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Comments 109451 to 109500:

  1. A detailed look at Hansen's 1988 projections
    Ricardo, you are mostly right but not completely. (Unless I missed something more, which is of course now a non-negligible option.) Shouldn't Table 1 give the realised Greenhouse Gas (GHG) Concentration in 1984 and 2010, rather than the one from Scenario B? The calculations seem to be based on scenario B, not the realised emissions. The real ones may be most like scenario B compared to A or C, but are unlikely to be identical. If you only want to test the model, you need to use the observed emissions as input.
  2. A detailed look at Hansen's 1988 projections
    Sense Seeker, you missed something. Two quotes from the post: "Scenario A assumed continued exponential greenhouse gas growth, which did not occur." "Hansen's Scenario B has been the closest to the actual greenhouse gas emissions changes."
  3. A detailed look at Hansen's 1988 projections
    Something here does not make sense. Nowhere do you mention what the actual emissions WERE over the intervening period. You cannot simply compare one of Hansen's scenarios with what actually happened in terms of outcomes, if you do not take into account the inputs. If the temperature curve nicely follows Hansen's scenario B, but the emissions increased exponentially (i.e., according to scenario A), Hansen's model was overestimating by a much larger margin.
  4. How we know the sun isn't causing global warming
    Dana1981, I still don't think your section on the D-O events is particularly convincing, especially with regards to the so called "timing flaw" you mention. For the sake of argument, if the LIA was the last cold phase of the D-O cycles, we could place the MWP as the peak of the last warm-phase, and subsequently the Earth should be warming now. Remember, the 1470 figure is the periodicity -- the time interval between peaks (or troughs). The Earth was in a trough several hundred years ago, and it should now be heading towards a peak (i.e. warming). So the fact that the LIA may have been the most recent cold phase of the D-O cycles does not preclude them from adding to the recent warming; quite the opposite. Please see my previous post on this thread for my reasoning on why D-O events cannot have had anything more than a negligible affect on global temps over the past few centuries.
  5. Philippe Chantreau at 18:05 PM on 20 September 2010
    Jupiter is warming
    And Bob, let's not forget that Venus is warmer than Mercury, which is closer to the Sun...
  6. Philippe Chantreau at 17:58 PM on 20 September 2010
    It's cosmic rays
    Continued from the thread mentioned above: HR, the word would be laughable but, really, what is there to hang on in the Duplissy paper itself? What paper since Duplissy has been published using CLOUD data? References? Anything yielding more conclusive results? The point was not to reveal problems in the experimental design, but the problems were uncovered nevertheless. If those ultra clean walls can release vapors susceptible of corrupting the results, I don't even want to begin imagine what happens in the real atmosphere, where CCN are already present by the hundreds per cubic cm.
  7. Philippe Chantreau at 17:41 PM on 20 September 2010
    A South American hockey stick
    HR, the word would be laughable but, really, what is there to hang on? What paper since Duplissy has been published using CLOUD data? Do you have something of any substance? The point was not to reveal problems in the epxerimental design, but the problems were uncovered nevertheless.
  8. 2nd law of thermodynamics contradicts greenhouse theory
    KnuckleDragger, to explicitly address your first question on absorption/reflection, thinking in this terms could be confusing. In everyday life we call reflection the "bouncing back" of light from a solid or liquid surface. In a gas there's no surface and it could be hard to understand how "reflection" may occur. I think it's easier to think in terms radiation absorption/emission. Quoting from the post: "Any substance that absorbs thermal radiation will also emit thermal radiation; [...]. The atmosphere absorbs thermal radiation because of the trace greenhouse gases, and also emits thermal radiation, in all directions." The backward emitted radiation is what you (and others) call reflection. So, the answer to your question is that CO2 at high concentration is a good absorber and reflector.
  9. Global warming and the unstoppable 1500 year cycle
    Here is a question to the skeptics: why don’t you provide a classification of the different climate theories held by climate skeptics ? People who don’t believe in global warming have entirely different convictions from those who do believe the earth is warming due to natural causes. In fact, these 2 points of view are as different as any skeptic theory is from the AGW theory. In order to advance the discussion, the classification “climate skeptic” is just not enough. F.i. the alternative theories could be named: NoGW, NatGW (with subclassifications: NatGW_solar, NatGW_ocean_currents, …), NonCatAGW (non-catastrophical AGW), etc. AGW is just one of the many possible climate theories – with an overwhelming amount of evidence on its side …
  10. A detailed look at Hansen's 1988 projections
    One thing that folks should keep in mind is that your typical el-cheapo Best-Buy/Walmart/whatever laptop has more computing horsepower than what Hansen had available to him to conduct his climate-modeling simulations back in 1988. This should put things in perspective here, and also give folks a fuller appreciation of Hansen's genius.
