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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 109201 to 109250:

  1. Climate Change: The 40 Year Delay Between Cause and Effect
    Also, yes, the atmosphere emits radiation in approximately the spectrum of the Planck's Law for a blackbody radiator (modified by the gas absorption bands).
  2. Climate Change: The 40 Year Delay Between Cause and Effect
    John - massive confusion here. IR is not heat for starters. Heat is energy being transferred by conduction between bodies at different temperatures. IR is energy as electromagnetic radiation. A CO2 molecule DOES absorbs radiation only in certain frequencies. It is anything but "clear" that it does otherwise. However, the atmosphere is also warmed by conduction. A molecule excited by absorption "heats" other molecules by collision. The CO2 molecule will also gain energy by collision with other molecules. The temperature of the atmosphere reflects both processes.
  3. Climate Change: The 40 Year Delay Between Cause and Effect
    #25 nerndt Atmoshperic conditions are trivial. Good to know. Glad that's settled. It's really too bad so many climatologists are in the dark on this point. I guess they're just dumb, huh?
  4. Climate Change: The 40 Year Delay Between Cause and Effect
    scaddenp at 10:10 AM, it all comes back to trying to establish how as mentioned in the lead article CO2 "is “tuned” to the wavelengths of infrared (heat)" when it is clear that it absorbs and emits thermal energy at wavelengths beyond that "tuned" range found in the atmosphere. Can you elaborate on your answer as to clarify whether CO2 also absorbs and emits thermal energy at temperatures and pressures BEYOND those found in the atmosphere, and thus is not "tuned" to any specific range.
  5. Climate Change: The 40 Year Delay Between Cause and Effect
    John - answer to 1 and 2 would be "all temperatures and pressures found in the atmosphere. (pressures of 1bar or less). Again, the relevance of your questions to anything in climate is hard to guess.
  6. Climate Change: The 40 Year Delay Between Cause and Effect
    Riccardo at 09:18 AM, can you perhaps clarify these points for me, 1 - at what temperatures does CO2 exist as a gas? 2 - what is the range of temperatures that CO2 absorbs thermal energy and emits thermal energy?
  7. Climate Change: The 40 Year Delay Between Cause and Effect
    johnd, in #28 I copied part of your previous post and said it was not true. Maybe now you agree with me. In #34 you're switching argument: "As the diagram indicates, at 1 bar pressure the absorption band for thermal energy exceeds the range of 200K to 400K, that limitation being solely the range of the diagram." As MichaelM already said, there's no relation between a PT diagram and vibrational absorption/emission. That diagram just tells you that at 1 bar pressure CO2 is a gas between 200 and 400 K. Good to know, but then what? There's no thermal energy nor absorption lines shown there.
  8. A detailed look at Hansen's 1988 projections
    Badger, for the AR5, you are look for PCMDI participants
  9. Climate scientists respond to Monckton's misinformation
    The Guardian still doesn't have a working link to this article. Look, the politicians are getting a lot of money from fossil fuel interests. Cuccinelli's dad used to work in marketing for the American Gas Association and now has two companies that do advertising and marketing--including for "European" companies. Sometimes these "professional services" are just ways of laundering money from foreign entities to US politicians. I have some experience of such "Europeans." They are going to try to destroy the scientists by hiring politicians and lawyers. They are going to take over consumer affairs. That's what they do in the part of "Europe" they come from. They don't care what is true. They want to sell gas.
  10. Climate Change: The 40 Year Delay Between Cause and Effect
    Johnd: The chart at #23 is just a pressure-temperature phase diagram and has nothing to do with IR absorption bands. It indicates at what pressure/temp combination CO2 changes state eg at 10Bar/225K CO2 will be liquid and boil at 230K. The 200/400 limits of tempeature are just what the creator of the diagram chose. It looks like the colored-in version of this.
  11. A detailed look at Hansen's 1988 projections
    Badger, You are welcome. Follow the second link in my post @88 ("more info here").
