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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 54551 to 54600:

  1. A detailed look at climate sensitivity
    Michael, thanks for the challenge. I don't think "1C is reasonable" but it is plausible. As I explained here and previously, the apparent probability density functions are not actually PDFs but model run density functions. The choice of ranges of parameters to mimic natural variation determines the shape of the distribution. So I don't think it is reasonable to point to the center of "model density distribution functions" and claim that 3C is reasonable. The fundamental problem is sub-grid scale physical parameterizations which determine the density function, not reality or even simulated reality. More apropos to my previous post is that the paleo bars do not have any density function because there is really no way to know the distribution due to a lot of measurement error, localized measurements (ice cores) rather than global, changes in geography with large unknown effects, etc. One way to deal with some of the unknowns is by using models (e.g. feeding changed geography into the models). The full chart from Knutti and Hegerl is reproduced in post 72 above. It shows that the paleo estimates do not have a similar base state (far left red square in 3b) and do not have similar feedbacks and timescales (next red square). Those two red squares make the model estimates inapplicable to today's climate. To make them applicable, one must remove the uncertainties due to difficult-to-measure feedbacks. The result, at least in K&H08, is that the estimates of sensitivity from paleo data do not have a distribution, they could be uniform or more likely skewed left since other feedbacks also amplified the warming from glacial to current interglacial along with CO2. Today those other feedbacks are missing (e.g. dust, large weather changes, etc) As I said in the other thread there may be new positive feedbacks that were not in play in the glacial transition so that adds uncertainty on the high side.
  2. A vivid demonstration of knee-jerk science rejection
    Thanks for the in depth explanation chriskoz, though I think there is a simpler underlying psychological process going on here. Eric views himself as a rational skeptic, and would be embarrassed to get lumped in with the standard denialist crowd. Hence, he claims that he accepts the 97% scientific consensus. EXCEPT. Except that he won't until some arbitrary milepost of his own specification is met, which it wont be, at least for a decade or two. This allows him to present himself as rational, sane and objective, while still denying the consensus for the next 10 to 20 years. A denier in denial. Nice Work! Self contradiction appears also to be necessary for an accomplished denialist: http://www.skepticalscience.com/plimervsplimer.php
  3. A vivid demonstration of knee-jerk science rejection
    52, chuck101. You didn't miss anything. It's "focused denial" dressed up as rational skepticism.
  4. A vivid demonstration of knee-jerk science rejection
    chuck101@52 You got it essentially right. Furthermore, if you follow the link in JohnMashey@43, you better understand the differences between the problems answered by weather vs. climate simulations. The problems of climate (the changes in the average state of chaotic processes) prediction is not limitted by model accuracy in representing the chaotic processes. What is important is getting the roundings correct (e.g. to have constant mass and energy balance) and the model stability within given boundaries in accordance with observations. Accurate representation of the dynamics of the chaos is less important. As an example, Eric wants the models to calculate dynamic convections to have faith that cloud feedback is well represented. I argue that such calculations, apart from increasing the complexity and be source of potential bugs, may not increase models' reliability more than simple parametrisation tuned with observations would do. Eric displays a typical skeptisism of a weatherman: lack of confidence in simple science about average conditions, because he's an acclaimed expert in underlying dynmical models. A simplified analogy would be: to figure out the average properties of some gas in a container, an expert weatherman might ponder about (or even calculate) the resulting fluid motions, but I don't want to go into such details: simple laws of thermodynamics are enough.
  5. A detailed look at climate sensitivity
    Eric, Knutti and Hegerl summarize the climate sensitivity by a variety of methods. The overwhelming consensus is 3C with a long tail upwards. Anything less than 2C is unrealistic. Please produce a link supporting your claim that 1C is a number that is capable of being considered. Here is the key graphic. Image and video hosting by TinyPic Please describe using the graphic how you conclude 1C is reasonable. The lowest high confidence intervals stop at 1.5C and most stop at 2C. There are long high tails. This graph has been posted many times to SKS since you started posting. Can this graph be added to the climate graphics page?
  6. Do we know when the Arctic will be sea ice-free?
    In that BBC video news pointed by shoyemore, from ~1:00 to 1:15, they used the PIOMAS ice volume animation by our own andylee just less than a week before! Congratulation to the team, for our science communication having such fast impact on mainstream media, and especially to Andy for this piece of animation well done!
  7. A vivid demonstration of knee-jerk science rejection
    I have read with interest the continuing discussion with Eric (skeptic) and his obsession with models. Forgive me, but I always thought that models are used to predict stuff. If the prediction eventuates, then we can have faith in the science and assumptions used in that model. By necessity, due to uncertainties in current knowledge and limitations in computing power, the models cannot predict reality entirely, but they are useful in projecting trends, and we need this to try to predict any consequences of continuing CO2 build up. Eric seems to have things precisely ass-backwards. What he is essentially saying is, forget all the overwhelming evidence we have now for AGW. Unless the models can accurately predict all this evidence (to his own arbitrary standards), we can't be sure that it is happening. Or did I miss something?