  11. Global warming and the unstoppable 1500 year cycle
    (#12)My impression actually is that most skeptics claim we are cooling, and have just entered a cooling phase that will go on for decades. Skeptics not only believe that the Earth is cooling; they also believe that the Earth is warming. They believe that the warming can be attributed to natural causes, and they believe that the warming is due to the urban heat-island effect. In addition, they believe that it's impossible to tell whether the Earth is warming or cooling because so many temperature stations are set up next to air-conditioners and bbq grills. They believe all of these things; that's how they make sure that they have all of their bases covered.
  12. A detailed look at Hansen's 1988 projections
    @paulm: That website proves nothing. Radiative forcing F is a multivariate nonlinear function. But for small variations, we can Taylor-expand and to first order it is the sum of the first derivatives. The particular objection raised is that for example d^2F/d(CO2)/d(N2O) is not zero. I agree it's not. But its contribution to dF is much smaller than the linear part. As it's unknown, it contributes to the uncertainty (error-bar) in the calculation.
  13. A detailed look at Hansen's 1988 projections
    The other thing that I think should be pointed out is that Hansen scenario B was also taking into consideration a large volcanic eruption in 1995 while Pinatubo - which can be clearly seen in the actual data - was in 1991 - once you also correct for that the scenario B already looks identical to real measured values!
  14. Why positive feedback doesn't necessarily lead to runaway warming
    Further search of previous research of the temperature limiting factors of biosphere... From http://www.dbio.uevora.pt/Micro/Brock.pdf ("Life at high temperatures", review on prior research, unfortunately it doesn't include much on terrestrial vascular plants.) "We found visible algal growth (of the unicellular blue-green Synechococcuts) at temperatures up to 73° to 75°C, but not at higher temperatures (24)" and "Quantitative studies of the algal mats along thermal gradients in hot springs have shown a definite correlation between the temperature and the algal biomass (33). In the Yellowstone hot springs, maximum algal biomass was found at albout 55°C, and it falls off sharply as the temperature increases above 55°C (34)." So one limit of inhibition for high (too hot for humans) temperatures is 55°C and photosynthesis ends at 75°C. Above this temperature all photosynthecic life will decompose and photosynthesis needs to be born or moved to the area again. Geological processes will eventually bury the decomposed carbon. further: "Thus, it is surprising that eucaryotic algae are not common at temperatures above 40°C, whereas eucaryotic fungi are found up to 60°C (14)." So 40°C is about the maximum limit when oceans will turn into carbon emitters. lastly: a point on scientific inertia... "Most of the surface of the earth has a moderate temperature, with an average of 12°C (15)." checking this up, it turns out this was an approved value in 1955: "15. H. F. Blum, Time's Arrow and Evolution (Princeton Univ. Press, Princeton, N.J., 1955)."
  15. A detailed look at Hansen's 1988 projections
    I wonder if you would consider typesetting the math with LaTeX? Would make it lots more readable. You could e.g. use http://www.codecogs.com/latex/eqneditor.php. Or if you already know LaTeX, just use TTH: http://hutchinson.belmont.ma.us/tth/
  16. A detailed look at Hansen's 1988 projections
    Heres some interesting analysis... http://residualanalysis.blogspot.com/2010/02/twin-ghgs-paradox.html The Twin GHGs Paradox The means by which a greenhouse gas (GHG) forces climate change is sometimes called radiative forcing.
    Moderator Response: Please provide more context when you post a link.
  17. actually thoughtful at 14:30 PM on 20 September 2010
    A detailed look at Hansen's 1988 projections
    It is hard to look at Hansen's 1988 work without seeing he got it right! A few quibbles, but the major mechanisms are all included, and he is off by a few tenths of a degree over 22 years! And the fix is very clear - he used 4.2 instead of 3 or 3.4 for climate sensitivity. The takehome message is climate scientists have this dialed in. With 22 years more research, current models are that much better. "Hansen got it wrong" is a lie - pure and simple.
  18. A detailed look at Hansen's 1988 projections
    Misprint on the first line. Says 1998; should be 1988.
