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Comments 75651 to 75700:

  1. Dessler Demolishes Three Crucial 'Skeptic' Myths
    It may be that "It's difficult to exaggerate the impact of Dessler's findings". But it is always wise to show a little caution until the findings are robust. Dessler's paper DO show that SB and LC have serious problems. But it is also POSSIBLE at this stage that Desslers' paper also may contain some problems. If it does, then this post may be a little too reliant on the one paper. Also, in my view, comments here are much more valuable if they tone down the mocking and the personal and concentrate on the science and a more "neutral" language. A science blog this is. That said, keep up the good work. Lots of objective and valuable information on this site.
  2. Medieval Warm Period was warmer
    Thanks a lot folks, I love learning about all this stuff
    Response:

    [DB] In addition to using the omnipresent Search function in the upper left corner of every page here, one can also examine skeptic arguments by Taxonomy.  However, much information is contained in blog post form here which may not be found in the rebuttals, so the search function is best overall.

    For example, a search of the term "Medieval Warm Period" returns the following:

    Search Results

    Skeptic arguments matching the search 'Medieval Warm Period':

    Blog posts matching the search 'Medieval Warm Period':

  3. Dessler Demolishes Three Crucial 'Skeptic' Myths
    XKCD's racecar on a train cartoon is a brilliant take on D-Kish style occurences. The alt-text would offer the perfect self-test for anyone like Spencer willing to actually abide by it: I mean, what's more likely -- that I have uncovered fundamental flaws in this field that no one in it has ever thought about, or that I need to read a little more? Hint: it's the one that involves less work.
  4. Medieval Warm Period was warmer
    #34 Tristan: The difficulty skeptics have with the MWP (MCA) is that they've heard all this anecdotal evidence of NW Europe being warmer, or Greenland being particularly pleasant for the Vikings (less unpleasant would be more appropriate), and they conflate that with the idea that therefore the whole world must have been uniformly much warmer during the MCA. To our best knowledge (see scaddenp's link), warming wasn't uniform, either in space or in time, and so globally it was relatively modest. Some places were warmer, others cooler or not much different. IIRC, Greenland's peak warmth occurs a couple of hundred years before Britain or Central Europe experienced peak warmth. At the same time, other areas were cooler and so global temperature just wasn't as much warmer as some skeptics would like to believe, see Mann et al 2009. The Little Ice Age experienced similar variations, in that it's most pronounced over NW Europe and the N Atlantic region, driven most likely by some increased volcanic activity and reduced solar activity. Where do most of our familiar cultural / historical records of the Western world emanate? NW Europe, hence at least part of the entrenchment of the MWP/LIA ideas. Today's warming is (relatively) much more globally uniform by comparison, and so there's much more of a signal in global mean temperature. Our best idea of climate forcings over these periods (solar/volcanic activity, then the recent CO2 spike) reflect these global patterns. The overall pattern globally is one of relatively subdued changes over the MWP/LIA, then a large rise through the present, reflecting the forcings. Skeptics complain about the 'missing MWP' because they want it to be there, large and proud, in global temperature records. The evidence suggests that it's only large and proud in some parts of the world, some of the time, disappointing the skeptics... again. Oh, and if that palaeo evidence were to be overturned and the MWP was globally really strong, what is the main implication? Very high climate sensitivity, not what skeptics want to hear!
  5. Dikran Marsupial at 17:43 PM on 8 September 2011
    CO2 is just a trace gas
    Dan69 wrote: "That being said, my understanding is that the Lagrangian math works great for 2 points, but becomes infinitely complex when you add 3 or more points to the equation." I think you are referring to the N-body problem there, which is a different problem (as for the double pendulum there is a physical constraint on the distance between hinges. Also for the double pendulum, from what I have read the Lagrangian is used to set up the differential equations which are then solved numerically. If there was an analytic solution (i) it wouldn't be a chaotic system and (ii) the programmers would have used it. For General Circulation Models, the techniques used are essentially those developed for fluid dynamics, and work very well in a wide range of other applications, the apparent complexity of the problem is not as big an issue as you might think (GCMs don't work by predicting weather, but by simulating weather with statistically similar properties). So the N-body problem has very little to do with either double pendulums (pendula?) or climate modelling. "The only point I see is in the politics of controlling output of man-made CO2 as the primary focus on policy, not the truth behind what is actually going on with the climate." It is perfectly appropriate for policy to be focussed on controling carbon emissions. CO2 is not the only forcing, but it is an important forcing and the one that we have been using substantially since the start of the industrial revolution. We can't legislate about solar forcing, the Sun isn't subject to policy; carbon