  12. Climate Change: The 40 Year Delay Between Cause and Effect
    John, no significant change means no cause. Unlike GHG concentrations. As to whether laboratory measurements are born out in the natural world, then I can only point you at the classic Ramanathan and Coakley 1978 paper which tested just that, confirmed by numerous other studies since.
  13. Climate Change: The 40 Year Delay Between Cause and Effect
    Riccardo at 08:20 AM, that is exactly the point I am making. As the diagram indicates, at 1 bar pressure the absorption band for thermal energy exceeds the range of 200K to 400K, that limitation being solely the range of the diagram. For comparison think H2O and the changes of states that occur that affect the absorption and release of thermal energy, and how they relate to the natural environment.
  14. Climate Change: The 40 Year Delay Between Cause and Effect
    scaddenp at 08:04 AM, re "unnatural environment", obviously the laboratory Phil, the properties of CO2 as proven in the laboratory as referenced in the lead article, and illustrated in the diagram posted. Re your second comment, think cause and effect.
  15. Climate Change: The 40 Year Delay Between Cause and Effect
    johnd, I'm making the opposite point, molecular absorption of CO2 (or any other molecule, for that matter) is an intrinsic property of the molecule. Pressure and temperature of the gas only slightly widen and shift the absorption band. Try a google search for pressure and Doppler broadening. In accurate radiative transfer codes the broadening effects are taken into account because the "wings" of the wider emission at higher temperature and pressure near the ground is less absorbed in the upper atmosphere. But these are subtleties.
  16. A detailed look at Hansen's 1988 projections
    BP #72 I'm sorry, but that's really not good enough. Comparing charts by eyeball like that is so ridden with pitfalls of subjectivity (conformation bias, perceptual bias and so on) the only way you can hope to offer a valid comparison is through statistical comparisons. And that's even before accounting for Albatross' comments at #78, which suggests that even if quantified your analysis would be invalid in any case. As I've said previously, if you want to be taken seriously, you've got to do much much better than this in terms of the way you go about assessing the evidence.
  17. Climate Change: The 40 Year Delay Between Cause and Effect
    john, I remain extremely confused by both your posts. "far greater range than found in natural environment". What unnatural environment are you talking about then? That temperature of surface varies with season is hardly surprising, nor is the globally, annually averaged heat capacity of surface materials varying in any significant way on the time scales we are interested in. I fail to see what you are driving at here.
  18. Climate Change: The 40 Year Delay Between Cause and Effect
    Riccardo at 06:44 AM, I think you are making the same point as I was. The properties of CO2 allow it to absorb and radiate thermal energy over a far greater range than what is found in the natural environment, and it is the environment itself that determines the width of the absorption frequency.
  19. A detailed look at Hansen's 1988 projections
    @ Albatross: Thanks for the link to the GISS webpage. Where can I find a laundry list of the current generation of climate models, i.e., the ones that the IPCC will use in the new assessment process now getting underway?
  20. Climate Change: The 40 Year Delay Between Cause and Effect
    CBDunkerson at 06:28 AM, is it not instead that the ocean, and land, heat accumulation that is causing the warmth in the atmosphere. Incoming solar radiation must first be intercepted and absorbed by matter on the surface BEFORE being converted to IR that then transfers into the atmosphere. How near surface temperatures just below the surface vary over the course of a year indicates that at times incoming solar energy is excess of what is being lost into the atmosphere and so is accumulated as thermal energy below the surface, whilst at other times incoming solar radiation is less than that being lost to the atmosphere from below the surface where the thermal energy stored begins to decline.
  21. Climate Change: The 40 Year Delay Between Cause and Effect
    john, "The absorption of IR, being thermal energy, heat, in the atmosphere falls within certain limits due, not to the properties of CO2 [...]" It's not so. First of all, IR is an electromagnetic wave as any other. It is emitted by warm bodies and this is why it is associated to heat. The absorption properties of a molecule depend on the characteristic frequencies of vibration of the molecule which in turn depend on the physical properties of the chemical bond. No relation with temperature here. The environemnt has an impact on the width of the absorption frequency (and very little on the central frequency) but not on it's ability to absorb or radiate EM waves (apart from extreme "pathological" cases which are not relevant to our atmosphere). In short, your claims are physical absurdities.