    Response: Fixed, thanks
  19. Climate sensitivity is low
    Re: Timothy Chase (51) Thanks for taking the time to put together such a thorough comment. It's appreciated. The Yooper
  20. A South American hockey stick
    @HR: quoting Judith Curry doesn't automatically equate providing scientific evidence that supports your arbitrary claims. I'm still waiting to have some valid sources cited to support your claim that 1/3 to half the warming is anthropogenic. Otherwise, we'll have to assume you pulled these figures out of the place where TSI is nil.
  21. A South American hockey stick
    Re: HumanityRules (47) You should have a read of this. And ponder on it. The Yooper
  22. 2nd law of thermodynamics contradicts greenhouse theory
    Re: KnuckleDragger (11) I'm glad you're inquisitive and I'm glad you're here.
    "It seemed to me, that the 2nd law put the final nail in the coffin of this (CO2) debate. Yet, it's still alive. How is it possible ?"
     This is a common objection from people who do not understand the greenhouse effect (or the 2nd law of thermodynamics, for that matter). A simple understanding of the greenhouse effect:
    Longwave radiation from the earth’s surface is absorbed by many trace gases, including water vapor and CO2. The absorption causes these gases to heat up and energy is radiated back out – both up and down. The upward radiation is effectively “no change”. The downward radiation adds to the energy received from the sun and heats up the surface of the earth more than if this downward radiation did not occur.
    The 2nd "law", simply put:
    "Heat generally cannot flow spontaneously from a material at lower temperature to a material at higher temperature"
    What this means is this:
    No net energy can flow from a cold body to a hot body. In the case of the real “greenhouse” effect and the real 2nd law of thermodynamics, net energy is flowing from the earth to the atmosphere. But this doesn’t mean no energy can flow from the colder atmosphere to the warmer ground."
    It simply means more energy flows from the warmer surface to the colder atmosphere than in the reverse direction. Sources: Here and here.
    "The theory that man made CO2 is the cause of Global Warming has had so meny holes punched through it - I don't understand how it's survived this long...What is it that I'am not understanding?"
    The first part of your statement is wrong on every level, but I can understand the confusion you must feel. If it's so wrong, why does every scientific body in the world support it? Why does Shell Oil, of all things, support it? KnuckleDragger, I'm a simple man too. If someone is telling you that CO2 doesn't warm the Earth or that it's the sun or that it's cooling, or it's a natural cycle, then you have 2 possible answers:
    1. They don't understand quite a bit about science, physics, the greenhouse effect or pay attention to developments in the natural world... OR... 2. They're lying to you...
    The greenhouse effect is quite well understood. Here's a quick backgrounder on the GHE, CO2 and AGW (the important bit is the response to Question 1 & the 8 steps outlined). Basically, it come down to this: No-one has been able to come up with a physics-based alternative to the observed & predicted effects of CO2 and GHG's that explains what we can see and measure that ALSO explains why CO2 derived from fossil fuels DOESN'T act as a GHG. At this point, being an inquisitive man, you probably will have more questions. Feel free to ask; the kind people here will be glad to help you gain an objective understanding. The Yooper
  23. A South American hockey stick
    HR, Unfortunately, Judith Curry cites no sources for her probability "weighting". She does, however, assert that the colors of the Italian flag can help us figure it all out.
  24. A South American hockey stick
    43.Philippe Chantreau I actually linked to the video because he spends most of the time presenting data (including paleo) suggesting there is a fair degree of natural variability in the pre-industrial record. As he says he's not presenting answers just raising questions. The intent was to use it to highlight the wider discussion around natural variability not specifically GCR's Maybe you know that Duplissy et al (2010) was the 2009 data from a pilot run. The whole point was to bring to light errors in experimental design. I have no sense of the difficulty involved in these highly complicated physics experiments but I expect its high. Nobody really holds any value to this data, it's more like an update on how this multi-million dollar project is going. As well as Svenmark there are a total of 19 collarborating groups, from 19 separate institutes working on this project. It's laudable that you should suggest that this work is being subverted by deniers. 42.RickG Judith Curry suggests the IPCC has a very low estimate of uncertainty which leads them to the conclusion that late 20th C warming is 5% assigned to uncommitted belief, 67% assigned to anthropogenic forcing, 28% assigned to natural variability. Her own assessment of uncertainty leads her to believe 40% assigned to uncommitted belief, 30% assigned to anthropogenic forcing, 30% assigned to natural variability. This means anthro could be anywhere between 30-70%, but natural could also be 30-70%. I based my own opinion on papers looking at regional natural variability and email exchanges with their authors. But I also hold the opinion that the IPCCs drive to reduce uncertainty is not based on science but on political necessity.