emitters are. The truth behind what is actually going on with the climate is well set out in the IPCC WG1 Scientific Basis. To a first approximation, the summary for policy makers is essentially "anthropogenic carbon emissions will cause global surface tempetratures to rise significantly over the next century; if you don't want that (and the resulting impacts) to happen, then we need to stabilise atmospheric CO2". "Clearly,climate is a complex ball of wax and suppressing one part, without a full understanding of the unseen consequences, would have possibly worse outcomes." Nobody is suppressing anything. As I pointed out earlier, "skeptics" (note the use of "") frequently claim climatologists are suppressing something, or they don't know about something, or that they know about something but pretend it doesn't exist. However that doesn't make it true and simply reading the IPCC WG1 report demonstrates that generally it isn't true. However that doesn't stop the gullible from swallowing it hook line and sinker. Secondly, it is impossible to have a full understanding of anything regarding the real world, we can only have imperfect or uncertain knowledge. We have know this since the work of David Hume. Following your logic we would never be able to draw conclusions about anything or plan our actions. However there is a thing called "statistical decision theory" which provides a provably optimal way of planning under uncertainty, which is what rational people do. "I also defer to Quine-Duhem theory with regards to the unknown variables present." I had to look that one up. Essentially it says that hypothesis testing is always subject to assumptions, something that all scientists know. However mostly those assumptions remain unsaid as they are part of the dominant scientific paradigm of the day. However it is not a reason to ignore the results of the hypothesis test. There is always residual doubt over the truth of any physical proposition, but it would be absurd to use that residual doubt as a reason not to act when the balance of the evidence suggests that action is required. Lastly, I think there is a radiative competent as to the upper limits of what CO2 can affect. " ISTR going over this recently. The radiative forcing from CO2 is logarithmic in the concentration, so no, there is no limit as the limit of log(x) as x tends to infinity goes to infinity.
  6. Medieval Warm Period was warmer
    Tristan - I doubt facts would have much influence skeptics pushing this argument but you can see these at the paleoclimate chapter in the IPCC report, specifically this section for temperature reconstructions and model simulations of this period. However, more recent work has shown the MWP (better called MCA) to be rather more complex than simple global event (see this paper for instance) so appears a dynamical component involved as well.
  7. Medieval Warm Period was warmer
    Apologies in advance if I've failed to find it, sometimes I have trouble navigating this site: I keep hearing from the skeptic corner that the MWP isn't reflected by any of the IPCC's models and therefore the models are completely useless. Is there a page that examines this issue?
  8. Pete Dunkelberg at 14:45 PM on 8 September 2011
    Tar Sands Impact on Climate Change
    What about the rhetoric of rejection? "Nothing matters, it will all be developed anyway. Atmospheric CO2 will probably go up to 1000 ppm and human population plummet no matter what anyone does." Some people think human action matters. This pipeline is symbolic of whether we start heading off 1000 ppm now or wait until after CO2 reaches 450. If we stop the pipeline and start heading in the right direction and show some leadership all of a sudden, it is not at all certain that all the tar will be burned. Stopping it or not will be symbolic in addition to the direct effect on barrels burned. Symbols matter.
  9. Pete Dunkelberg at 14:34 PM on 8 September 2011
    Tar Sands Impact on Climate Change
    This article: http://www.tarsandsaction.org/signup/dechristopher-share/key-facts/ will make you not want this pipeline. For starters:
    * Keystone XL is an export pipeline. According to presentations to investors, Gulf Coast refiners plan to refine the cheap Canadian crude supplied by the pipeline into diesel and other products for export to Europe and Latin America. Proceeds from these exports are earned tax-free. Much of the fuel refined from the pipeline’s heavy crude oil will never reach U.S. drivers’ tanks.
  10. The human fingerprint in the daily cycle
    139, Norman, I hadn't realized that you'd supplied that same link. I found it later for an entirely different purpose, when trying to google "atmospheric temperature altitude hour" to try to determine if there's any observational evidence of how the atmosphere warms or cools through the day... although I'm sure I must have looked at it when you sent it. I did find the paper you referenced. Here is the link. I'll have to read it. It looks interesting. Briefly parsing the section you quoted, it does not seem to have an obvious impact on DTR. It seems instead to be arguing for a factor in lower climate sensitivity (i.e. that a warmer atmosphere has an enhanced ability to "pass through" additional heat coming from the surface). But it clearly complicates the picture I've painted and warrants reading. FYI, this link is to a PDF for what appears to be a slideshow on the same subject by the same author (Huang). This seems to be a favorite topic of his. Searching for "Planck damping" and "Planck effect" primarily yield papers by Yi Huang, including his dissertation.
    Response:

    [DB] Fixed link.

  11. Republican Presidential Candidates vs. Climate Science
    @KR #99: The articles that I provide links to further amplify and reinforce the quotes provided by Dana in his article.
  12. The human fingerprint in the daily cycle
    Sphaerica @ 138 Thank you for your thoughtful and intelligent posts in response to my posts. I am not sure if you are playing with me or not, you page link in this post is the same one I linked to in post 115. I did find this article that explains why DLR is reduced during the day. I guess a warming atmposphere effects the way radiation is absorbed. Quote from article: "It is interesting and very important to note that the negative temperature dependence of water vapor continuum absorption has a contrasting effect on DLR. When warming occurs at the surface and consequently in the atmosphere, this mechanism enables more emission from the surface to leave the atmospheresurface system and simultaneously reduces the downward radiation from the atmosphere to the surface. This would tend to lower the warming at the surface. Further, this mechanism is strongly sensitive to the concentration of lower tropospheric water vapor. With increased moisture in a warmer climate, the negative temperature dependence of the continuum absorption is likely to play a more prominent role. It will make the Planck effect more efficient in damping the warming of the atmosphere-surface system, and will also reduce the radiation emitted to the surface from a warmer atmosphere." I like the intelligence found on this site, it is food for thought and research. Sorry Sphaerica I can't link directly to the article. It loads as an adobe file directly. If you want to look at the article then it is the first search in Google with this search words "atmpospheric temperature effect on DLR" Have a good day!
  13. Dessler Demolishes Three Crucial 'Skeptic' Myths
    John @9 It would most closely be identified with narcissistic personality, where an individual has an exceedingly inflated self-opinion that cannot be substantiated by the evidence. The person instead seeks to create and perpetuate assorted rationalizations justifying their grandiosity, while minimizing the conclusions one would arrive at with more objective measures. Not that I personally have any idea if this is how Roy Spencer actually operates - I don't pay enough attention to alleged "science" that you primarily only find on political media outlets. However, such an individual could easily be manipulated into supporting private political causes if the desired conclusions appeal to said narcissist's need for self-flattery.
  14. Andrew Dessler's New Paper Debunks Both Roy Spencer And Richard Lindzen
    Joshua Hill over at PlanetSave included a brief You Tube video by Dressler in his post of yesterday (Sep 6) “Clouds Do Not Cause Climate Change.” Perhaps one of the moderators with more technical expertise than I could import that video onto this comment thread -- or perhaps incorporate it into the article itself.
    Moderator Response:

    [DB] Embedded video in the OP at the end.

  15. Dessler Demolishes Three Crucial 'Skeptic' Myths
    Joshua Hill over at PlanetSave included a brief You Tube video by Dressler in his post of yesterday (Sep 6) “Clouds Do Not Cause Climate Change.” Perhaps one of the moderators with more technical expertise than I could import that video onto this comment thread -- or perhaps incorporate it into the article itself.
    Response:

    [DB] Embedded video at the end of the OP.