  8. A vivid demonstration of knee-jerk science rejection
    @49 Lambda 3.0 However thankless and tiring it may be, it is important to rebut the denialists. Any wrong or misleading arguments used by denialists should be rationally corralled, lest they infect the unwary "Cautious" ... and outright conversion of denialists to Warmism is not unheard of.
  9. Do we know when the Arctic will be sea ice-free?
    Professor Peter Wadhams of Cambridge seems to be the one responsible for the "2015" prediction. Here he talks to the BBC, and I gather he is making a documentary with them on the Petermann ice island. Should be interesting. "Arctic melt is like doubling CO2"
  10. A vivid demonstration of knee-jerk science rejection
    re: 44 chriskoz Thanks. This reminds me of a long discussion I had during a working lunch with folks at NCAR, after I'd done a lecture in mid-1990s: I'd asked them to assess the various impediments to progress. Someone categorized them as follows: 1) Data 2) Science 3) Compute power 1) DATA. the necessary data might not exist. Scientists might like satellite records going back 2000 years, including solar insolation and volcanoes. Such would be really useful in better calibrating climate sensitivity, which after all, is one of the reasons for doing paleoclimate reconstructions. Of course, and I forget who said this, but the idea was that people would love to have data from the future, but unfortunately it was not available. Even ignoring emissions choices, no one can possibly predict an exact path given ENSO transitions. Even if someone could, there are still volcanoes. 2) SCIENCE. In some cases, there weren't practical science models. Clouds were difficult. Inflection points / nonlinearities are tricky to model, etc. 3) COMPUTE POWER. And finally, some effects simply could not be seen without getting grid elements small enough or intervals short enough. Since I was helping sell supercomputers, I was always pleased to hear this. But as usual, for some kinds of problems, resolution might already be adequate, or could be known to become adequate, but the barrier might be in data or science. They were of course always making tradeoffs of resolution versus run-time, with bounds on CPU performance, memory footprint, disk storage, I/O bandwidth.
  11. A vivid demonstration of knee-jerk science rejection
    @47 mikeh1 said, "Any communication strategy needs to be directed at the bulk of the population who are still open to the science." Relevant to action in the States, the Leiserowitz et al paper, Global Warming's The Six Americas shows that the hard-core denial community stands at 10% of the US population. At least if you can put the deniers and fake skeptics in the "dismissive" category. Another 15% are in the "doubtful" category and are mostly influenced by the dismissive. In the segment that accepts the scientific consensus, we have 39% (13% alarmed + 26% concerned). In the middle are the cautious (29%) and the disengaged (6%). Since we observe denialism is resistant to reasoning and observations, shouldn't we be focusing efforts on educating the Cautious? While it is interesting to understand the psychology of denial, it seems that a lot of the effort that goes into direct rebuttal may be better focused on educating those Cautious Americans who haven't tipped into outright support of opposition of a national response to climate change. I'd like to see thoughts and research on how best to reach, teach, and motivate the Cautious segment to support reasonable action to mitigate and adapt. Also, don't these numbers show that the elected policy makers shouldn't have that much to fear from the denial community (25%) when there is so much support for the scientific consensus among the 39%? But then, there are the trillions of dollars in proven reserves of fossil fuels that must be written off at some point. I'd rather write off the profits than our descendants.
  12. A vivid demonstration of knee-jerk science rejection
    Andy@40 "because of the deeper failure of all of us to respond rationally to a novel, slow-motion, global, invisible threat. We have not evolved the instincts nor developed the social frameworks to address a problem of this nature adequately." I'm not entirely convinced. The threats posed by acid rain and the ozone hole were equally 'novel, slow-motion, global, invisible' threats to the populace at large, but governments listened to scientists and enacted sensible provisions to deal with those threats. I'm guilty of never having doubted climate science right from the beginning but mainly of presuming that the response would take the same course as it did for CFCs and acid rain. When we installed our solar hot water service in the 80s, I really thought that they would be the only kind of basic residential hot water services newly installed in Australia by say, 2000. When the first Rio conference came out with its vaguely worded objectives I was still certain that it was merely the first step in a diplomatic process to pin down the specifics - just like CFCs. I turned out to be wrong. But I'm pretty sure that that is because the diplomatic, political and business environment changed. I'm very glad that we identified the ozone hole problem when we did. If we were trying to deal with it now, I very much fear we wouldn't succeed.
  13. A vivid demonstration of knee-jerk science rejection
    Back to the topic. I am a regular at The Conversation. John's article attracted all the usual deniers who troll the climate science articles there plus a few new names including a fake "anthropologist" and a fake "climate scientist". Reading the comments, it is pretty clear that they are hardcore deniers and would not be persuaded if the Greenland and Antarctic ice sheets melted tomorrow. Any communication strategy needs to be directed at the bulk of the population who are still open to the science. To that end, I am bemused by sites like The Conversation which has a large readership and this charter http://theconversation.edu.au/our_charter but also allows the climate science denier trolls free rein. They have some great articles from actual climate scientists which are impossible to have a sensible discussion about because of the organised and intensive trolling. In my opinion that is insane. It is like going to a public meeting where a few loud and aggressive voices are allowed to shout from the back of the room to prevent any discussion - there is nothing democratic about it. I like the "put up or shut up" moderation policy which is generally implemented here because to quite frank, I am no longer interested in reading the same recycled denier arguments for the umpteenth time. And as a communication strategy, allowing deniers to post their anti-science rubbish on a university/science site sucks.
