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Comments 74251 to 74300:

  1. Lessons from Past Climate Predictions: IPCC AR4
    I was wondering a bit about this trend stuff myself, so I set up a bit of code that tries various different values for start year and trend time and calculates a linear regression slope in the gistemp or any other temperature data set. My resulting plot is displayed (hopefully) below: Although it's not a statistical test, it can inform one's intuition for how sensitive to trend the pick of a start date is. Sure enough, it's trivial to cherry pick a recent ten-year trend to give values as low as between -0.05 and zero or as high as 0.3 degrees per decade for ten year trends from 1998 and 2001. The 15 year trends, however, are much pretty stable in IPCC compatible ranges. I like to call this a "cherry checking chart."
  2. SkS Responses to Pielke Sr. Questions
    @Grypo, Albatross. I should have gone on to say that I think if the aim is to attract sceptic scientists onto this site -- which would be really good -- you need to find ways whereby they don't feel quite so threatened. Threatened people lash out, and when they're clever they can do a lot of damage. The best way is always to remain calm yet very firm and confident. Relax them and they will hang themselves -- otherwise they'll leave long before you get the chance to be executioner. I really wanted to 'hear' Dr Pielke answer your questions. As it is I feel like I've had the main course put down in front of me and then snatched away.
  3. SkS Responses to Pielke Sr. Questions
    I think something like this has already been suggested above, but I'd have thought the best way to manage a discussion like this in the future would be to have two parallel threads. One which is open for anyone to comment on, so those who really know what they are talking about can post sensible comments and relevant links and the rest of us can throw all the peanuts we like. The other, where the real discussion would take place, would be closed to comments, except from the key players, but with the best and most constructive comments from the open thread being transferred into it as moderators see fit.
  4. SkS Responses to Pielke Sr. Questions
    @Grypo, Albatross. Yes, fair points. I used the word 'attacked' as shorthand for a word I couldn't think of. It's an emotive word and I should be able to think of a simpler and shorter one -- but, with that proviso, you get my point.
  5. SkS Responses to Pielke Sr. Questions
    @Dikran We'll have to just disagree about Prof Jones' answer, which we've discussed before. Really, I do sympathise with your point of view but -- and I'm laying myself open to charges of elitism here -- I think you over-estimate the lay person's ability to see through the games, particularly the lay person who comes to the answer with a 'denial mindset'. I find myself being led off-topic here so that's all I'm going to say.
  6. SkS Responses to Pielke Sr. Questions
    John Russell @161, "Having a group of people on one side who are generally autonomous, up against a single person -- whatever the merits of the respective arguments -- seems to any onlooker terribly like a pack of wolves attacking a bear." Thanks for your thoughts on this, I largely agree with you. But I think that one point needs clarification. It should be noted that, for the most part, only one person (me) had been actively "debating" with Dr. Pielke before he decided to get in a huff and leave. So there was not really a "pack mentality" at that point, and think that would be a very poor reason for anyone to provide for him electing to leave. He could have asked for a break, or could requested for the format to change, he did neither. Re your post @168, yes it was a technical discussion at times, but instead of using it as an opportunity to inform some readers, Dr. Pielke chose to berate/insult both the moderator asking him to elaborate and SkS as a whole.
  7. SkS Responses to Pielke Sr. Questions
    @ John Russell I think we can use a phrase like, 'vehemently disagreed with' instead of 'attacked', but also recognize that the numbers were not in Pielke's favor, giving the 'gang up' impression that I'm sure some people came away with. But let's also recognize the flip-side of that. The person that Dr. Pielke complained about is another PhD level colleague in Pielke's field and probably the most knowledgeable person to counter argue on those specific points in this thread. Another example is Dikran whose very legitimate questions about a paper that Pielke himself cites as important work (in Pielke's own peer-reviewed paper, no-less!) went unanswered and Dikran was instead told to email the author. These aren't voices we really want to censor. The forum in which we are operating unfortunately lends itself to poor endings to these exercises. As well as giving critics lots of fodder to use.
  8. SkS Responses to Pielke Sr. Questions
    @Former Skeptic I'm sure you will agree that it's very different when the person who is being 'attacked'-- for want of a better word -- (Pielke on this site, Schmidt on RC) is also the moderator (forgive me if I'm wrong, but I'm assuming Gavin was both the poster and the moderator on the example you provide). That creates a structure -- partly visual -- that makes it clear and logical. There is also the point that the RC post was not a series of questions, which also created a mish-mash on this thread as the commenters went for different arguments. As I said, for the lay person it was difficult to follow. But I agree that Gavin did a good job.