  16. Dessler Demolishes Three Crucial 'Skeptic' Myths
    Isn't Spencer's attitude rather like that of Monckton, who frequently uses the phrase that the science -- that is, his version of the science -- is "...blindingly obvious"? I suspect that there is a personality type -- or perhaps mental aberration? -- that succumbs to Dunning-Kruger and it would be interesting for someone with psychiatric qualifications to define exactly what the characteristics are. I suspect it lies behind quite a few people in climate denial who clearly think they understand the science better than the acknowledged experts.
  17. CO2 is just a trace gas
    Dan69: To add to Dikran's excellent response, you need to remember that though CO2 is present in small quantities, for radiative forcing it's the initial small quantities that are the most important radiatively. See Chris Colose: Greenhouse Effect Revisited on the subject, where you can see that the 'bite' CO2 takes out of the longwave spectrum is already significant at just 2ppm, and large at 50ppm. It continues to grow, increasing its effect by the same amount each time CO2 doubles. The lines keep broadening as concentration increases, so the effect does not 'saturate'. I often wonder how the climate issue would have played out on a hypothetical Earth, sat a bit closer to the Sun, but with only about 50ppm CO2 in the pre-industrial atmosphere. On the hypothetical Earth, which would be much more (too much, most likely) sensitive to increases in CO2, our Industrial Revolution to present would have produced two whole doublings of CO2 concentration. The transient sensitivity would be something like 4C. I'm not sure there would be much argument as to cause on such an Earth, as the change would be frightening! I'd also highly recommend the Alley lecture - beautiful science communication.
  18. Models are unreliable
    Tristan if you want to play with simple phenomenological model with say multiple regression, then have a look at Benestad and Schmidt 2009 for an example. Sunspot number is very crude - you should use one of latest TSI proxy constructions (eg look at here. Very importantly though, you need an aerosol term, both industrial and volcano. For internal variability, you should include an ENSO index.
  19. Dessler Demolishes Three Crucial 'Skeptic' Myths
    Spencer's efforts to defend his paper have thus far been quite poor, failing to address most of Dessler's criticisms, or to admit any fault. Barry Bickmore had a good rundown.
  20. Andrew Dessler's New Paper Debunks Both Roy Spencer And Richard Lindzen
    Spencer's WUWT post is just a re-post of the poor defense of his paper on his own blog. In it he fails to explain why he omitted 8 of the climate model runs (including the ones which best matched the data), why he chose the observational data set which maximized the model-data discrepancy, why he failed to include error bars, etc. Basically the only of Dessler's points against his paper he addressed was the ocean heat transport to cloud TOA flux change ratio (Dessler's 20:1). Spencer claims it's closer to 2:1, but commenters on his blog have already identified some errors in Spencer's calculation. It's also ironic that Spencer criticizes Dessler for supposedly not using the "best" data, when Spencer didn't even attempt the calculation in his own paper.
  21. Dessler Demolishes Three Crucial 'Skeptic' Myths
    "It's almost like Spencer's "mad at" [edited inflammatory language] the climate science community " Uh, you reversed the meaning, dude. Try "angered" the climate science community if you don't like the original.
    Moderator Response: [Albatross] Mea culpa. Corrected.
  22. Republican Presidential Candidates vs. Climate Science
    Badgersouth - I understand, but please, state why these links are relevant. I believe that's part of the Comments Policy, under link or pic only.
  23. Andrew Dessler's New Paper Debunks Both Roy Spencer And Richard Lindzen
    KR @60 The fact that Spencer is using an anti-science web site to try and defend his scientific integrity is incredibly ironic, and desperate to boot. It also shows that Spencer is interested in influencing as many misguided, uninformed and gullible minds as possible-- he is engaging in propaganda.
  24. Andrew Dessler's New Paper Debunks Both Roy Spencer And Richard Lindzen
    Roy Spencer posted on WUWT defending his work re: Dessler, albeit not too well in my opinion. I asked why he didn't show the other 8 models he ran (the ones that, you know, didn't disagree with the temperature data as much as the 6 he did show), and whether or not he had some physical mechanism postulated that could cause cloud coverage to vary consistently and over a climate relevant (>10 years) period +/- from the temperature driven water vapor cycle. I noted that he really did not do himself any favors by selecting only the strongest evidence for his hypothesis, despite running multiple models. Waiting to see if he actually responds to my questions...
  25. Dessler Demolishes Three Crucial 'Skeptic' Myths
    Dana @5, What you say is true, but is appear to not apply to those (like Spencer) afflicted with Dunning-Kruger. I know that you know that, but readers here may not be familiar with D-K.
  26. OA not OK part 20: SUMMARY 2/2
    The cannonical reference is Orr, J. C., V. J. Fabry, O. Aumont, et al. (2005). Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437(7059): 681-686. But AR4 and the IPCC 2009 Compendium have more recent refernces.
  27. CO2 is just a trace gas
    Dan69 @ 53... That same Richard Alley lecture does a good job of explaining what is called the "carbonate rock weathering thermostat." It's really very fascinating and well worth taking time to watch.
  28. Dessler Demolishes Three Crucial 'Skeptic' Myths