  22. Hansen's 1988 prediction was wrong
    Ok thanks for clarifying about Scenario C. It still might not hurt to explain in the "Basic" version that: 1) Michaels was misleading by focusing on Scenario A and ignoring Scenario B, and 2) Hansen had less data in 1988 and got the sensitivity wrong, but his overall theory (GHG and temp increases) has been borne out by observations in the last decades. Thanks again for the great post here!
  23. Climate Change: The 40 Year Delay Between Cause and Effect
    #22:"If you meant all CO2 emitted up THROUGH 1970" A cumulative plot using the CDIAC data shows that most of the emissions prior to 1950 or so don't make much of a contribution compared to everything since. See the cumulative graph in the figures here, for example. The caption says "Half of 270 Gtons [the cum to 2000] emitted since 1974". So if we are just now seeing the heating effects of the first half (its ~40 years post 1974) and have yet to see the heating effects of the second half --- ouch!!! For example, arctic ice melt started accelerating in the '80s; was that due to cum CO2 up to the 40's? That's why I'm still having trouble wrapping my head around a 40 year lag.
  24. Climate Change: The 40 Year Delay Between Cause and Effect
    nerndt #25: "Atmoshperic conditions are trivial." This is simply false. Basic physics tells us that without the atmosphere the planet would be about 33 C colder... and thus a solid ball of ice. The amount of heat retained in the atmosphere itself is SMALL (not "trivial") compared to the amount in the oceans, but the atmosphere is CAUSING a great deal of that oceanic heat accumulation.
  25. A detailed look at Hansen's 1988 projections
    #90: "scenario B and C had an ‘El Chichon’ " Yes, angusmac's refurbished graph shows the model runs with a one year dip; Pinatubo (and the LOTI curve) was more like 2-3 years (see Robock 2003). I'd assume there were more model runs and only these 3 made the paper.
  26. Climate Change: The 40 Year Delay Between Cause and Effect
    repsonse to #18 Ned at 02:10 AM on 23 September, 2010 Ned - Of course global warming and cooling occurs, but CO2 has a minimal effect being a small percentage of greenhouse gas effect and that the atmosphere has a minimal effect on the overall energy of the earth (being more than 1/500 of the totla mass). Can anyone here see the big picture? The key point is that mankinds increase of CO2 to the atmosphere pales in comparison to the effects on the oceans and land by other conditions. Atmoshperic conditions are trivial.
    Moderator Response: See the post (and take the discussion there): CO2 effect is weak
  27. Climate Change: The 40 Year Delay Between Cause and Effect
    As for your general idea that since the mass of the ocean is much greater than the mass of the atmosphere, we can safely ignore climate change ... well, that just makes no sense. The mass of the ocean was just as large at the end of the previous interglacial, but that didn't prevent the very radical climate change in which ice sheets spread southward for 80,000 years, eventually covering the place where I now sit with over 2 km of ice. Why would the mere existence of massive oceans prevent us from altering the climate in a similarly dramatic fashion in the opposite direction? That's just wishful thinking, frankly. Hi Ned. The point I was trying to make is that the largest contributor to any global warming is not the atmospher, but the water and land masses. The atmosphere only has 1/500 (or less) overall mass than the oceans and has minimal effect. The one time this may not be the case would be in a large catastrophic event (huge volcano or metror strike) which then changes the absorption of energy by the oceans and land masses and quickly causes climate change.
  28. Climate Change: The 40 Year Delay Between Cause and Effect
    On the point made in the lead article of this topic of CO2 properties as having been established in the laboratory, the behavior in the atmosphere should follow. The absorption of IR, being thermal energy, heat, in the atmosphere falls within certain limits due, not to the properties of CO2, but must be due that of the environment itself as CO2 can absorb heat to temperatures far in excess of normal conditions without any change of state occurring as this chart shows. The ability of it to radiate heat off, transfer heat to other adjacent matter will depend again on the state of the environment rather than any specific property of CO2 given it remains a gas at normal pressures at temperatures well in excess of anything within the normal environment.