  25. 2nd law of thermodynamics contradicts greenhouse theory
    So is CO2 a good reflector while a poor absorber or is it a good absorber but a poor reflector ? It seemed to me, that the 2nd law put the final nail in the coffin of this (CO2) debate. Yet, it's still alive. How is it possible ? The theory that man made CO2 is the cause of Global Warming has had so meny holes punched through it - I don't understand how it's survived this long. It's been de-bunked by simple sciance on so meny levels, it should have been dead long ago. All the while, people far smarter than myself keep pushing it along. What is it that I'am not understanding? I'm a simple man, thats probably a bit more inquisitive than most, looking for answers. Which is what lead me here.
    Moderator Response: Please don't post the same comment repeatedly. I deleted your second one.
  26. Global warming and the unstoppable 1500 year cycle
    The problem for Thingadonta’s arguments is that global warming is occurring as evidenced by its effects in both the Arctic and Antarctic. In the north there is empirical evidence of depletion of sea ice and melting of the Greenland ice cap. In the south there is melting of the West Antarctic ice sheet and retreat of glaciers, while in East Antarctica there is evidence of increasing ice loss at the fringes of the ice cap. Grace satellite measurements confirm that these changes are occurring and doing so at an increasing rate. Thingadonta seems to assert that since ice ages are a global phenomena, this disproves that CO2 induced global warming is now occurring. Frankly, I don’t understand that argument. The present problem with CO2 is that human activity is responsible for it increasing at rates vastly in excess of that which would otherwise occur. In decades we release into the atmosphere what would otherwise take hundreds of millennia to accumulate. Can that occur without causing the global warming which is now so clearly evident?
  27. Global warming and the unstoppable 1500 year cycle
    "Although there are a lot of people who deny the warming, my understanding is that most skeptics believe there is a natural warming." My impression actually is that most skeptics claim we are cooling, and have just entered a cooling phase that will go on for decades. "It's cooling" is #4 on the skepticalscience most used skeptic arguments and I think that's probably about right. What I see when I trawl google news for comments sections of climate related news articles is a lot of people throwing out the claim that the Earth has stopped warming and is now cooling. They cite Phil Jone's statement about 1995-, they cite a recent switch into a negative PDO. They cite certain russian scientists who predict the maunder minimum stuff.
  28. Global warming and the unstoppable 1500 year cycle
    Answering #4, Daved Green- The problem here is not so much that being basic, it lacks detail, but rather, that the logical flow of the article is jerky and scattered, and the wording fatally imprecise. Under such circumstances, since, as #3 points out, "'Skeptics' use bits of science like flack to deflect focus from their core arguments", they latch on to each one of these shortcomings and do exactly that -- with gusto and great effect. As an example of the jerky flow, consider even the very first sentence. It announces that there are two things 'interesting'. Then it immediately lists them. But frankly, from that list, neither one sounds 'interesting'. So already the logical flow most plausibly promised by the opening sentence has been lost. But then the article switches to the 1500 year cycle itself. This switch is quite abrupt, since we STILL haven't seen anything 'interesting' in the "two things interesting". But here too, we fail to keep the logical flow: for the unfortunate phrase "global temperature see-saw effect" spoils the whole paragraph. How so? Because the phrase "global temperature" would most logically mean a -single- temperature, which in turn would most likely be an -average- temperature. But the 'see-saw' described must be rising temperature in one hemisphere, while the temperature falls in the other (and vice versa). At best, this would be an example of the rhetorical effect known as 'paraproskokian', since the expected meaning of the word turns out not to be ther right one. But as Wikipedia points out, paraprosdokiam "is frequently used for humorous or dramatic effect, sometimes producing an anticlimax" -- none of which fits here. (See http://en.wikipedia.org/wiki/Paraprosdokian). Frankly, if I wasn't already convinced of the basic truth of the AGW hypothesis, this article would not have convinced me either. It would not even have convinced me to research it further -- especially since it contains no references for its highly contentious claims. BTW: that final contentious conclusion is another example of fatal imprecision in wording: what is being "recorded all around the world" is NOT "the current temperature increase caused by CO2". What is being recorded is merely "the current temperature increase". How much of it is caused by CO2 is exactly the bone of contention (assuming that no one still doubts the accuracy of the measurement -- although you know that because of 'Climategate' they do doubt it). You only give skeptics excuses for disbelief when you misstate it that badly. Unsupported statements of the central thesis (here that CO2-caused temperature rise is already being recorded) belong in the proem, the statement or perhaps on the conclusion, but ONLY when the support has been provided in (the body of) the argument. But where IS it? It just isn't there. Without it, you have no rebuttal at all.
