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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 101401 to 101450:

  1. An Even Cloudier Outlook for Low Climate Sensitivity
    "There is something here for a lot of people to learn from. Admittedly I'm finding it difficult to find information to look into this. Would anyone here be able to explain how Andy came to 20W/M*2." GO ASK HIM AT REAL CLIMATE. C'mon people, are you afraid that your debunkers might not really be debunking anything at all? "In our present climate, the reflection of solar energy back to space dominates, and the net effect of clouds is to reduce the net flux of incoming energy at the top of the atmosphere (TOA) by ~20W/m*2, as compared to an otherwise identical planet without clouds." If this were known to be true, then the net feedback from clouds wouldn't be the big mystery it is acknowledged to be, would it?
  2. An Even Cloudier Outlook for Low Climate Sensitivity
    On another site we are discussing Andy Desslers paper. A rather sharp guy CBACBA is challenging where Andy gets his number for this below. ##################################################################### In our present climate, the reflection of solar energy back to space dominates, and the net effect of clouds is to reduce the net flux of incoming energy at the top of the atmosphere (TOA) by ~20W/m*2, as compared to an otherwise identical planet without clouds. ###################################################################### There is something here for a lot of people to learn from. Admittedly I'm finding it difficult to find information to look into this. Would anyone here be able to explain how Andy came to 20W/M*2. How does the net effect of clouds reduce the net flux of incoming energy at the top of the atmosphere by 20w/m*2, as compared to an otherwise identical planet without clouds?
  3. The 2nd law of thermodynamics and the greenhouse effect
    This discussion would manage a great deal less misinterpretation if using an agreed text book on thermodynamics which includes the rigorous mathematical development. Then can be on "same page" as it were. What is you suggested reference damorbel?
  4. Extreme weather isn't caused by global warming
    From 2010 - Global temperature and Europe's Frigid Air: We live in a world of contrasts gone wild. In producing this map the radius of influence of a given station is limited to 250 km to allow extreme temperature anomalies to be apparent. Northern Europe had negative anomalies of more than 4°C, while the Hudson Bay region of Canada had monthly mean anomalies greater than +10°C.
  5. An Even Cloudier Outlook for Low Climate Sensitivity
    MarkR, thanks for pointing out the broken link. Hopefully this will work http://gmao.gsfc.nasa.gov/pubs/docs/Rienecker369.pdf otherwise cut and paste http://gmao.gsfc.nasa.gov/pubs/docs/Rienecker369.pdf into your browser. This technical report is really quite good and it does list what observation data is assimilated into the model. It does not appear to include SAR data or any other terrestrial data, I assume it was created specifically for satellite data assimilation.
  6. The Scientific Guide to Global Warming Skepticism
    #41: The map in that page is stunning and well worth showing, but I will put it in the 'extreme weather' thread.
  7. The 2nd law of thermodynamics and the greenhouse effect
    Re #162 Riccardo you wrote :- "honestly I find it and the discussion on the caloric theory really pedantic." Um, well, yes; very interesting. Tell me do you also reject the conclusions that have been drawn in consequence of the failure of the 'caloric theory' to match scientific observations, such as the 1st law of thermodynamics, the conservation of energy etc.? You wrote also :- "You confuse heat and internal energy. Here's the first quote I found just googling, but I urge you to check in a standard textbook:" In #160 I was drawing a distinction between internal energy which causes a temperature change (heat) and internal energy that doesn't cause a temperature change, sometime (mistakenly) called 'latent' heat. How do you draw a distiction between the two? I have seen the sort of 'stuff' in the link you give and I often wonder how the idea came about. Of course latent heat is not the only manifestation of the inadequacy of the definition in your link. What about gases with different specific heats? Equal molar quantities of He, O2 and CO2 at the same temperature possess completely different amounts of thermal energy, can you say what their temperatures would be if they had the same (molar) internal energy?