  14. A vivid demonstration of knee-jerk science rejection
    Sorry about the first paragraph, a little garbled. There is absolutely more uncertainty about potential positive feedbacks such as melting methane deposits. I am only claiming that the uncertainty about climate sensitivity calculated from paleo evidence is towards the low side of sensitivity.
  15. A vivid demonstration of knee-jerk science rejection
    I have hit one of the hazards of being off topic for which I apologize. My comment on uncertainty is narrow, only applying to the last paragraph in #31 by KR. There absolutely uncertainty in the realm of positive feedbacks, for example methane from permafrost, etc. Those are not what I was considering paleo evidence, namely the changes in conditions from glacial to present. I realize my narrower claim of uncertainty still needs support. Here's a post on that topic chriskoz, since we are trying to project for 100 years, we need to run for 100 simulated years and accuracy of the results does depend on the temporal granularity of the model. If the model cannot depict the evolution of convection then it can't determine the climate effects of convection. It must instead rely on parameterizations that can only be derived from the current (mostly inapplicable) climate. The faster sea ice melt should be expected following a positive AO winter (similar to 2007) and mostly represents a natural fluctuation. The models do poorly precisely for that reason.
  16. A detailed look at climate sensitivity
    Here's a paper Sea-salt aerosol response ... from the Cornell website. The paper uses a model to compare climate (precip, wind and salt aerosol loading between those four climate regimes. The precipitation shows a steady increase from glacial to preindustrial to present to future with doubled CO2. That represents a negative feedback as the increased latent heat transfer offsets some of the increased GHE. The wind shows a fairly drastic difference from glacial to the other three regimes indicating that measurements such as sensitivity of climate to a forcing change from the glacial to interglacial can't be applied to interglacial to future. Tom in #72 replies that even if we are in a "Goldilocks" climate state, BAU will lift temperatures by 2-3C. My answer is there are not sufficient changes in the climate regime (compared to LGM) to do that. There are large decreases in wind (and consequent dust and other aerosols) that will not be duplicated to any significant extent in the forthcoming change from current to doubled CO2. The precip increases will work against temperature increases. In fig 3b (post 72) the left two squares are red because the starting conditions (LGM) are too different from today's starting conditions and the sensitivity estimate cannot be applied. I am trying to show further that the sensitivity estimate is also an overestimate due to the greater magnitude of climate changes from LGM to present than present to doubled CO2. People may argue that the increased difference is accounted for simply by the increased GAT change, but that change was only 4-5C.
  17. Realistically What Might the Future Climate Look Like?
    I havent tried to do this calculation for rest of world, but for NZ (which is heavily agriculture based), it was pretty easy to supply farm fuel needs with biofuel, particularly if woody biofuels or algal fuel that use non-arable land. Could even do transport diesel. So, I dont think we would starve without fossil fuels. Doing biofuel for all the other things that we use fuel for (especially private vehicles) is another story altogether.
  18. A vivid demonstration of knee-jerk science rejection
    JohnMashey@43, Well said. I especially like the distinction beetween weather and climate as "Initial Value Problem" vs. "Boundary Value Problem". Eric (skeptic) clearly ignores this distinction. The evidence supporting my claim here, is that Eric expressed so much concern about the resolution and accuracy of local processes in climate models, i.e. he's concerned that climate models are "unable to model 100 years at 10 minute and 1 square mile resolution to capture convective precipitation processes". Apart from obvious fact that the accuracy of results does not depend on how long the models runs; we all know, that boundary value problem is not resolved by increasing model's accuracy. That's nonsense, a common fallacy of those "researchers" who "look at the tree & don't see the forest". Eric is also concerned about the cloud formation dynamics: very localised processes. They have nothing to do with the actual science of water vapour feedback which is large scale (global) process. To fine tune the boundary value problem models, such as AOGCM, a well mixed system, you must seek to better understand global processes. A good way to do fine-tune a complex, turbulent system such as climate, is by careful observation and correction of parameters. E.g. latest observations in the arctic strongly suggests that our models underestimate the current AGW. The much faster than expected sea ice melt means the arctic ice albedo positive feedback (eqiv. to 20y of emisions at current levels see here) be indicative of higher than expected CO2 sensitivity, or faster than expected eqilibrium earth system response. Eric simply ignores that observation and blatently states that "climate sensitivity is low" against it. That's a classic cherry-picking. There might be other aspects of the denialist attitude represented by Eric, people like Steve Lewandowski might be able to point. I just pointed those aspects that I'm sure about.