  29. Anne van der Bom at 05:43 AM on 23 September 2010
    A detailed look at Hansen's 1988 projections
    muoncounter #79 Actually, scenario B and C had an ‘El Chichon’ sized volcanic eruption in 1995. Pinatubo was much larger (about 4x I believe), so your point is still valid. The only way to deal with this is do multiple model runs, based on different scenarios. The inclusion of one or more volcanic eruptions then becomes part of those scenarios alongside the emissions.
  30. Does Climate Change Really Matter?
    Kevin Judd: “Big storms and extreme weather require a lot of energy to drive them.” Arkadiusz Semczyszak response "Nothing could be further from the truth. Great storms require a considerable variation in energy over a small area." The Ville: Tell us something we don't know Arkadiusz. Since Kevin didn't actually define what a big storm was, I think you are making an assumption and then automatically correcting something without knowing what Kevin was referring to. If you weren't here to be deliberately negative, you would have asked for a clearer definition of what a big storm was and then made a comment on that. Arkadiusz Semczyszak: "...we understand that with the increase of the energy supply to such an system...number of extreme events as a result of warming MUST be reduced." The Ville: By your own definition you are incorrect. You earlier stated "Great storms require a considerable variation in energy over a small area.", not increased or decreased energy. Arkadiusz Semczyszak: "Polish scientists (Natural Disasters, 2008.) write: "In the years 1701-1850, ie during the period when the Earth was in the so-called Little Ice Age in the Caribbean basin hurricanes were almost three times higher than in the second half of last century." The Ville: Sorry, 'Polish scientists' were cherry picking or wildly wrong. See Ricardo García-Herreras work on Spanish records of hurricanes in that area and era. Given that the Polish were no where to be seen as far as Atlantic exploration is concerned, I think Spanish records are probably more accurate. Specifically between 1576 and 1601 there was a huge peak, they then dipped until 1760, then started peaking again. eg. during a large chunk of the 'LIA' there were both larger numbers and fewer.
  31. Climate Change: The 40 Year Delay Between Cause and Effect
    BmuS #17, dana1981's answer is probably the most useful you'll get. If you are really looking for the warming from CO2 emitted in JUST the year 1970 then we are talking about less than 2 ppm and the resulting warming would be exceedingly tiny. If you meant all CO2 emitted up THROUGH 1970 that's a much bigger factor, but difficult to quantify. Let's say CO2 had stabilized at the 1970 level. I think that was around 320 ppm. In that case, assuming a climate sensitivity of 3 for a doubling of CO2, I get; ln(320/280) * (3 / ln(560/280)) = 0.58 C Since we are 40 years past 1970 pretty much all of that warming should have now been cycled through into the atmosphere. Obviously, different climate sensitivity factors would yield different results, but the current 0.8 C warming is consistent with the 3 C 'fast feedback' sensitivity estimate.
  32. Antarctica is gaining ice
    DSL, wow that IS a bit odd. Antarctic sea ice is expected to eventually start declining, but this seems more likely to be some sort of short-term fluctuation. The 'growth' in Antarctic sea ice has been small enough that the current year amount still drops below the long term average semi-regularly. This contrasts with the situation in the Arctic where skeptics got excited earlier this year about the extent coming CLOSE to the long term average for the first time in years. Thus, the current dip is unusual, but not unprecedented. Looks like the Southern melt season started about two weeks early for some reason.
  33. Climate Change: The 40 Year Delay Between Cause and Effect
    beam me up scotty @ #17 - see Quantifying the human contribution to global warming. Short answer, it's approximately 100% over the past 35 years and approximately 80% over the past century.
  34. Antarctica is gaining ice
    Yah, people, when does Antarctic sea ice extent begin to look a little freaky. I don't expect it to continue to nosedive, but I'd like to hear from any experts as to when the dive might/should stop.