  8. How climate skeptics mislead
    > I'll never believe a word based solely on the fact it > appeared in a peer reviewed paper Wise; that's only the beginning; then look for citing papers and followup work, which always come along if the idea is interesting > until I understand it properly What if you can't? Are you as smart and well educated as _every_ publishing scientist in every field? > and I think you'd better do the same "... everybody was finally equal. They weren't only equal before God and the law. They were equal every which way. Nobody was smarter than anybody else. ...." http://www.tnellen.com/cybereng/harrison.html
  9. The Scientific Guide to Global Warming Skepticism
    NASA GISS has a new page about the record high November global temperature and cold weather anomaly in Europe. 2010 - Global Temperature and Europe's Frigid Air
    Moderator Response: Fixed broken link
  10. An Even Cloudier Outlook for Low Climate Sensitivity
    Eric, your first link is broken! I'm not familiar with data used here, but ECMWF reanalyses are extensively validated and generally speaking the use of AGCMs isn't a problem since the sets feature regular data assimilation which prevents drift and includes the effect of coupled changes. If you have the time to delve further then I'm sure there will be plenty of papers discussing validation and testing. There are some problems with certain sets (e.g. ERA40 snow mass) but in that case at least the reasons are well known and publicised. I'm not sure what you mean by no observations of wind: iirc synthetic aperture radar observations are regularly assimilated and they can give good estimates for wind speed over oceans...
  11. Stratospheric Cooling and Tropospheric Warming
    Guten Tag Ebel, aber, mein Deutch ist nicht sehr gut. :-)
  12. Stratospheric Cooling and Tropospheric Warming
    Mars, Joe, and TallGuy, The environmental lapse rate is not the same as the adiabatic lapse rate. There are other factors at work; one of them is the loss of energy through radiation. My take is that stratospheric cooling has two components: less radiation getting out from the troposphere and greater ability to radiate LW. The less radiation leaving bit is only until a new, higher point of equilibrium is reached. One thing I'd like to mention is that the leveling off to a new equilibrium temperature will not even start until after CO2 levels are stabilized. The leveling off of CO2 is not guaranteed to remain within our ability to affect depending on how the feedbacks play out.
  13. It's not us
    #10: "located at the upper reaches of the troposphere." That seems unlikely as the increasing concentrations are measured at surface stations with a wide variety of elevations, notably Mauna Loa at 3400 m. But it would be helpful to know where you read that, because I've seen everything from 'they are well-mixed' to 'they are at highest concentrations near the surface'.
  14. The 2nd law of thermodynamics and the greenhouse effect
    damorbel "So first off heat doesn't flow'; only fluids flow" honestly I find it and the discussion on the caloric theory really pedantic. You confuse heat and internal energy. Here's the first quote I found just googling, but I urge you to check in a standard textbook:
    "Heat may be defined as energy in transit from a high temperature object to a lower temperature object. An object does not possess "heat"; the appropriate term for the microscopic energy in an object is internal energy."
  15. How do we know CO2 is causing warming?
    VTG - I disagree based on the papers listed in the articles. Taking say the Philipona/Evans approach, you MEASURE the DLR amplitude and spectrum. To compute what it "should" be (model result), then calculate from radiative transfer equations (Ramanathan and Coatley 1978 for the maths). This is a very different calculation from the demonised GCMs - no dynamic component and insensitive to minor variations so you dont need minutely accurate picture of atmosphere for clear-sky calculation. Not only does the calculation match measurement for amplitude and spectrum, but it is very hard to see how you could obtain that measurement without the CO2 greenhouse effect. Can do essentially the same at the TOA. This doesnt tell you all about surface heating but it does tell what the radiative heating due to CO2 is. To argue about AGW, you need to look at other factors and feedbacks but I'd need a convincing explanation of those measurements from another theory to doubt the radiative component of CO2.