  19. AGU Fall Meeting sessions on social media, misinformation and uncertainty
    GeoffChambers @130, I assessed the distribution of conspiracy theory responses for acceptors, undecided, and rejectors of AGW. Only for recectors is their any hint of a bimodal distribution; and that hint consists solely of the two dubious proxies. Therefore the suggestion that the distribution is bi-modal is ad hoc. Likewise, based on the limited literature I have read on the topic, there is no record of anyone strongly believing more than a few conspiracy theories simultaneously. Based on that, the supposition that such people do in fact exist and came out of the wood work solely for the benefit of this survey is also ad hoc. We are faced with two theories about the two suspect responses. The first is that they are attempts to game the survey. The theory that people attempted to game the survey is already confirmed , with at least 5% of responses known to have been attempts to game the survey. That makes the first theory both simple, and a theory with support behind it. The alternative theory is complex because it requires the existence of (so far, unsighted elsewhere) universal conspiracy theorists; and also requires a bimodal distribution, but only among rejectors of AGW. Given the choice between a simple theory with supporting evidence, and a complex theory requiring ad hoc hypotheses, I will always choose the former. Never-the-less, I am not saying Lewandowsky should exclude those two responses from the survey. Rather, I am saying he should make people aware of the reasonable doubt, and ideally show that their inclusion makes no difference to the result. (I believe that is indeed what he is claiming, although I have my doubts.)
  20. A vivid demonstration of knee-jerk science rejection
    Even if using the same code, weather and climate models are *different*, in some sense analogous to the difference between old-style protein-folding and climate models. Steve Easterbrook gives a good explanation of the difference between models for weather (Initial Value Problem) and climate (Boundary Value Problem). They are different, and knowing something about weather models does not automagically generalize to climate models. See RC's FAQ #1 and FAQ #2.
  21. A vivid demonstration of knee-jerk science rejection
    Eric (skeptic) @ 32, Sphaerica @ 36, KR @ 39 Yes. Isn't it odd that Eric is so certain about which portion of the uncertainty range contains the correct answer. Add me to the list of people that would love to hear Eric's explanation, justification, and support for his claim that the range of uncertainty is actually much, much smaller than that seen in the scientific literature. ...because that is basically what Eric has claimed: that the scientifically-indicated range of uncertainty is wrong - that he knows better and that he knows the correct answer is down at one end.
  22. A vivid demonstration of knee-jerk science rejection
    Andy S Guilty as charged and +1.
  23. A vivid demonstration of knee-jerk science rejection
    Great comment, Kevin@37. I think that we need to be careful with all of these psychological explanations of why climate change "skeptics" think and reason the way they do. Firstly, as you said, it's all too easy to misuse these studies to categorize "skeptics" as somehow deficient in reasoning, which can be, at best, patronizing and at worst, dehumanizing. Secondly, it's all too easy to forget that our thinking processes, which are often driven by emotion first and reason second, are common characteristics of all of us, not just of people we disagree with. It's great fun to see "skeptic" commentators say things in responses to Stephan Lewandowsky's and John Cook's articles that seem to make the original authors' case for them. We must remember, though, that the problem with our, so far, inadequate response to climate change is not because a handful of internet pundits behave irrationally, but rather because of the deeper failure of all of us to respond rationally to a novel, slow-motion, global, invisible threat. We have not evolved the instincts nor developed the social frameworks to address a problem of this nature adequately.
  24. A vivid demonstration of knee-jerk science rejection
    Eric (skeptic) - "...all the uncertainty points to lower sensitivity." And now you have explicitly stated a fallacious argument - that all the uncertainty favors your point of view. This is completely contrary to the evidence, wherein the bounds on low sensitivity are quite strong, and the bounds on a much higher sensitivity are in fact less constrictive. The uncertainty actually favors a higher sensitivity, not a lower one. As with Sphaerica - I'm going to have take your position as nonsense (a mix of cherry-picking and confirmation bias) unless you can provide some citations, some evidence, supporting your point of view.
  25. A vivid demonstration of knee-jerk science rejection
    Interesting comment from Kevin, thought-provoking. Funny thing is (and it perhaps illustrates Kevin's thoughts in terms of mirroring) last night I paid a visit to Lewandowsky's blog and the comment stream immediately led me to think of "mobbing." Later on I realized that by sheer numbers there was not much of a mob there, really, just a few shouters.
