's response at the surface to incoming power from the Sun. As you can see from that site, it varies a little but is roughly about 1.6 on average.
  38. Lindzen and Choi find low climate sensitivity
    #17: The two paragraphs in your comment don't seem to have any logical connection. Don't the oceans have thermal inertia? Is there any research regarding 'albedo adjusted gain', beyond this website?
  39. Stratospheric Cooling and Tropospheric Warming - Revised
    "You're serious, aren't you ? Can't you see the connection between air getting hotter ergo surface (land or ocean) getting hotter ?" In RSVP's world, if you lie on the ground at Death Valley you'll be just as cold as if you'd laid on the ground in the high desert ...
  40. Lindzen and Choi find low climate sensitivity
    Riccardo (RE: Post 15) The hemispheric seasonal responses to large changes in radiative forcing are relatively quick – certainly not years or decades. If they were, we wouldn't see anywhere near the seasonal variability throughout each year. There is a delay or "seasonal lag", but it’s only about one month. This contradicts the notion that a tiny increase in radiative forcing of less than 2 W/m^2 from a doubling of CO2 gradually added to atmosphere over decades will take decades longer after to reach equilibrium. If anything, because CO2 is added incrementally and so slowly over such a long period of time, the response time is a non issue.
  41. actually thoughtful at 13:48 PM on 19 December 2010
    Renewable Baseload Energy
    Michael - fantastic. It occurs to me that you are concentrating the value you get from your well - which is a good thing. Unless the well goes dry - in which case you wake up with no water and no heat/cool. Actually, I think you will still get heat/cool, even from a dry well (better performance with the water of course).
  42. Lindzen and Choi find low climate sensitivity
    Riccardo (RE: Post 15), How am I confusing the surface and the TOA? Are you saying that power from the Sun and additional power redirected from CO2 are not both "forcing" the surface? The energy balance is determined by the rate at which incoming power from the Sun is allowed to leave the planet (at the TOA): The incoming short wave infrared energy from the Sun is mostly transparent to the clear sky atmosphere. Cloudy sky is obviously different, as a lot of the energy is reflected off of and absorbed by the clouds - a much smaller amount makes it through. The short wave energy that hits the surface is re-radiated back up in the form of long wave infrared, which in certain wavelengths is absorbed and re-radiated by greenhouse gases and/or clouds. In effect, the presence of greenhouse gases and clouds delay the release of infrared heat energy by redirecting some of it back toward the surface, which makes the surface warmer than it would be otherwise. The albedo adjusted gain factor of about 1.6 means that due to the greenhouse effect, it takes about 1.6 W/m^2 of power at the surface for each 1 W/m^2 of power to leave the system, offsetting each 1 W/m^2 entering the system from the Sun. In other words, power in = power out. The albedo adjusted solar input of about 238 W/m^2 = 238 W/m^2 leaving the planet, and a power of 238 W/m^2 equates to a temperature of about 255K, which is the so-called effective temperature of the earth as seen from space. There is no difference between power sourced from the Sun and additional power re-directed back to the surface as a result of more CO2 being added to the atmosphere. Afterall, a watt/meter squared of energy and power is watt/meter squared of energy and power, independent of where it originates from. Put another way, the surface doesn't "know the difference" between heat or power sourced from the Sun or additional heat or power re-directed back down from GHGs and/or clouds - all it "knows" is what the total heat and power is at the surface; and the total power at the surface in W/m^2 is directly tied to temperature via Stefan-Boltzman because the surface of the earth is considered to be very close to a perfect black body radiator. At an average global temperature of 288K, the surface emits 390 W/m^2 of power. About 240 W/m^2 of this is from the Sun and the additional 150 W/m^2 is from GHGs and clouds in the atmosphere re-directing infrared power back down toward the surface. If the albedo adjusted power from the sun increases 2 W/m^2, the infrared power at the surface increases 2 W/m^2, plus about an additional 1.2 W/m^2 will be redirected back downward from the atmosphere (due to the presence of GHGs and clouds) for net increase of about 3.2 W/m^2 - raising the surface power total to about 393.2 W/m^2 (or a temperature of 288.6K). If instead, the albedo adjusted power from the Sun is unchanged, but an additional 2 W/m^2 of infrared power is redirected downward to the surface as a result of a doubling of CO2, the most additional power that can amplify (or in effect re-redirect down) the added 2 W/m^2 is only about the same 1.2 W/m^2 because there is no physical or logical reason why an additional 2 W/m^2 of infrared power at the surface will behave radically different from either the original 99+% or an additional 2 W/m^2 from the Sun.
  43. Stratospheric Cooling and Tropospheric Warming - Revised
    Thank you, Tom Curtis and Joe Blog. I'm impressed by the fundamental science that people on this blog know.
  44. Stratospheric Cooling and Tropospheric Warming - Revised
    But through O2/O3 UV absorption...