  29. Climate sensitivity is low
    Dana, over at Climate Progress you wrote:
    I should mention, the 'Climate sensitivity' is not specific to CO2′ section isn't quite correct because different forcings have different efficacies. I updated the advanced version of this rebuttal to clarify this point. Here's the link if you want to do the same: http://www.skepticalscience.com/climate-sensitivity-advanced.htm
    I was trying to respond to that, but too many links has put my post in the could-be-spam queue, so I thought I might post this here as well in the hope that some might find it helpful. Definition of Radiative Forcing:
    The definition of RF from the TAR and earlier IPCC assessment reports is retained. Ramaswamy et al. (2001) define it as 'the change in net (down minus up) irradiance (solar plus longwave; in W m^–2) at the tropopause after allowing for stratospheric temperatures to readjust to radiative equilibrium, but with surface and tropospheric temperatures and state held fixed at the unperturbed values'. 2.2 Concept of Radiative Forcing http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-2.html
    The idea here is that increased solar radiance or increases in CO2 concentration affect the balance of radiation entering/leaving the climate system -- and will result in a response at the "top of the atmosphere" or - tos - which is typically taken to be at the tropopause which separates the troposphere and the stratosphere. Feedbacks are in response to this change. Definition of Climate Sensitivity:
    The long-term change in surface air temperature following a doubling of carbon dioxide (referred to as the climate sensitivity) is generally used as a benchmark to compare models. Climate Change 1992 The Supplementary Report to the IPCC Scientific Assessment, pg. 16 http://www.ipcc.ch/ipccreports/far/IPCC_Suppl_Report_1992_wg_I/ipcc_far_wg_I_suppl_material_full_report.pdf
    The above definition of climate sensitivity is however for the Charney Climate Sensitivity that takes into account the fast feedbacks, e.g., water vapor, clouds, sea ice, etc., but omits the slow feedbacks associated with changes in vegitation, feedbacks due to the carbon cycle and ice sheets -- the latter of which are land-based. Definition of Efficacy:
    Efficacy (E) is defined as the ratio of the climate sensitivity parameter for a given forcing agent (λi) to the climate sensitivity parameter for CO2 changes, that is, Ei = λi / λCO2 (Joshi et al., 2003; Hansen and Nazarenko, 2004). Efficacy can then be used to define an effective RF (= Ei RFi) (Joshi et al., 2003; Hansen et al., 2005). For the effective RF, the climate sensitivity parameter is independent of the mechanism, so comparing this forcing is equivalent to comparing the equilibrium global mean surface temperature change. 2.8.5 Efficacy and Effective Radiative Forcing http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-8-5.html
    Why Efficacies of Different Forcings are Different:
    The efficacy primarily depends on the spatial structure of the forcings and the way they project onto the various different feedback mechanisms (Boer and Yu, 2003b). Therefore, different patterns of RF and any nonlinearities in the forcing response relationship affects the efficacy (Boer and Yu, 2003b; Joshi et al., 2003; Hansen et al., 2005; Stuber et al., 2005; Sokolov, 2006). Many of the studies presented in Figure 2.19 find that both the geographical and vertical distribution of the forcing can have the most significant effect on efficacy (in particular see Boer and Yu, 2003b; Joshi et al., 2003; Stuber et al., 2005; Sokolov, 2006)... 2.8.5.1 Generic Understanding http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-8-5-1.html
    For more on radiative forcing and related concepts please see: Chapter 2: Changes in Atmospheric Constituents and in Radiative Forcing http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2.html Note: calculations performed by climate models do not involve the concepts of forcing, climate sensitivity or efficacy. The calculations of climate models are themselves based up the physics. Analysis in terms of forcings, climate sensitivity and efficacy only come afterward -- as a means of conceptualizing the results for the ease of our understanding.
  30. Should The Earth Be Cooling?
    No worry's Daniel-- I also make the same mistake from time-to-time. My comment/clarification was mostly directed at "skeptics".