  26. A vivid demonstration of knee-jerk science rejection
    OK, I'll have a go at the sociology. Huge D-K caveats over all of this. My principle source is Girard, although there probably bits of Derrida and others mixed in here too. When communities face problems they tend to find outlets for that pressure, in the form of a response which is some modified form of violence. Often this involves the creation of a victim or class of victims (the scapegoat) on which the problems can be blamed. To avoid compromising our own humanity, dehumanisation of the victims is usually a part of the process. The victimisation process release the tension and builds common cause within the community. We all do this, it's our anthropology. Lots of illustrations: Emmanuel Goldstein in 1984, the skeptic community's demonisation of Micheal Mann, immigrants. Is US politics more polarised this year? Related to recession? The conspiracy paper is not about climate. So of little interest to many of us here. However the response is interesting to me, because of the social anthropology. The skeptic community reacted very strongly against it. Elsewhere in the consensus community the paper also got quite a lot of play (e.g. it made the Guardian). Once it attracted criticism, many leapt to its defence (again fewer here), despite it's irrelevance to climate science. What is going on? The paper is very easy to play as a tool for dehumanising skeptics: 'They can't help being skeptics, it is because they are psychologically predisposed to conspiracy theories'. Put like that you can see why it would go down badly. Worse, the more insecure members of our community can use it to reason 'we are rational thinking individuals, they are controlled by their psychology'. That the 'controlled by their psychology' argument cuts both ways is no doubt obvious to a psychologist like Lewandowsky, but it is a common mistake. As a result, I think the paper unintentionally played to and was exploited by the less science-focussed elements of the consensus community and it's followers, and was used to dehumanise the image of the skeptic. The title of the paper certainly didn't help in preventing it from being abused in this way. That's my impression as to what is going on. Biggest caveats: None of my observations are objective and they are all suspect. The patchiness of my social anthropology no doubt biases me to interpret things in the light of the bits I know. On a personal note, the creation and dehumanisation of victims is part of our anthropology, and certainly it comes very naturally to me, yet at the same time I find it abhorrent. I can't stop others doing it to me, but neither can I participate in a community in which doing it to others is normative. Fortunately, SkS has on the whole managed to avoid this.
  27. AGU Fall Meeting sessions on social media, misinformation and uncertainty
    Because Lewandowsky said it was... And Lewandowsky was indeed correct. ...and when McIntyre did find it... Weeks after it was sent. Minimum lesson learned: Read your own email.
  28. AGU Fall Meeting sessions on social media, misinformation and uncertainty
    133, Geoff,
    Because Lewandowsky said it was...
    So what? He said he did, they claim he didn't... oh, wait, McIntyre found it but ignored it. Again, so what? How did this in any way invalidate the study? Or do you just feel for McIntyre's poor, trod on sense of importance?
    Of course it is.
    Oh, Jeeze. So you think there was a warmist conspiracy to pretend to be skeptics, just to get them to look bad? Holy moly...
  29. A vivid demonstration of knee-jerk science rejection
    32, Eric,
    ...all the uncertainty points to lower sensitivity.
    This statement is direct contradiction of the science and utterly without support. Please supply a single, published citation that supports this presumption of yours. Looking at the range 1C to 5C and picking 1C because you personally think, in your own thought-experiments, that the "more positive feedback there was from lower dust levels, the lower the sensitivity to rising CO2" is true... ... is just plain insanity. How can you possibly separate yourself from the deniers? You began this thread by claiming "a large majority of skeptics agree with the 97% of climate scientists on AGW." I call "B.S.". You yourself are in complete denial. How can you speak for this large majority (that I have never seen)?
  30. A vivid demonstration of knee-jerk science rejection
    Eric (skeptic) - Regarding ice-age dusts, it's not clear whether they provided negative or positive forcings, so again you are assuming ("positive feedback") a one-sided uncertainty. And you're back on the models, which (IMO) represents a cherry-picking of the evidence.
  31. AGU Fall Meeting sessions on social media, misinformation and uncertainty
    Sphaerica #132
    Why do the conspiracy theorists among us actually care that this survey was or was not offered on self-proclaimed-skeptic blogs?
    Because Lewandowsky said it was, and all the major sceptic blogs denied having found it, and when McIntyre did find it, it came from a different person, with a different introduction, attached to a different questionnaire, one week after it had already been publicised and widely discussed on anti-sceptic blogs. All points which need explaining, and which Lewandowsky refuses to address.
    Is the fear that skeptics who visit other blogs aren't representative of "real" skeptics, and so the study was improperly skewed towards a not-acceptable-as-a-real-skeptic population?
    Of course it is. (-Snip-)
    Moderator Response: [DB] Ideology snipped.
  32. A vivid demonstration of knee-jerk science rejection
    Ari, if you go back a few decades it's easy to see that Lindzen actually did earn his AGU Fellow badge. That was before he converted his reputation and scientific capital into a simple machine for applying political force. His AGU Fellow status is key part of the little mechanism, might be likened to a fulcrum, with the MIT gig being the long end of a lever. Reduce, reuse, recycle, one might say, with emphasis on "reduce." Using MIT and AGU in this way necessarily reduces them while lifting Lindzen's cause. Being associated w/dousing is bad for efficient functioning of Lindzen's device, akin to the same problem AGU and MIT face.
  33. A vivid demonstration of knee-jerk science rejection
    I don't think Lindzen's early stuff (and this one too) had any more legs than his current nonsense.
  34. A vivid demonstration of knee-jerk science rejection
    KR, you'll have to be more specific in those threads. Sphaerica, we are at the low end of paleo only because, contrary to KR, all the uncertainty points to lower sensitivity. To give a very simple example, there are layers of dust in ice cores during ice ages. The more positive feedback there was from lower dust levels, the lower the sensitivity to rising CO2. A model incorporating dust is the only way to find out. That is why my focus is on the models.