    Spencer has for a long time been saying on his blog that the rest of the climate science community just doesn't "get it," because what he's doing isn't that complicated. What Spencer seems unwilling to consider is that it's not that other scientists don't "get it," it's that he's making mistakes which invalidate his conclusions. Dessler's point that given Spencer's history of making these grandiose claims based on big mistakes (i.e. claiming the atmosphere wasn't warming until RSS corrected the UAH data analysis), his first thought should probably be "am I making mistakes again?". Really anytime you're making grandiose claims about reversing a long standing body of scientific evidence, your first consideration should be "am I making a mistake somewhere?". But it's especially true when you have a history of such grandiose claims, based on a history of mistakes.
  29. Republican Presidential Candidates vs. Climate Science
    Rick Perry's EPA would be a horse of another color. "I'll tell you one thing: The EPA officials we have an opportunity to put in place, they're going to be pro-business, and there's not going to be any apologies to anybody about it," he said. "Those agencies won't know what hit 'em." I hear the ex CEO of BP needs a job. After all, that little oil spill was a natural event.
  30. CO2 is just a trace gas
    Dikran: Here's an applet for a double pendulum; here's an electrical analog. As you can see from the graphs, some chaotic systems are quite periodic and therefore predictable - and should model quite well, although you might need a bigger computer.
  31. Republican Presidential Candidates vs. Climate Science
    "The economic downturn has made addressing climate change less urgent for voters. But the issue is not going away. The nation badly needs a candidate with a coherent, disciplined national strategy. So far, there is no Republican who fits that description." This is the concluding paragraph of a "must read" editorial, "In the Land of Denial " written by the NY Times Editorial Board and published on Sep 6, 2011.
  32. CO2 is just a trace gas
    Dan69: "Also, I am glad to see you mention that CO2 doesn't control the climate." That's not a good representation of the situation. Say rather that CO2 is an integral part of the current atmospheric dynamic. Removing it causes radical changes to global temp and the current biosphere. Here's the abstract from Lacis et al. 2010 ("Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature" in Science):
    Ample physical evidence shows that carbon dioxide (CO2) is the single most important climate-relevant greenhouse gas in Earth’s atmosphere. This is because CO2, like ozone, N2O, CH4, and chlorofluorocarbons, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can and does. Noncondensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect, thus serve to provide the stable temperature structure that sustains the current levels of atmospheric water vapor and clouds via feedback processes that account for the remaining 75% of the greenhouse effect. Without the radiative forcing supplied by CO2 and the other noncondensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state.
    (bold mine)
  33. Dessler Demolishes Three Crucial 'Skeptic' Myths
    dana1981: "Ouch." It's almost like Spencer's "angered" [edited inflammatory language] the climate science community by saying essentially that either 1) he's smarter than everyone else or 2) since his "revelations" are so obvious, everyone else is in on the Grand Conspiracy. Almost? :) :)
    Moderator Response: [Albatross] Please tone down the language a notch.
  34. Republican Presidential Candidates vs. Climate Science
    @KR #95: The context for the links that I am providing is the article itself. When I see something that I blelieve provides additional/updated information, I post a link to it.
  35. Dessler Demolishes Three Crucial 'Skeptic' Myths
    From the Scientific American interview:
    "You would think, if you have a scientific history of being wrong on so many issues, you would have a little bit of humility before claiming you've overturned scientific evidence yet again," Dessler said."
    Ouch. But a good point.
  36. CO2 is just a trace gas
    Dikran, Thank you for the response. It did teach me something and for that I appreciate it. I am looking to actually learn the issue, and not simply argue my bias. That being said, my understanding is that the Lagrangian math works great for 2 points, but becomes infinitely complex when you add 3 or more points to the equation. Maybe I am wrong here. Also, I am glad to see you mention that CO2 doesn't control the climate. The only point I see is in the politics of controlling output of man-made CO2 as the primary focus on policy, not the truth behind what is actually going on with the climate. Clearly,climate is a complex ball of wax and suppressing one part, without a full understanding of the unseen consequences, would have possibly worse outcomes. I also defer to Quine-Duhem theory with regards to the unknown variables present. Lastly, I think there is a radiative competent as to the upper limits of what CO2 can affect. For example my understanding is the TOA radiates at a constant 240W/m2 and energy radiated up from the earth’s surface is 396W/m2. There is a difference of 156/m2 . Does the introduction of more CO2 have an impact on this?
    Moderator Response: See CO2 effect is saturated.
  37. Dessler Demolishes Three Crucial 'Skeptic' Myths
    Scientific American weighs in. Sadly, and tellingly, Spencer will interpret this as some kind of proof that there is a grand conspiracy to suppress his genius.
  38. CO2 is just a trace gas
    48, Dikran, All you need to know is here. This was the best of the bunch I looked at. The source code is here. You could even just try to modify this to add an attractor to one side of the pendulum, reducing your work load considerably. You'd also want to change the graph to draw the actual position of the lower pendulum, rather than the angle or velocity options currently offered.
  39. CO2 is just a trace gas
    50, Rob, 48, Dikran, FYI, I had the same thought and did some quick googling for the Java app used to draw his animation. I didn't find exactly that one. There are some existing apps to base this on, but it wouldn't be a trivial thing to do from what I can see. One might even need to be written from scratch, although the mathematics behind it is laid out on several different web pages on the subject. It would use up a fair chunk of time to do, though. It is tempting to come up with a JavaScript version to embed in a web page, though, perhaps using GWT to implement it.