  16. The 2nd law of thermodynamics and the greenhouse effect
    Re #160 - should have been "Re #159 Philippe Chantreau"
  17. The 2nd law of thermodynamics and the greenhouse effect
    Re #153 Philippe Chantreau you wrote:- " confused between heat (in thermodynamics, that means net heat flow) and energy (which can be almost anything). Heat must comply with the 3 laws. Energy can flow ." I hope I have a good grasp of your meaning because I do think you have a good understanding of the matter. Please do not think I am just being pedantic because all matters in thermodynamics and energy are closely related therefore words must be used with a precise meaning. So first off heat doesn't flow'; only fluids flow. This was the failure of the old caloric theory; caloric was supposed to be a fluid 'filling in the spaces' between the atoms and giving it the feeling of hotness. This theory came into question when it was realised that the friction involved in boring out a cannon barrel that caused it to get hotter; the temperature rise could be directly related to the (frictional) work done. Also hotter material weighed no more than when it was cold. At the time this was powerful evidence because Lavoisier had used a similar technique to disprove the phlogiston theory of combustion. A second, more modern, confusion; the one about heat meaning 'net heat flow'; a sort of term for energy 'in transit' (somehow). Let there be no doubt about it, heat is energy density where the energy is in the form of molecular motion, it is to be found in all materials above 0K. This energy density is the material's temperature, it is only related to energy by dividing the energy by the material's specific heat K = Q/C. As you say just saying 'energy' is far too vague, e.g. for mixtures of steam and water; water contains a lot of none-thermal energy in the binding force that make its molecules a liquid - this is the energy also called the latent heat of evaporation. But the binding force has got nothing to do with molecular motion, even though the energy it implies can only be overcome by molecular motion. In regard to this last matter, the heat of a water/steam continuum dose not increase as the % steam increases because the temperature doesn't change, only the energy in the system increases. That is why a water/steam mixture can be at equilibrium i.e. the temperature in the liquid is the same as the steam, so no energy transfer (no change in entropy).
  18. An Even Cloudier Outlook for Low Climate Sensitivity
    Maybe Dr. Dessler would be kind enough to also answer questions here? Other prominent and respected climate scientists (including Trenberth and Soden) agree that Dr. Dessler's methodology is sound. Certainly much more sound that that used by Lindzen and Choi (2009). From ClimateProgress: "This is a very important check of the models,” says climate researcher Qiang Fu of the University of Washington, Seattle. “It shows no evidence of a large negative cloud feedback.” But climate researcher Roy Spencer of the University of Alabama, Huntsville, disagrees. He published one of the two papers finding evidence of a strongly negative cloud feedback. He finds in his own analyses signs that Dessler is seeing not only cloud changes caused by temperature changes but also temperature changes caused by natural cloud fluctuations. Such effects garble the true negative feedback beyond recognition, he says. Spencer’s “interpretation is wrong," says Soden, but even if Spencer were right that there’s a cause-and-effect problem, Dessler’s method of comparing observations and models "eliminates some possibilities, such as the models being egregiously wrong. It’s about as good as we can do with current data sets." Also, "Dr. Kevin Trenberth, head of the Climate Analysis Section at the National Center for Atmospheric Research, is one of the leading experts on cloud modeling. He had been critical of some recent studies on the cloud feedback effect, so I asked for his thoughts on this study. He replied: "The work is sound and is a very useful contribution. It is a foil to some of the misleading work that Richard Lindzen has published (and which we have shown is wrong). Kudos to Andy Dessler for trying to do this and doing it as well as it can be done." Those are some pretty glowing reviews from some very critical and discerning climate scientists. Trenberth in particular, is a stickler for details, so his support of Dessler is important.