  35. Record Arctic Sea Ice Melt to Levels Unseen in Millennia
    Sphaeric: energy "looks" cheap The crux of the problem, and we don't respect things that are "cheap." Treat energy as we would a rope suspending us over a bottomless gulf and we'll do better. If the rope we're hanging on is showing obvious signs of fraying, arrange a better rope as fast as possible. Remember that more than one rope is better.
  36. A vivid demonstration of knee-jerk science rejection
    Eric (skeptic) - I went back and re-read the thread you referred to; in that thread you repeatedly dismissed observations (including claims that the observations don't make sense without models!), focused entirely on models, and claimed uncertainty regarding those. Followed by (in several threads) suggestions that we wait a few decades until our models improve - while not giving a solid criteria for such improvement, which leaves Moving the goalposts, or Argument by demanding impossible perfection wide open. Sphaerica is (IMO) entirely correct in his assessment that you are overly focused on models, which is itself a form of cherry-picking, an argument from fallacy. You seem to be assuming that if you can, or have, disproven something about one line of evidence, that the entire house of cards falls down - and to support that argument, you refer everything to your focus, 'models'. You are, as John Cook discussed, not looking at the full body of evidence. Now, as to uncertainties regarding dust, jet streams, etc. - you have implied (although not explicitly stated) a different fallacious argument: that such uncertainties go only in one direction. Any uncertainties regarding glacial or interglacial era feedbacks WRT current conditions could just as well mean that we will see worse feedbacks now. There's no reassurance in that kind of uncertainty.
  37. Why Arctic sea ice shouldn't leave anyone cold
    The thermo/haline stratification in the Arctic ocean is one of many elephants in the room. There is enough heat in the deep, salty, slightly warmer (from 1 to 2.5 degrees) water that fills the deep basin of the Arctic ocean to melt all the ice a number of times over. One meter of water which is 1 degree above the freezing point of the ice that lies on top of it contains enough heat to melt 12.5mm of ice (latent heat of ice is 80cal per gram). Much of the Arctic ocean outside of the continental shelves is a thousand meters deep. As the Arctic becomes more open water earlier and earlier there is more energy to power storms such as the one of Aug6. These storms cause upwhelling along the shore and pull this deep "warm" water to the surface. Internal waves which the storm causes break as the reach shallow water and further mix the layers. After each summer storm of the magnitude of the one this year (or greater) will see a dive in the ice extent graph. It is just possible that we could be ice free next year or at most in a couple of years. http://mtkass.blogspot.com/2008/07/arctic-melting-no-problem.html
  38. Record Arctic Sea Ice Melt to Levels Unseen in Millennia
    For all deniers, if: 1) The droughts, fires, heat-waves, increase in storms and other impacts that we've seen in the past decade are the effects of the warming we've seen to date... 2) The melting of the Arctic ice is an effect of the warming we've seen to date... 3) The melting of the Arctic ice further exacerbates that warming to a marked degree... 4) The inertia of the system means that we are still accumulating further warming on top of what we see now, even if we cut all emissions today... 5) More warming will mean that the droughts, fires, heat waves, storms and other impacts become that much worse... 6) These negative factors must continue for at least hundreds of years, maybe more... 7) The economic impacts of those effects of warming for hundreds of years will be huge... ... All because we couldn't/wouldn't invest a little bit of effort into:
    a) A less careless attitude towards energy and resource waste b) Renewable energy sources c) Less profits for fossil-fuel companies d) More jobs through efforts to upgrade and improve our energy and transportation infrastructures e) Lower prices and more efficiency through more local product sources, rather than shipping everything back and forth around the globe because energy "looks" cheap
  39. A vivid demonstration of knee-jerk science rejection
    29, Eric, So 1C to 5C for you translates into "let's assume 1C"? Also, your CO2 comment is nonsensical. Normally, CO2 is a feedback, but in our case it is a driver. Yes, every system is different so the feedbacks from one case to another vary, but your silent hope that the same feedbacks or degree of feedbacks suddenly won't apply, just in this one special case smacks of desperate denial to me. Your further statement -- that you need models to estimate the actual feedbacks -- goes back to your own particular tic. You cannot get past the models as your single-minded focus. Everything comes back to the models. And this is your own personal non-sequitur. 1) You don't trust the models. 2) Therefore global warming is not happening.
  40. A vivid demonstration of knee-jerk science rejection
    The paleo evidence gives a wide range, about 1C to 5C, for sensitivity due to uncertainties in feedbacks. The only way to narrow the range is with a model. KR points out here that "paleo evidence is a very strong indicator of total feedback". But CO2 is not the only feedback and the feedbacks that are not applicable to today's climate (dust, jet stream shifts, etc) must be subtracted out using a model.
  41. Record Arctic Sea Ice Melt to Levels Unseen in Millennia
    To add to Sphaerica's last point, orbital forcing--the primary forcing behind ice ages--is trying to cool us right now. Yet we warm. Tzedakis et al. (2012) tells us that we need less than 280ppm CO2 for ice age glacial inception. We're at 395ppm right now and growing rapidly. CO2 is going to take a long while to drop, even if we went to zero emissions today. We're not going to go to even zero trend for at least decades.