  31. Should The Earth Be Cooling?
    Re: Albatross (60) Thanks for the reminder. :) I was a little fired up & used KL's quote back in the context he meant it (the non-science, or layman's everyday usage). I should probably have corrected that misunderstanding as well. But it's difficult to catch everything in a comment like that because of the sheer amount of misunderstandings going on. I will try to exercise more judiciousness in my words. BTW, the NAS definition you cite is very similar to the NAS statement in May on global warming:
    " A strong, credible body of scientific evidence shows that climate change is occurring, is caused largely by human activities, and poses significant risks for a broad range of human and natural systems…. Some scientific conclusions or theories have been so thoroughly examined and tested, and supported by so many independent observations and results, that their likelihood of subsequently being found to be wrong is vanishingly small. Such conclusions and theories are then regarded as settled facts. This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities."
     Source here. Thanks again, The Yooper
  32. Climate sensitivity is low
    From the main article:
    A 2008 study led by James Hansen found that climate sensitivity to "fast feedback processes" is 3°C, but when accounting for longer-term feedbacks (such as ice sheet disintegration, vegetation migration, and greenhouse gas release from soils, tundra or ocean), if atmospheric CO2 remains at the doubled level, the sensitivity increases to 6°C based on paleoclimatic (historical climate) data.
    Hansen et al estimate Earth System Sensitivity (ESS - that includes slow feedbacks) over Charney Sensitivity (CS - that only includes fast feedbacks) - or ESS/CS - at 2:
    Paleoclimate data permit evaluation of long-term sensitivity to specified GHG change. We assume only that, to first order, the area of ice is a function of global temperature. Plotting GHG forcing [7] from ice core data [18] against temperature shows that global climate sensitivity including the slow surface albedo feedback is 1.5°C per W/m 2 or 6°C for doubled CO2 (Fig. 2), twice as large as the Charney fastfeedback sensitivity. Note that we assume the area of ice and snow on the planet to be predominately dependent on global temperature, but some changes of regional ice sheet properties occur as part of the Earth orbital climate forcing (see Supplementary Material). pg. 220, James Hansen et al.(2008) Target Atmospheric CO2: Where Should Humanity Aim?,The Open Atmospheric Science Journal, 2, pp. 217-31 http://pubs.giss.nasa.gov/docs/2008/2008_Hansen_etal.pdf
    A more recent estimate puts ESS/CS at about 1.4:
    As shown in Table 1, none of these assumptions greatly changes our estimate of ESS/CSacross all of the analyses presented in this article, the smallest value of ESS/CS we obtain is 1.3, and the largest is 1.5. Our combined modelling and data approach results in a smaller response (ESS/CS~ 1.4) than has recently been estimated using palaeo data from the Last Glacial Maximum, 21,000 years ago (ESS/CS ~ 2). This is probably due to the fact that transitions from glacial to interglacial conditions in the Quaternary involve large changes in the Laurentide and Eurasian ice sheets (see, for example, ref. 36), which result in a significant large-scale albedo feedback in these regions that is irrelevant for climates warmer that present. pg. 63, Daniel J. Lunt et al. (January 2010) Earth system sensitivity inferred from Pliocene modelling and data, Nature Geoscience, Vol. 3
    Either way the climate sensitivity that people have been talking about underestimates the warming that we can expect because by definition it omits the slow feedbacks -- which aren't necessarily that slow (e.g., the reduction in plant efficiency over the past decade, the saturation of some ocean CO2 sinks, Boreal forests in Canada, rising levels of methane emissions due to permafrost melt in Arctic tundra and Arctic shallow water continental shelves, e.g., near the coastline of Siberia.
  33. Climate change: Water vapor makes for a wet argument
    johnd #138: "Is it absolutely certain that natural CO2 emissions are not rising faster than offsetting natural sinks in response to increased temperature?" Yes. Yes it is. We know that the steady increase of atmospheric CO2 (and ocean carbonic acid) over the past century has been due to human emissions. See 'empirical evidence that humans are causing Global warming'. Besides, how can you really think that warming is causing the CO2 rise when the CO2 has been increasing steadily while warming has undergone numerous significant fluctuations... no correlation.
  34. Should The Earth Be Cooling?
    Daniel @58. Thanks for calling Ken on his misinformation @56. Just one nit pick, one has to be careful about distinguishing between a "hypothesis" and a "theory". Many people, it seems, try to discredit or belittle the physics behind AGW by referring to it as a "only a theory", when, if that is their intent, they should be referring to the "hypothesis of AGW". The increased radiative forcing from elevated GHGs is a well established and tested theory. In the science world, a "theory" carries a lot more weight than a "hypothesis". "According to the United States National Academy of Sciences, Some scientific explanations are so well established that no new evidence is likely to alter them. The explanation becomes a scientific theory. In everyday language a theory means a hunch or speculation. Not so in science. In science, the word theory refers to a comprehensive explanation of an important feature of nature supported by facts gathered over time." [source, Wikipedia]