  19. Stratospheric Cooling and Tropospheric Warming
    No saturation. Es ergibt sich folgende Kurzdarstellung des Treibhauseffektes in 5 Punkten: 1. Die Atmosphäre ist im Wesentlichen zweigeteilt: unten die konvektionsreiche Troposphäre, in der das Wetter ist und wo wir leben und oben die konvektionsarme Stratotosphäre, wobei sich die Grenze zwischen beiden Sphären verschieben kann. 2. Der Temperaturgradient in der Troposphäre ist (fast) konstant - auch wenn sich die Dicke der Troposphäre ändert. Diese Konstanz ist konvektionsbedingt. 3. Die fast konstante optische Dicke einer sich ändernden Stratosphäre. Diese Konstanz ist strahlungsbedingt und ergibt sich aus der Skalierung (Maßstabsänderung) der Strahlungstransportgleichung bei Änderung der optischen Dicke bei Konzentrationsänderung des CO2. 4. Wenn der Temperaturgradient einen bestimmten Grenzwert überschreitet kann die Luftschichtung nicht ruhig bleiben und wird instabil = Konvektion = Kennzeichen der Troposphäre 5. Im stationären Zustand (d.h. auch wenn Zeit vergeht, ändert sich der Zustand nicht) ist im Mittel die Wärmeabgabe der Erde genau so groß wie die Wärmeabsorption - andernfalls müßten sich die Temperaturen laufend ändern. Das aber widerspräche der Stationarität. Diese 5 Punkte liefern eine Grundsensitivität der durchschnittlichen Oberflächentemperatur als Folge von Konzentrationsänderungen des CO2. Ergänzung: Die dickere Tropopsphäre hat eine größere Temperaturdiffernz zwischen oben und unten, wobei diese größere Temperaturdifferenz sich als Abkühlung oben und Erwärmung unten so verteilt, daß die Gesamtabstrahlung der Erde gleich der Gesamtabsorption ist. MfG
  20. An Even Cloudier Outlook for Low Climate Sensitivity
    Thanks Bodo. The study says nothing about 1.64 sensitivity. I suspect the article in question is taking this statement: "Indeed, our results suggest a global warming of 1.94°C in the RP‐case [baseline] versus 4.5°C by Betts et al. [1997] and 2.6°C by Levis et al. [2000]." and then subtracting 0.3°C from it. Which of course would make no sense whatsoever, because the 0.3 is incorporated into the 1.94. 1.94°C sensitivity for 2xCO2 would be low, but not unreasonable (the study also suggests that a lower climate sensitivity model may be realistic, which is how they get to that 1.94 with just a 0.3°C cooling effect). But the Register article is not surprisingly just riddled with errors. And like Daniel Bailey (#21) from what I've read, the results of this study are rather questionable.
  21. An Even Cloudier Outlook for Low Climate Sensitivity
    dhogaza, I've never been censored here in any way, nor subjected to any ad homs, so I prefer to ask my questions here. Someone here will point out my flaws soon enough.
  22. An Even Cloudier Outlook for Low Climate Sensitivity
    Eric@16: Thank you for posting this. You beat me too it. There are methodology problems with Dr. Dressle's paper.
  23. Ice data made cooler
    michael sweet #39 It's not clear where you are trying to go with this. Is it just all about negating anything I could possibly post? I assume some oxygen would be released. Why dont you simply quantify the amount or explain how oxygen and nitrogen are somehow exceptions to Henrys Law, or in which ways CO2 is special etc. Wouldnt this be good for everyone to know?
  24. It's not us
    I read that most of the CO2 from fuel emissions is located at the upper reaches of the troposphere. Is that true? If it is true, how can claims be made that the extra CO2 is causing faster plant growth? thanks if you have any links for this. Gail
  25. An Even Cloudier Outlook for Low Climate Sensitivity
    A quick perusal of the Bounoua et al study suggests they base much of their reductions of global temps by vegetation on an increase in evapotranspiration. However, recent evidence indicates a decline in the global land evapotranspiration trend due to limited moisture supply. Add in Dai et al 2010 and you have a recipe to cast into doubt much of Bounoua et al's primary hypothesis. This person's quick two cents (further reading required), The Yooper
  26. An Even Cloudier Outlook for Low Climate Sensitivity
    @dana1981: I uploaded the paper, here is it: http://rapidshare.com/files/436512358/2010GL045338.pdf
  27. An Even Cloudier Outlook for Low Climate Sensitivity
    "How you get from 0.3°C cooling to 1.64°C sensitivity is beyond me, unless it's mentioned somewhere in the study." You start with a GCM that gives 1.94C sensitivity, i.e. pick a low outlier and subtract 0.3C from that.