  42. Record Arctic Sea Ice Melt to Levels Unseen in Millennia
    Jack, looking critically at Arctic maximum requires one first and foremost to take into account land constraints. Max area is constrained by land. If there were no land in the northern hemisphere, the winter max area trend would be much more useful than it actually is. It is a downward trend, but not quite as severe as summer minimum trend, and the trend starts to increase later in the winter series compared to the summer. The area that melts each melt season is also increasing. If minimum were today, 11.35 million km2 would have melted, an instrumental period record. Not surprising, though, since the ice is thinning. While 2012 started out anomalously high in area (against the trend), the drop was staggering in intensity when it came. There were 22 60-day periods where the average daily loss was over 100k km2. There was one such period in the entire instrumental record before this year. Will October be an equally sharp beginning to the race to the maximum? Or will the warmth linger and force the growth spurt to begin in earnest later? Volume trend is down on every day of the year when using the full record as a basis. I get something like 2070 for winter max ice free when I extrapolate a ten year linear to zero intercept. That's unlikely, of course. Funny thing is, I can't tell you why. I suspect that decrease will slow as area max gets closer to the 80 degree line, but if ice is still mobile, then there's no reason to think it might not be susceptible to flushing and mixing. This year's anomaly was, for my money, greatly enhanced by high-temp river drainage. That drainage was high temp thanks to the heat concentrated over parts of Siberia and North America (and the snow cover anomaly). And that, of course, can be tied to polar amplification related changes to the big circulation cells. 2013 is a crucial year. If we get a repeat of 2012, then 2012 will probably be considered the second barrel of the 2007/2012 tipping points. My penny and a half.
  43. Record Arctic Sea Ice Melt to Levels Unseen in Millennia
    Jack W, Your point is certainly worth addressing, and from several angles. (1) First, the facts about ice "recovering" in the winter... yes, it does, and you correctly note that it does not have the same thickness. What matters here is two things. First, most of the Arctic is in 24-hour darkness for about 1/4 of the year. [See this fun toy here and this even better one here.] This means that it is going to get very, very cold up there when the sun is down, so it is no surprise that the ice is recovering (for now). But... despite the mere loss of something that has existed for maybe up to 100,000 to 800,000 years, the loss of summer ice puts in motion some dangerous feedbacks. It doesn't matter much if the Arctic is ice covered in the winter, but if it is open water during the summer, it will absorb rather than reflect the sun's rays. That absorption results in a major change in the energy balance. One scientist recently estimated this as equivalent to adding another 20 years worth of CO2 emissions to the atmosphere. And that's not the only feedback. Scientists grow ever more worried that we are going to release vast quantities of methane tied up both in the permafrost and in the Arctic seabed. Combined, these factors will multiply the effect of man's carbon emissions. We've known that this would happen in general (search for "climate sensitivity" and "positive feedbacks"), but not necessarily this quickly. That's frightening. (2) Beyond this, the fact that the Arctic is returning to an ice-covered state in winter is not guaranteed to continue. Studies have been conducted that the Arctic only has two stable states, ice-covered or ice-free. What we are seeing now may be a short-lived interim period while the system toggles from one state to another, but it may well be that when the globe warms enough and enough ice vanishes that the Arctic does not grow sizable amounts of ice even in months of 24-hour darkness. (3) As far as being beyond the point of no return, yes, that's what has everyone scared... that we've already passed a point to stop this, and the subsequent positive feedbacks will kick in, making things even worse. (4) As far as not being sure what portion to attribute to human endeavors. First look at 1, 2, and 3 and tell me that you're willing to take that risk. Second, consider that what we're seeing in the Arctic hasn't happened to this extent since 6,000 years ago, at the peak of the Holocene Thermal Maximum (i.e. the warmest period of our interglacial -- for thousands of years we've been in the slow decent into the next glacial, and this reversal we see now is unheard of in the 800,000 year ice-age record). Given that all other factors -- a quiet sun, for example -- leave nothing except anthropogenic influences to be driving temperatures higher than they've been in 800,00 years, and given that a completely ice-free Arctic, if we reach that state (which as you've said now seems inevitable), a state that has not existed on this planet for hundreds of thousands of years and maybe not since the start of this ice age (period of glacial/interglacial transitions) 2.6 million years ago... do you really question the anthropogenic influence here? Which of nature's fairies is raising temperatures and melting the Arctic ice in a way this planet hasn't seen in hundreds of thousands and maybe millions of years?
  44. Record Arctic Sea Ice Melt to Levels Unseen in Millennia
    Jack W: Tamino has a graph derived from NSIDC data and a link to (and information extraced from) a paper, Kinnard et al 2008, showing maximum extents and minimum extents. (Note that the NSIDC info requires log-in to view directly and the Kinnard et al paper is behind a paywall.) It appears that maximum extent has declined slightly (insofar as a 1 million km^2 decline is slight). I am not certain your criticism of the graphs is on point. An annual January-December plot of sea ice extent has no 'zero' in the time axis; nor does a sea ice plot since the start of direct satellite measurement (in 1979) or century-long reconstructions (the Kinnard paper). There is also, as far as I can see, nothing misleading about omitting some lower values of sea ice extent that the sea ice hasn't reached, until it becomes necessary (which, to be fair, may be sooner than we would all like).