  35. Does Climate Change Really Matter?
    I agree with Mr. Judd’s argument. As Matt J. (comment 6) pointed out, 2-3 degrees Celsius is equivalent to 4-6 degrees Fahrenheit. An increase in several degrees might seem minute at first, but one needs to consider the scale upon which we are viewing these changes. Consider the human body for example. Our body’s hold a general temperature of around 98.6 degrees Fahrenheit; with a less than a two degree increase in our body’s core temperature we are classified as having a fever, entering a state of “sickness.” Now I know our bodies are different than the entire world; or, are they really that much different? The nature of the planet we live in is in no way less intricate than the incredible complexity of our bodies; both exist in a delicate balance. Countless systems work together in harmony under an ideal set of conditions. If the conditions in which these systems operate are altered even slightly, the consequences can be exponential. If you have a fever and catch a cold, are you able to operate at your normal day-to-day level? Now consider Earth “catching a cold,” the symptoms of our planet getting sick can be devastating not only now, but for future generations to come.
  36. Climate scientists respond to Monckton's misinformation
    Hi Rob @38, "But Dr. Scott Mandia started it!"-- says the albatross pointing a huge wing at post #22. Seriously though, I think some politicans have borrowed a page from Hollywood-types in terms of antics used to "advance" their careers. Hmm, I have a self imposed deadline to meet and am clearly procrastinating.
  37. Climate scientists respond to Monckton's misinformation
    Albatross... Yeah, I'm sure as soon as John gets up we're both busted. ;-) Sometimes I think we're living in upside down world in US politics today where doing stupid things can actually propel your career.
  38. Climate scientists respond to Monckton's misinformation
    Rob @36, No need to apologise to me, I'm just concerned that we are distracting from the point of the post-- that said, I do now feel obligated to answer questions asked of me. Hope John is not grumpy when he wakes up (; I'm sure that an AG can file a case whenever he or she chooses to (maybe I was not clear on that), but to do so without sufficient grounds is probably not good for one's career ;)
  39. A detailed look at Hansen's 1988 projections
    @angusmac: please re-read my response to this at #55. If you don't understand parts of it, please tell me.
  40. A detailed look at Hansen's 1988 projections
    Badger @83, Maybe this will help. Dana and Tom, What you said :) Current equilibrium climate sensitivity for the GISS model is about 2.7 C. More info here.
  41. Climate scientists respond to Monckton's misinformation
    Albatross... Also sorry if we're going OT. I could be wrong but I think the AG probably can file a case regardless of whether it has grounds or not. And that's what happened. The case was completely without merit and was struck down by the judge. Literally, I think Cuccinelli was just trying to make noise in order to raise his own profile in politics. In that, the case didn't need to have any merit at all. It's just grandstanding for attention. For Cuccinelli it was mission accomplished.
  42. A detailed look at Hansen's 1988 projections
    Tom Dayton - well said.
  43. A detailed look at Hansen's 1988 projections
    Angusmac, You claim, "If the hypothesis is not in good agreement with real world observations then it should be amended until a reasonable agreement is reached." The physics behind GHG forcing is a theory, not a hypothesis. Same holds true for the theory of anthropogenic climate change. The challenging part is getting models to simulate the complex climate system on the planet, and then seeing how the system responds to changes in internal and external forcing mechanisms. Models are wonderful resources b/c they permit one to undertake carefully planned experiments, and that is what Hansen et al. tackled in 1988. How might the climate system respond to increasing radiative forcing from GHGs? The 1988 paper was seminal, but as is often the case for seminal works, it was imperfect-- and Hansen et al. fully realized that much. The science (and models) has advanced since then...it seems it is only the skeptics who are stuck in 1988. It was through a combination of huge leaps in computing resources, better code, and by considering new data and advances in the science that modelers have been able to dramatically improve the models. The new generation of AOGCMs even include atmospheric chemistry. While the model in 1988 was imperfect, it certainly was not nearly as imperfect as some contrarians have elected to falsely state on the public record. That is what this whole post is about-- I really cannot understand why some people cannot see that. So Angus, you have the wrong end of the stick when you and others keep claiming that keep claiming that it is the scientists who are stuck in the past and not moving on. What you are complaining about in the quote (that I cited above) is actually exactly what scientists continue to strive towards. PS: Are you familiar with the Earth Simulator 2 project in Japan?