  28. An Even Cloudier Outlook for Low Climate Sensitivity
    Eric (skeptic) - if you're serious about debunking Dessler's paper, you should engage him directly at Real Climate, where he's posted and is participating in the resulting thread. If you've demolished it as thoroughly as you have apparently done, I'm sure you'll have no problem convincing him ...
  29. The Scientific Guide to Global Warming Skepticism
    Why climate change is a big freaking deal! “Climate Scientist Warns World of Widespread Suffering If Further Climate Change Is Not Forestalled” “ScienceDaily (Dec. 8, 2010) — One of the world's foremost experts on climate change is warning that if humans don't moderate their use of fossil fuels, there is a real possibility that we will face the environmental, societal and economic consequences of climate change faster than we can adapt to them.” http://www.sciencedaily.com/releases/2010/12/101208125801.htm In this case, the foremost expert is Lonnie Thompson, distinguished university professor in the School of Earth Sciences at Ohio State University. Kudos to Dr. Thompson for telling it like it is!
  30. An Even Cloudier Outlook for Low Climate Sensitivity
    pdt #15 - I saw that article too but I have no idea where they get 1.64°C for 2xCO2, unless it's mentioned somewhere in the study (which I don't have access to). In the abstract it specifically states that their findings mean there is a 0.3°C cooling effect globally for 2xCO2 which is not accounted for. How you get from 0.3°C cooling to 1.64°C sensitivity is beyond me, unless it's mentioned somewhere in the study. There's at least one error in the article, as it says the change over land is 0.3°C when it's actually 0.6°C. So I suspect they got the 1.64°C sensitivity wrong too. Perhaps somebody could link the whole paper, but here's the abstract. http://www.agu.org/journals/ABS/2010/2010GL045338.shtml
  31. Ice age predicted in the 70s
    "In Search Of"? Seriously? (-chuckles aloud-) BP, you missed your calling in life. (Guilty pleasures admission: the episodes on Mars dying from climate change [Season 1, Episode 9] and on the search for Atlantis [Season 1, Episode 10] are my favorites) For all you Leonard Nimoy fans (and you know who you are): Thanks for the chuckle, The Yooper
  32. An Even Cloudier Outlook for Low Climate Sensitivity
    I was interested in how Dessler calculated ΔRcloud in the first chart (the second is from various models). It turns out that the first chart is also from a model, documented in this tech report: http://gmao.gsfc.nasa.gov/http://gmao.gsfc.nasa.gov/pubs/docs/Rienecker369.pdf The essential difference between the model used for the first chart and those used for the second is that the former is a AGCM which can only do short term predictions since it doesn't model longer term changes in ocean circulations. The latter are GCMs. As explained in the link above, they match model results from the AGCM to the satellite observations using a gradient descent with the control variables listed on page 19. They adjust those control variables in the various equations that drive the AGCM. For example the water content control variable affects the scattering albedo in both the shortwave and longwave equations. I think the primary problem with this approach is that some variables are controlled coarsely and not observed. A good example is wind which can only be indirectly validated by the match of other model parameters. But there are multiple solutions to the control variables to obtain the match from model to observations. "with four parameters I can fit an elephant and with five I can make him wiggle his trunk" http://mahalanobis.twoday.net/stories/264091/
  33. An Even Cloudier Outlook for Low Climate Sensitivity
    Sorry if this is too far off topic, but I saw this article about climate feedback resulting in only 1.6C warming recently and thought it might be worthy of discussion. I have not read the scientific paper, but the linked article reporting on the results of the paper is typical of skeptic journalism, reporting one result and ignoring all other evidence. That particular journalist (and as far as I can tell "The Register" as a whole) only publishes skeptic articles.
  34. Ice age predicted in the 70s
    By whom? Popular daily newspapers & weeky magazines, e.g. Newsweek, are not reliable communicators of the accumulated scientific knowledge.