  35. What were climate scientists predicting in the 1970s?
    Another oldie, but a goodie: Bolin and Bischof, 1970 Variations of the carbon dioxide content of the atmosphere in the northern hemisphere Six years of measurements (1963-1968) of carbon dioxide in the troposphere and the lower stratosphere are presented. The data reveal an average annual increase of the CO2 content of 0.7 +/- 0.l ppm/year, while during this time the annual industrial output has increased from about 1.9 ppm to 2.3 ppm/year. ... Accepting 35% as being the most likely net increase in the atmosphere as compared with the total output yields 332 ppm for 1980 and 371-378 ppm for year 2000 if using the values for CO, output based on the OECD estimates. And the 2000 annual CO2 average was: 369.4ppm
  36. Should The Earth Be Cooling?
    KL #56 "Some facts please kdkd" Facts: If I (or any other capable person) were to do the statistics examining the linear trends, the cherry picking you've done by eyeball would be a trend that I'm 99.99% sure would be shown to be statistically indistinguishable from zero. Which in turn doesn't mean no warming or cooling, it means that there's insufficient data to determine the trend on that time scale. I stand by my previous comment that your position is illogical, incorrect, and theoretically unsupportable repetitious rubbish. Is that a sufficiently factual for you?
  37. Climate change: Water vapor makes for a wet argument
    Also, the "dismissing" of BOM data because was because it measured what was important to agriculture, every seen it is perfectly well understood and explicable from known physics but it did not measure the variables necessary for investigating water vapour/radiation relationships. Also your continuing insistence on understanding carbon cycle is interesting. AR4 models do not on the whole include carbon cycle at all - because it assumed to be a slow feedback. The understanding of what part of our emissions remains in atmosphere is from measurement again. This is looking for excuses not looking for truth.
  38. Climate change: Water vapor makes for a wet argument
    Johnd - "not understood" - simply not true. We MEASURE all this stuff. You are looking for microscopic local changes and inferring this can drive large scale global trends while at the same time arguing that the MEASURED increase in backradiation from greenhouse gas - a much larger forcing - is insignificant. I am sorry but you seem to engaged in wishful thinking only. I have wasted enough time trying to explain. I'm out of here.
  39. Climate change: Water vapor makes for a wet argument
    johnd at 06:37 AM, correction, that should read "If that is the case what are the limits that any imbalance reaches either side of balanced before the natural PROCESSES adjust to overcome imbalances over or under?"
  40. Climate change: Water vapor makes for a wet argument
    Bibliovermis at 06:10 AM, the point being made is that until complete understanding is reached about what drives the natural sources, and sinks that are able to accommodate seasonal variations many times the total amount of human emissions, then there are many assumptions having to be made. One could be that the natural cycles adjusts to seek a balance. If that is the case what are the limits that any imbalance reaches either side of balanced before the natural balances adjust to overcome imbalances over or under? Are the responses linear or do they progressively ramp up, or down responding to the degree of imbalance? Is it absolutely certain that natural CO2 emissions are not rising faster than offsetting natural sinks in response to increased temperature?
  41. Climate change: Water vapor makes for a wet argument
    human [CO2] emissions are tiny by comparison, 1/30th
    Johnd, that is a sophistic partial truth which is arrived at by focusing on one side of a natural cycle rather than considering the net amount. It has already been addressed on this site. How do human CO2 emissions compare to natural CO2 emissions? (argument #28)
    The natural cycle adds and removes CO2 to keep a balance; humans add extra CO2 without removing any.
  42. Climate change: Water vapor makes for a wet argument
    KR at 02:47 AM, you wrote "the fact that the primary IR emissions to space from water vapor come from above the cloud layers" Can you clarify that as I'm not sure what you mean, given that as water vapour rises it progressively gives up it's heat, condensing into clouds, the last of the heat being given up by whatever is remaining of the water vapour, obviously, at the level of which the highest clouds form.
  43. Climate change: Water vapor makes for a wet argument
    I think the point being missed with regards to both water vapour, the subject of this thread, and CO2 is whilst the effects may be felt in the upper atmosphere, the causes of water vapour, evaporation, and of the natural releases of CO2, human emissions are tiny by comparison, 1/30th, all are due to conditions that prevail in the micro-climate that exists at the earths very surface, both over land and the oceans. As I pointed out earlier, those whose interest lies in what happens within that micro-climate find conditions somewhat different to those whose interest begins with data collected 1.2m above ground level, and it will be such that as understanding of the processes that occur within that micro-climate improve, the causes, that will feed into providing greater understanding of the macro-climate, and the effects. I think the way in which the BOM data I referred to was generally dismissed because it was deemed to be for agricultural purposes is indicative of the lack of appreciation of just how important understanding the processes of the micro-climate is to the overall understanding of the climate generally, and the weather systems which ultimately define what the climate is at any given point of time.