  45. Record Arctic Sea Ice Melt to Levels Unseen in Millennia
    Jack, the surface of the Arctic ocean will freeze in winter to fill the space available to the ocean itself, regardless of the thickness of the ice. The -maximum- extent of the ice is set by the general geographic arrangement of the ocean and land, so failing us plunging into a new ice age or the planet becoming much warmer than any projections (as far as I know of, anyway) that maximum isn't going to change a lot. As to the scale of the graph, think about a clinician plotting a patient's temperature. Scaling the graph of the temperature of a human body to zero would cause the clinician to miss changes in the patient's temperature indicating drastic health problems. It's kind of the same deal here; the ice extent in summer does not have to drop to zero to tell us we can expect systemic changes in weather and climate in the NH.
  46. AGU Fall Meeting sessions on social media, misinformation and uncertainty
    I'm a little confused here. Why do the conspiracy theorists among us actually care that this survey was or was not offered on self-proclaimed-skeptic blogs? The results were sorted and analyzed based on the answers, not the source. Is the fear that skeptics who visit other blogs aren't representative of "real" skeptics, and so the study was improperly skewed towards a not-acceptable-as-a-real-skeptic population? Or is the problem that someone like McIntyre didn't get to manipulate the outcome by coaching his visitors through the answers? I rather suspect that if the survey had been offered at "real" self-proclaimed-skeptic blogs, the conspiracy-signal would have been magnified. It could only have helped to strengthen the results -- unless the inane, bizarre and quite indefensible comments that I see on self-proclaimed-skeptic blogs are somehow not representative of the nutters that frequent/post on them, or they would have suddenly put on their sanity-caps while filling out the survey, then taken them off in order to post more stupid comments on their favorite self-proclaimed-skeptic blog. It is what it is. Get over it.
  47. A vivid demonstration of knee-jerk science rejection
    22, Eric, I did not say that paleo evidence supports the models, I said that it supports the same estimates of climate sensitivity given by the models. Forget the models. And so you also missed my point in #4. The fact that you missed the point clearly demonstrates it! You are in the mode that everything hinges on the climate models, you don't trust them, and you cannot in any way separate from those two facts, so all of your thought processes stop there. I would strongly recommend that you ignore the models completely and begin to study and learn the other aspects of the science. You are trapped in a set of "I don't trust models" blinders. You don't argue against the rest of the science. You simply ignore it (unless it has something to do with the models).
  48. Climate Deniers Are Giving Us Skeptics a Bad Name - Fred Singer
    Bernard@67: Whew!!! I thought this was about *Glenn* Beck, and my head was about to explode...;) Thanks for helping me clear ~that~ particular nasty bit of imagery out of my head!
  49. Record Arctic Sea Ice Melt to Levels Unseen in Millennia
    It's all very intriguing, but I have one question, I'd like to see answered that seems to be whitewashed over. I'd like to pre-qualify that question with the statement, that I'm not disputing Global Warming. Obviously we have it, but what portion to attribute human endeavors I'm not willing to put a figure to. Now my question is, we see how much ice coverage we are getting in the summer, but from all I can find it appears we still have about the same average coverage "area" in the winter. Now obviously the coverage is getting thinner, but we are still getting around the same amount of ice area in the winter. Correct me if I'm wrong and point me to sources disputing that. Now, of course, I'd also like to point out, based on the graphics that the plots are a bit self-serving. I'd like to see graphs with zero points on both axes, and some of the lines are plotted to look more/less severe than they are in reality. Lastly, I'd like to point out, based on the current slope, we might now be in an asymptotic curve (whether geometric or exponential is not clear from the distorted graphs) and there really isn't anything we can do to stop the ever impending and accelerating approach to "Arctic Ice Free Summers". Since it looks like we are not even coming close to icefree winters. Anyway, I've long suspected we were past the point of no return on this item, based on my own readings and math knowledge.
  50. AGU Fall Meeting sessions on social media, misinformation and uncertainty
    Foxgoose@128 ...because anyone with any experience in such surveys knows that you never get 100% response - there will always be someone that won't reply. You take what responses you get, and you move on. McIntyre is no different from anyone else that was contacted about the survey, and I would be surprised if he were to get any different treatment from anyone else - and to give him special treatment and make extra effort to get him to participate (beyond what was established in the protocols for the study) would likely give reason to wonder about the results. You seem to think that McIntyre actually matters as an individual - he's just another one of a group of people invited to participate, and in the context of the study he doesn't mean anything more than "blogger X". He make think he's more important than others, and you may think he's more important than others, but for now all you've got is a tempest in a teapot, and you're still circling the drain of "conspiracy theory".

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