  35. Greenland has only lost a tiny fraction of its ice mass
    #7: "Greenland has had green growing plants on it at least twice during the time covered by our ice cores." I'm not sure where you think that 'discovery' goes. The interglacials did indeed allow plant growth. This ice-core temperature graphic gets posted a lot. Are you suggesting that the existence of relatively warm interglacials over the past few hundred thousand years somehow invalidates GHG-induced warming in the present? That will take some significant work on your part to substantiate; you might want to look here before trying to climb that mountain. There is even some evidence of plant growth on debris-covered glaciers. We find that alpine taxa can grow considerably below their usual altitudinal niche due to the cooler subsurface soil temperatures found on glacial debris with ice underneath and that may have significantly altered the spatial distribution of such flora during full glacial conditions.
  36. Philippe Chantreau at 02:17 AM on 13 December 2010
    The 2nd law of thermodynamics and the greenhouse effect
    Damorbel, I'm not saying that, Michele is. I know that these plants work, as I indicated. Johnson, according to Michele, says that "no energy" (that includes any and all) "can flow from a cooler object to a warmer one"; it means that no energy can flow from the colder individual mirrors to the hot concentrator. This is obviously false. I have not read the Johnson paper, I am just reflecting on the statement attributed to him by Michele. Awol, it seems there may be some confusion in how you consider your thermodynamics. If you accept that there is downwelling radiation (which you do), then you must also accept that the energy content of the surface increases as a result of that radiation. Whether it can be "directly measured" or not is irrelevant. And it does not mean that the direction of the net heat flow is going to change at any time. Everyone carrying on with the G&T stuff on the internet seems confused between heat (in thermodynamics, that means net heat flow) and energy (which can be almost anything). Heat must comply with the 3 laws. Energy can flow in a variety of ways, so long as the net heat flow of the system complies with thermodynamics.
  37. Hyperactive Hydrologist at 02:11 AM on 13 December 2010
    An Even Cloudier Outlook for Low Climate Sensitivity
    HumanityRules, By being in a positive phase as a posed to negative La Nina phase. NOAA has some good info on the El Nino Southern Oscillation. There are some suggestions that El Nino will get stronger as the oceans warm and La Nina will potentially get weaker. Currently however, there is very little evidence to back this theory up especially since ENSO (La Nina) is in it's strongest negative phase for a long time. ENSO has a huge impact on annual temperature and it is the reason why the this year will no longer be the warmest on record.
  38. An Even Cloudier Outlook for Low Climate Sensitivity
    HumanityRules at 23:11 PM on 12 December, 2010 Try Trenberth 2002, it is approachable and even the abstract explains a lot. http://www.agu.org/pubs/crossref/2002/2000JD000298.shtml
    Moderator Response: [Daniel Bailey] A free copy can be found here.
  39. An Even Cloudier Outlook for Low Climate Sensitivity
    Re: Argus (5)
    "- And are there no "major flaws" in the criticism? How come the 'good guys' are always right on this web site, and 'the bad guys' are always wrong? It looks suspicious... "
     Please refrain from characterizing things in terms of good vs bad. In peer-reviewed science there is always going to be discussion, with an eventual coalescing of opinion into a right, wrong and shades of both regarding consensus of opinion on studies. Those papers receiving such close inspection as Mann 1998 or Lindzen and Choi 2009 either end up being robustly defended because evidence supported their premise (Mann 1998) or abandoned (Lindzen and Choi 2009). Papers eventually falling by the wayside still serve a useful purpose in that a greater and deeper understanding of the science remaining is developed. But that does not make authors of failed peer-reviewed papers bad. Or those of confirmed papers good. The Yooper
  40. CO2 only causes 35% of global warming