  44. Climate change: Water vapor makes for a wet argument
    Re: KR (132) I was a little lazy in my previous linked graphic (it was a little dated, being from 2003). The AIRS site has more up-to-date graphics, like this one from 2009: I note in passing that Bermuda is still a world-leader in emissions. :) The Yooper
  45. The contradictory nature of global warming skepticism
    @Baz: "Where’s the heat, CBD, where’s the heat?" It's here, Baz, it's here!
  46. The contradictory nature of global warming skepticism
    @Baz: "because I've witnessed 10 years of flat HadCRUt data" The HadCRUt data isn't flat, no matter how much you claim it is. Stop repeating this false statement, or we won't have any other choice but to consider you a liar. "You may well point to other metrics as evidence, and that may be valid, but after all is said and done, I am sceptical that the future will be warm - based on those 10 years and the fact that we know so little about climate science." We know enough to say that the last 10 years aren't statistically significant. "Now that may well be illogical to you, even irrational. That's fine, I can live with that," So, you admit you're wrong, but you'd rather be wrong that accept the science? What are you doing on this web site, then? "but you have to understand that people like me, who hover on the fence, and who will be swayed by a few year's worth of data, are the norm, the mainstream." You're not, actually. Most people worldwide believe the warming is real, and that humans are responsible. Even if you were right (which you aren't), the argument still wouldn't make sense. It's like saying "most people believe the Earth is flat, so it's okay if I believe this as well, even though I've been presented with evidence to the contrary." "You're not going to change our view by pointing us to climate metrics that are still disputed by very eminent people." Which climate metrics are disputed by which very eminent people? Asking for a twenty year (or even 15) years period for statistical significance isn't controversial. "Let's be honest with each other, if ALL the scientists were on one side then to believe the opposite would be pretty obtuse." 97% isn't enough for you? Let's be honest with each other (and I don't care what you think, since you'll no longer respond to me): you have admitted yourself to not being rational, i.e. you will not accept any rational argument that goes against your unscientific opinion. No wonder you trust contrarians like Spencer and the Pielkes - they reinforce your belief, so you accept what they say wihout question. You've made it clear you have no credibility on this matter, and that you're only interested in spreading FUD. Please stop wasting our time.
  47. It's cosmic rays
    Regarding Duplissy et al. 2010 Results from the CERN pilot CLOUD experiment on their preliminary results, please see this comment on a different thread and make any subsequent comments here.
    Moderator Response: Thanks for helping keep the threads organized!
  48. The contradictory nature of global warming skepticism
    Baz... How can you state in one moment that 1995-2009 is 0.12C/decade but is "not statistically significant" while at the same time telling us that flatting temps from 2002 to 2010 is somehow this problem for global warming?
  49. Climate change: Water vapor makes for a wet argument
    johnd - CBDunkerson is quite right; small variations at ground level (to the extent there are any) will have insignificant effects on global warming. AGW is driven by radiative imbalances, which occur in the upper troposphere - the more GHG's present, the higher the emission mean for IR in the atmosphere, and the warmer the planet has to be to reach radiative balance. The cooling air at ground level is part and parcel of the "radiation fog" effect - a completely understood phenomena. That's a red herring in regards to climate change, quite frankly, and is no longer worth discussing. Water vapor has its primary effect in the upper troposphere as well - I can't find the link right now, but the fact that the primary IR emissions to space from water vapor come from above the cloud layers is why fairly simple average values are of use in global climate models. Clouds (lower in the atmosphere) do have an effect, but at a level where the consensus isn't certain whether it's net positive or net negative feedback - that's where most of the +/-1.5C in feedback for CO2 doubling comes from.
  50. Climate change: Water vapor makes for a wet argument
    My apologies - the map I posted here is indeed an emissions map (as johnd pointed out), not a concentration map. The appropriate map is the one Danial Bailey posted here. This also more clearly demonstrates the point I was trying (rather badly) to make: that when johnd thought that CO2 concentrations varied significantly with a range of a few meters, he was quite wrong. My apologies if my original post was misleading/incorrect.

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