  44. A detailed look at Hansen's 1988 projections
    angusmac - yes, you're missing about 90% of my article. The issue has been amended. We don't currently believe that 4.2°C is the correct short-term climate sensitivity for 2xCO2, we believe it's around 3°C, which is confirmed by comparing Hansen's results to reality. I'd really prefer not to have to repeat this for a sixth time. Scenario C is irrelevant. It's "on the money" because its' a combination of a too-low forcing and a too-high sensitivity. Saying C is on the money is like saying if I go twice the speed limit and then half the speed limit, I was going the right speed the whole time.
  45. A detailed look at Hansen's 1988 projections
    angusmac, the "hypothesis" has been amended--considerably! The models currently "use" a sensitivity lower than the one Hansen used. I put "use" in quotes because the models do not take the sensitivity as an input; the net effect of all the factors in the models is summarizable as a sensitivity. But those amendments were not made simply as a reaction to the mis-prediction of the original model. Instead, the models started to be improved long before any meaningful evaluation of the accuracy of Hansen's prediction could be done. The improvements continue to be made to the underlying physics of the models. The "hypothesis" that is most important is that temperatures were predicted to rise, and have, as opposed to being unchanged or dropping. Less important is the exact rate of rise. Of course the rate is important, which is why research continues urgently.
  46. A detailed look at Hansen's 1988 projections
    I presume that Dr, Hansen and his team have maintained a log of changes they have made to the forecasting model they used in 1998. Is the log in the public domain?
  47. A detailed look at Hansen's 1988 projections
    angusmac writes: If the hypothesis is not in good agreement with real world observations then it should be amended until a reasonable agreement is reached. Yes. And as dana1981 has repeatedly pointed out, the "hypothesis" here is basically that temperature would rise at a rate corresponding to a climate sensitivity of 4.2C per doubling of CO2. The observed trend suggests that this is too high, and that a value of 3.4C per doubling would be a better fit. Can we all agree on this? FWIW, 3.4C/doubling falls nicely within the IPCC's estimated range for climate sensitivity.
  48. A detailed look at Hansen's 1988 projections
    In the context of this discussion thread and the one associated with the article about Dr. Roger Pielke Sr’s pronouncements about OHC, I have a question. Are any of the current crop of climate models designed to forecastof how the heat content of the sub-systems comprising the climate will change under different GHG forcing scenarios?
  49. Climate scientists respond to Monckton's misinformation
    Rob @34, I fear that John might edit this as it is OT, but I want to clarify something before letting everyone move on. The Virginia AG did not have grounds to investigate Mann, nor was it a legitimate action-- he was clearly on a witch hunt and fishing for something. In contrast, committing perjury is actionable and there is compelling and legitimate evidence to make that case here.
  50. A detailed look at Hansen's 1988 projections
    Dana1981, am I missing something here? My contention is quite simple: real world emissions are following Scenario B whilst real world temperatures are following Scenario C. I thought that real (sceptical) science was about making observations, postulating a hypothesis and testing that hypothesis against the real world. If the hypothesis is not in good agreement with real world observations then it should be amended until a reasonable agreement is reached. Currently the hypothesis which supports Scenario B is not in good agreement with real world temperature measurements. Therefore it is either a poor hypothesis at best or it is incorrect at worst. Either way it should be amended. Hansen 2005 stated that Scenario B "was on the money." Now it looks as though Scenario C "is on the money." Consequently, if real world trends continue to follow Scenario C then computer model forcing and consequential temperature increases should be revised downwards to match real world observations.

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