    Continued from comments on the 'human fingerprint in the seasons' thread. #166: "Attributing these observation to a primary cause, which seems to be the intention here, seems problematic." I agree that is a very valid and significant question. In the seasonal fingerprint thread, John cited Braganza et al 2004. They looked at 5 indices pulled from sea surface and air surface temperature data, concluding Over the last 50 years, observed linear trends in the global-mean temperature (GM), the land-ocean temperature contrast (LO), the magnitude of the annual cycle in temperature over land (AC) and the Northern Hemisphere meridional temperature gradient (MTG) are found to be significantly larger than changes expected due to internal variability and changes in solar and volcanic aerosol forcing. ... Consistency between the observed and GS [greenhouse gas plus sulfate aerosol] trends in four different indices suggests that anthropogenic forcing has had a large influence on observed changes during the later part of the twentieth century. Their models include water vapor; however, your question still persists: How much GHG warming is due to water vapor and how much is CO2 and the other nasty gases? For this, look at Schmidt et al 2010. First they make this utterly critical point: The system which is relevant for our discussion of climate sensitivity consists of the atmosphere (winds, temperature, humidity, clouds, etc.) coupled to a simplified upper ocean component that allows SST to vary [Charney, 1979]. In this system, CO2, other trace GHGs, solar variations etc. are forcings, while the changes to internal prognostic variables corresponding to clouds and water vapor (that occur as a function of other changes in climate, which then go on to change the radiative transfer in the climate themselves) will be feedbacks. Among their conclusions: ... given the uncertainties, that water vapor is responsible for just over half, clouds around a quarter and CO2 about a fifth of the present‐day total greenhouse effect. Given that the attribution is closer to 20% than 2%, it might make more intuitive sense that changes in CO2 could be important for climate change. No doubt you're thinking 'Bazinga! He just said CO2 is only 20%!'. However, look next at Lacis et al 2010: This allows an empirical determination of the climate feedback factor as the ratio of the total global flux change to the flux change that is attributable to the radiative forcing due to the noncondensing GHGs. This empirical determination leads then to a climate feedback factor of 4, based on the noncondensing GHG forcing accounting for 25% of the outgoing flux reduction at the TOA for the full-constituent atmosphere. This implies that Earth’s climate system operates with strong positive feedback that arises from the forcing-induced changes in the condensable species. A direct consequence of this combination of feedback by the condensable and forcing by the noncondensable constituents of the atmospheric greenhouse is that the terrestrial greenhouse effect would collapse were it not for the presence of these noncondensing GHGs. It appears that CO2 (and the other noncondensing gases) is the driver of this car; there are four passengers, all urging the driver to go faster. The very excitable Water Vapor is riding shotgun, the back seat is full of Clouds. If the driver jumps out, the car stops because Water Vapor and Clouds don't drive. If the passengers quit yelling 'faster', the car keeps going, just at a more reasonable speed. To take this metaphor one step further, by increasing atmospheric CO2 concentration, we turned what was a very responsible adult driver into a wild and crazy teenager.
  41. DMI and GISS Arctic Temperatures: Hide the Increase?
    My thanks to Klaus for further statistical analysis and valuable input, and also to Pavel for pointing out (elsewhere) that the former USSR "NP" Arctic data was of course from drifting manned stations rather than buoys! I have now corrected this mistake (which appeared in the original advanced version).
  42. The human fingerprint in the seasons
    #166: "any primary source of warming (Human CO2, solar whatever) will always contain a GHG component because of the condensable GHG in the system." We must agree that both the condensable and the non-condensable GHGs are involved or else there's little to discuss. "Why us "if' when we all know GHGs are always playing a role?" Because 'us' is currently ~30 Gtons of CO2 each year. "All I see is that we can say we live in a warming world" Thank you! "Attributing these observation to a primary cause, which seems to be the intention here, seems problematic." I agree that is a very valid and significant question. Dana did a nice piece on this, which has yet to get any comments. As this is no longer a 'seasonal fingerprint' question, I'll put the rest of this long-winded reply there (hopefully making Dana feel better). As to your #167: 'what about clouds?', I'm going to leave that alone for now. There are some other active threads on the cloud question.