  45. A detailed look at climate sensitivity
    To RW1 on the Lindzen thread, muoncounter recommended that you visit this thread for evidence of high sensitivity. I second that, but IMO the arguments here come up short in several respects. One is that the average measurement of higher water vapor do not take into account the distribution of WV. If it is higher and evenly distributed then it is a positive feedback to CO2 warming. But if WV is unevenly distributed in a world warmed slightly by CO2, then an average increase in WV will result in less or no amplification. Second, the derivation of sensitivity from paleo studies routinely ignores unmeasured confounding factors. I gave one possibility here: cosmic-rays-and-global-warming.htm but there are others. Typically the response is to treat solar geomagnetic variations as a proxy for TSI and then dismiss it because of poor correlation and low amounts of TSI change. Also the last 30 years of detailed measurements don't show much in the way of GCR related climate effects. However the penultimate interglacial coincides with an abrupt decline in GCR so a relatively small TSI increase could be amplified without the need for CO2 feedback.
  46. Stratospheric Cooling and Tropospheric Warming - Revised
    oamoe at 12:30 PM Because the stratosphere isnt really warmed by terrestrial LW absorption. But through UV O2/O3 absorption, terrestrial LW does off set loses somewhat, but CO2 is emitting just under twice what it absorbs in the stratosphere. Its a Q of path length, how opaque the atmosphere is to what wavelength. At the tropopause the path length in 15micron is already short enough that it basically just acts to transmit energy. This is a result of the reducing pressure, so for a given area(volume) there are less molecules than at a higher pressure.
  47. Stratospheric Cooling and Tropospheric Warming - Revised
    Let me ask my previous question in a different way, why does the absorption of IR in the troposphere not dominate as the major cause of the cooling of the stratosphere. It seems odd that collisional activation of IR emission by CO2 would be so important.
  48. Lindzen and Choi find low climate sensitivity
    RW1 there are a few pieces that got to be fixed. "All I did was apply the same gain factor for solar power to additional power from CO2." You did it wrong as I explained in my previous post, you're confusing surface and TOA. "Ultimately, what matters is the total infrared power at the surface" The energy balance of the planet is governed by what happen at TOA, not at the surface. What we see (measure) at the surface is the effect of the change at TOA. "The point I was making about the perihelion power increase of about 14 W/m^2 was that a much larger increase in radiative forcing above the average doesn't have anywhere near the proportionally predicted effect as the AGW warming theory says will happen with just a 2 W/m^2 increase in radiative forcing from a doubling of CO2." (emph. mine) You should not expect any proportionality, indeed. When you have a cyclic forcing, the effect depends of the response time of the system. If the response is slow you won't get the full effect of the forcing; you are comparing a forcing with a one year period with a response time of the order of decades. An extreme example is the diurnal cycle, where you have the forcing going from about 240 W/m2 to zero but the temperature doesn't change proportionally.
  49. Lindzen and Choi find low climate sensitivity
    I'm asking the question because I think it's a significant hole in the AGW theory that I've yet to see adequately explained. What I'm trying to show is that the CO2 AGW theory is saying that the climate system is all of the sudden going to treat an additional 2 W/m^2 of power at the surface radically different than it does the original existing 99+ percent, and while I suppose that is theoretically possible, there is no physical, empirical or logical reason why it would, especially in a system that is constantly changing everywhere, by relatively large magnitude. Ultimately, what matters is the total infrared power at the surface, independent of where all the power orginates from - the the Sun, GHGs and/or clouds. Both 2 W/m^2 of additional infrared power from the Sun "forcing" the surface and 2 W/m^2 of additional infrared power from CO2 "forcing" the surface are the same - all the surface 'knows' is what the total power is, and the total power is directly tied to temperature via Stefan-Boltzman (*if this was not true, then power from the Sun and additional power from CO2 cannot both be expressed in W/m^2 as they are). The point I was making about the perihelion power increase of about 14 W/m^2 was that a much larger increase in radiative forcing above the average doesn't have anywhere near the proportionally predicted effect as the AGW warming theory says will happen with just a 2 W/m^2 increase in radiative forcing from a doubling of CO2. Now of course one can always say that it will be the 2 W/m^2 increase above the total cumulative average that will cause a much larger amount of warming by suddenly triggering very large positive feedbacks (that don't happen to exist or act on the original 99+%), but there really isn't any physical, logical, or empirical basis for that, especially given the total amount of radiative forcing is constantly changing spatially and in time...all the time (warming, cooling, etc). If the climate as a whole was a steady state and static system, it might be more plausible, but the climate system is incredibly dynamic instead. That the global climate doesn't even appear to be phased by a 14 W/m^2 increase in radiative forcing, suggests the net feedback operating on the system as a whole is strongly negative - not positive, and the tiny increase of only about 2 W/m^2 from a doubling of CO2 will be - if not infinitesimal, benignly small.
  50. Lindzen and Choi find low climate sensitivity
    Riccardo (RE: Post 12), All I did was apply the same gain factor for solar power to additional power from CO2.

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