  40. Dessler Demolishes Three Crucial 'Skeptic' Myths
    I had exactly the same feelings when I was reading Dessler's paper: this guy has just smashed every single argument used by climate skeptics into smithereens. And it only took him about 5 pages to do it. For me, it was the observational data on TOA flux being more than 20x smaller than ocean heat fluxes. So obvious, yet so totally devastating.
  41. CO2 is just a trace gas
    Dirkran @ 48... That really would be cool if you could model the pendulum exactly the way you've said with outside forcings. Add a couple of little knobs so the user could interact with the forcings. It would be a great learning tool for people who want to better understand the dynamics of climate systems.
  42. Republican Presidential Candidates vs. Climate Science
    Badgersouth - Um, no insult intended, but could you please provide some context for the links you have been posting? For example, why it might be interesting, or what it discusses? I have to admit that I have followed exactly none of your links, as they lack said context.
  43. Andrew Dessler's New Paper Debunks Both Roy Spencer And Richard Lindzen
    The first sentence of the article contains one too many "the"'s.
  44. CO2 is just a trace gas
    Dikran @48, I just wanted to compliment you on your post. That was fantastic-- it could (should) perhaps even be expanded into its own blog post IMHO.
    Moderator Response: [Dikran Marsupial] Cheers! Sorting out a blog post is on my to-do list (I have used the double pendulum analogy before), but I need to learn about Lagrangian dynamics so I can write the applet!
  45. Dikran Marsupial at 02:44 AM on 8 September 2011
    CO2 is just a trace gas
    Dan69 wrote "we are simply scratching our heads and wondering why such a dynamic, non-linear chaotic system rises and falls on one minor gas?" It doesn't (and nobody claims it does, "skeptics" claim that the climatologists claim it does, but that doesn't make it true, try reading the IPCC WG1 scientific basis report for example). Consider a double pendulum, like this one borrowed from wikipedia Thsi is a dynamic non-linear chaotic system. Now imagine putting an electromagnet to one side which can attract the pendulum, which happens to be made of iron. If you turn up the current passing through the electromagnet, the pendulum will still swing back and forth as before, but it will be biased towards the side the electromagnet is placed. Turn the current down again and the pendulum will be centered on average back in the middle. This is a simple analogy for the climate. It has internal variability (the weather, ENSO etc) represented by the chaotic oscillation of the pendulum, and it has forcings such as CO2, aerosols, solar etc (represented by the electromagnet), which bias the oscillations a bit up or a bit down depending on how strong the forcing is (how much current is applied to the electromagnet). The difference lies in the specific details, but the underlying concepts are essentially the same. Juts because weather is chaotic, that doesn't mean climate (long term statistical behaviour of the weather) is also chaotic. Ask yourself why we don't seem to have a runaway thermal affect due to this increase of CO2 alone? Most of us here have never needed to ask such questions becuase it is based on the incorrect assumption that anybody thinks CO2 alone controls the climate. The Stephan-Bolzmann law is one reason. "Also, it seems that the CO2 being a trace gas is never affected by convection. " Can you provide some evidence to support that premise? I rather doubt it as it is quite obviously false (ask yourself how CO2, which is heavier than normal air is well mixed in the atmosphere, vertically as well as horizontally).
  46. CO2 is just a trace gas
    Dan69... "Ask yourself why we don't seem to have a runaway thermal affect due to this increase of CO2 alone?" Think of it this way... When you put one more blanket on your bed on a cold night why don't you get a runaway thermal effect? It's works the same with CO2.
  47. CO2 is just a trace gas
    Dan69 my impression is that there's some misunderstanding. For example, who is claiming that CO2 is not a trace gas? The point of this post is that the concentration of a trace element matters. Another example, who is assuming no convection and a grey atmosphere? One may sometime use highly simplified models to easily show some foundamental behaviour, but radiative-convective models has been developed in the '60s, almost fifty years ago. Your claim is simply untrue, due to a misunderstanding or a lack of knowledge of the matter. If any weakness will be found in our current understanding of the climate system, be sure it won't be on the radiative properties of CO2 or any other foundamental aspect of this well know atmospheric physics.
  48. CO2 is just a trace gas
    Dan69... Reading through your comments it looks to me you're basing your thinking on a lot of assumptions. I would highly suggest you watch an online AGU lecture by Dr Richard Alley called "The Biggest Control Knob." If you google his name and that title it should pop up. CO2's role in moderating the climate system over time is really pretty well understood, so laying MOST (not ALL) at the doorstep of CO2 is not unreasonable. Note though, that no climate scientist says that it's all about CO2. As the Alley lecture title suggests, CO2 is merely the biggest control knob on climate. This is well accepted and backed up by many thousands of research papers. The point to this article is to say to people, yes, trace amounts of things can and do obviously have profound effects. CO2's affect on climate is merely one of the many. If you get through Alley's lecture I would also suggest you spend some time reading the many articles here at SkS. Everything is backed up with published literature so you don't even have to take any given authors word on faith. You are welcome to look at the actual research and make up your own mind if the scientific community is getting it right.
    Response:

    [DB] Alley's talk can be found here.

  49. Republican Presidential Candidates vs. Climate Science
    The study cited in my previous post (#93) is also the topic of "Survey: Tea Party Isolated on Climate, But Wide Accord on Most Energy Policies," a post by Andrew Revkin on DOT Earth, NY Times, Sep 7, 2011. Revkin concludes his post with this ominous warning: "In reviewing the study, I found myself mulling the Tea Party views above in the context of recent research at Rensselaer Polytechnic Institute concluding that when 10 percent of the population holds an unshakable belief, that belief will always be adopted by the majority of the society. "Add in a big dose of talk radio and attack blogs, our habit of conducting politics from the fringes, and the Republican nomination process, then have a look around."
  50. CO2 is just a trace gas
    Let me state up front I am not a scientist, so my comments are based on a layman's view of the issue. CO2 IS a trace gas with regards to overall content of the atmosphere. The rebuttal used, is to compare aspects of trace elements that have an impact on a closed system, i.e. a persons body. Comparing a closed system to an open system to make your point only allows that much skepticism to rests its head on. Whilst they seem to make good rhetoric, they do NOTHING to support your contention that CO2 is in by itself NOT a trace gas. Conflating false examples does not make for an effective argument. Furthermore, please keep in mind that a skeptic on this issue is not debating the physics of the greenhouse-gas theory, or that a slowing in cooling attributed to the 2nd law isn't happening with more CO2 in the atmosphere, we are simply scratching our heads and wondering why such a dynamic, non-linear chaotic system rises and falls on one minor gas? Negative feedback anyone? This doesn't mean that the climate isn't in a warming phase, or disparate behaviors aren't affecting the climate as a whole, but to place it ALL at the doorstep of CO2 seems a leap. Ask yourself why we don't seem to have a runaway thermal affect due to this increase of CO2 alone? IMHO.... Also, it seems that the CO2 being a trace gas is never affected by convection. How can a theory which assumes no convection and a "grey atmosphere" (=no change in absorption properties with wavelength) can be used to explain something significant about the real atmosphere?

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