  43. The 2nd law of thermodynamics and the greenhouse effect
    Re #153 Philippe Chantreau you wrote:- " How does Claes Johnson theory fare? The way I see it, according to his theory, a multiple mirrors type concentrating solar plant can not work." I have read Claes Johnson's paper and, although he has a differnt approach - more to do with him not being a native English speaker - I don't see how you can say a solar concenterator can't work. Solar concentrators work becaust the photons arriving at the Earth, although reduced in number by the inverse square law, still have the energy of the 5780K Sun; so if you use a mirror (or a lens) to concentrate sunlight you can, if there are no other losses(!) achieve an image of the Sun not just with its original brightness but with the original temperature (Don't, for goodness sake, look at such an image.)
  44. The 2nd law of thermodynamics and the greenhouse effect
    Phillipe Chantreau @153 Perhaps you misread that which I wrote? Which was " so low that it cannot be measured." (my reply to statement D) The "it" referred to a theoretical change in temperature of the planet and not to the quantity or nature of the radiation involved. The downward radiation can be measured but my understanding, at present, is that has no effect, as its frequency is too low to raise the temperature of matter at a warmer temperature.....2nd Law of Thermodynamics...true or false?
  45. The 2nd law of thermodynamics and the greenhouse effect
    Re #159 AWoL you wrote:- "Is an understanding of quantum physics and relativity necessary for understanding of climate models?" Indeed it is. Quantum physics arose because there was no satifactory explanation for radiative transfer of energy that could be derived from classical mechanics. Classical mechanics (kinetic theory) was OK for heat in atoms and molecules but it simply didn't work for radiation, even with Maxwell's electromagnetic equations. It was Max Planck (On the Law of Distribution of Energy in the Normal Spectrum - 1901) who, basing his work on Gustav Kirchhoff's 'black body' paper (On the Relation Between the Emissive and Absorptive Power of Bodies for Heat and Light - 1862) who opened the door to understanding of the quantum aspects of radiation and matter. In turn Einstein (1905, 1909 and 1917) picked up the torch and the rest, as they say, is history. As for recommending books, that is rather difficult. There are translations of the original works and it is highly advisable to read them because the subject, as it is taught today, is widely misunderstood, particularly Kirchhoff. The relatioship between the Earth and the Sun in terms of energy is very simple in some ways but when you read in all climatological explanations that the Earth 'emits in the infrared like a black body', and 'the Earth's temperature is dependent on its albedo', the you must realise that 'climatology' has fallen at the first fence and you are completely lost, the only thing to do is to turn round and go back to the beginning.
  46. An Even Cloudier Outlook for Low Climate Sensitivity
    I guess I should know this but how does El Nino cause global temperatures to increase? I'm finding it hard to get an answer from Google.
  47. An Even Cloudier Outlook for Low Climate Sensitivity
    Argus@5: Lindzen and Choi are welcome to point out the "major flaws" in the criticisms. The fact that they have chosen to not defend their position in the face of criticism suggests that they feel the criticism is correct. Science is a dog fight. People get criticized all the time. If you think you are right you defend yourself. If you chose not to defend your position the science moves on. Look at the criticism of the hockey stick: Skeptics criticized the result and Mann has responded with more data to support his position.
  48. Berényi Péter at 23:06 PM on 12 December 2010
    Ice age predicted in the 70s
    Did scientists predict an impending ice age in the 1970s? It was most certainly communicated they did.
  49. An Even Cloudier Outlook for Low Climate Sensitivity
    This post does brush on an important point that isn't properly clarified: the short term changes caused by ENSO might lead to a different cloudiness pattern than you get with a global warming (because ENSO's pattern of warming is different to what you expect from global warming and cloud feedback is not linear in temperature, not to mention changes in circulation etc). However, models account for this, so it's a good paper that sidesteps Spencer's cause/effect so it can be used to test models: and the data from the past 10 years don't contradict the model calculations. So we can be a bit more confident in them. Which is a much more complicated 'point' than just reading the abstract suggests...
  50. An Even Cloudier Outlook for Low Climate Sensitivity
    Argus, I definitely recommend reading the criticism of Lindzen & Choi. You can't be sure their results are global anyway, and the ability to change their result by several-fold just by changing the selected periods by a few months means their approach looks seriously, seriously flawed. Unless they have a very strong justification for their time period choices, which they haven't presented.

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