  9. Dikran Marsupial at 04:31 AM on 23 September 2011
    SkS Responses to Pielke Sr. Questions
    Former Skeptic@165 I just want to second what you wrote regarding Gavin Schmidt, an "exemplary job" is a very apt summary, it is hard to see how he could have done better. John Russell@166 I would hope that the lay-person can detect the rhetoric and evasion and not be impressed with it. My grasp of poltics is pretty weak, but I think I can still detect evasion in politicians and be unimpressed by it (and indeed when media types are just trying to trip them up rather than dealing with the substantive issues, I'm not impressed by that either). Scientists should always be willing to give a direct answer to a difficult question, c.f. Prof. Jones' absolutely straight answer to the question about the statistical significance of temperature trends. He did explain why the non-significance didn't mean much, but he didn't shrink from explicitly stating that the trend in question was not significant. I find it much easier to trust those willing to give direct answers to direct questions, especially difficult questions. Trust is irrelevant in science, but it is highly relevant to how the general public ought to form an opinion about the science.
  10. SkS Responses to Pielke Sr. Questions
    @Dikran. Actually, I agree with you. I was not proposing a debate (see my previous comment at #161). I also think John's moderation was fine -- but he had a thankless task and nothing he could have done would have created structure to the exchange. Reading the thread is just hard work. Fine for those with insight and the motivation to mine the content, but off-putting for the lay person -- which after all is the target audience this site sets out to reach.
  11. SkS Responses to Pielke Sr. Questions
    I followed this discussion with some interest, and expected that Dr. Pielke would abruptly leave and go back to his weblog to (for want of a better word) sulk. It's no surprise, given his track record at other climate science blogs (here and here and here) when his contrary opinions are challenged by the massive weight of prevailing evidence. It's tiresome to deal with Dr. Pielke, especially when he demands civility and respect but his online behavior can be argued to be opposite of such genteel notions. This (and previous threads) was seen with his general evasiveness, his misrepresentation of Albatross, and his surly response over at his blog. Jorg Zimmerman has an apt description of such concern troll-ish behavior that should be read by all here. Lastly, I would like to thank the moderators here for their efforts in trying to host a discussion with Dr. Pielke. John - IMO you did a good job in keeping things civilized, and you shouldn't be sent down to AAA for it. :) PS: John Russell. Good point about the pack of wolves vs. a bear analogy. However, in the immediate fallout the CRU hack, Gavin Schmidt did a exemplary job dealing with accusations flung at climate scientists by commentators over at RC over several (very) long threads. The contrast between how patiently Gavin responded to the ignorant punters, vs. how Dr. Pielke left in a huff when (IMO) politely challenged is very telling.
  12. Dikran Marsupial at 04:09 AM on 23 September 2011
    Lessons from Past Climate Predictions: IPCC AR4
    Robert Murphy wrote: "Our first intuitions can lead us astray." indeed, which is why we have statistical tests, which give us an indication as to whether out intuiutions have a solid evidential basis. Although frequentist hypothesis testing as it is actually used in science is arguably not fit for purpose!
  13. Lessons from Past Climate Predictions: IPCC AR4
    "I guess it depends on your start and end points." Of course; we're dealing with very short time scales. One year's temperature can make a huge difference with the trends when you are only looking at 10 years of data. That is why scientists look at longer timeframes. Linear trends for short timescales can be very deceptive; one would think that adding the ten years from 2000 to 2010 would lead to a smaller long term linear trend for 1990 to 2010 than for 1990 to 2000. It doesn't (for GISS anyway); the trend actually goes up. This despite the fact that the trend from 1990-2000(about .17*C/decade) is bigger than that from 2000-2010 (about .13*C/decade). Our first intuitions can lead us astray.
  14. Dikran Marsupial at 04:02 AM on 23 September 2011
    SkS Responses to Pielke Sr. Questions
    John Russell In my view a "debate" is exaclty what we need to avoid, what we need is a scientific discussion, and science has found over the years that this is best conducted in written rather than spoken terms (which is why we have journals). "debates" lend themselves all to easily to rhetoric and sophistry and favour the quick witted rather than the correct. Written form also discourages evasion as the original question is still there on the page, so any evasion is obvious. One advantage of a written format is that hecklers are not a problem, you can just ignore them and engage with those who are actually making a substantive contribution. You can't be shouted down or interupted in writing! Sadly there is no format of discussion that is completely robust to rhetorical devices of various sorts. The best thing to do is simply to note the use of the rhetorical device and carry on (this is not IMHO heckling). BTW I think the moderation on this thread (by John) has been just fine. It is often difficult to strike a balance between allowing comment on the style of the discussion (which is appropriate) without comments being inflamatory or unreasonably hostile. If someone is being evasive in a scientific discussion it is perfectly legitimate to point it out.
  15. SkS Responses to Pielke Sr. Questions
    @NewYorkJ: I think the problem is that a 'debate' is not really possible when carried out in written form like this. I felt for John Hatz. Being a moderator is not like being a chairman and it's not for nothing that a debate has a structure where one side speaks and then the other answers -- which is impossible in an open forum. The end result is difficult to follow, pulling in all directions. And then there are the hecklers who, due to the format, have as much prominence as the 'serious' questioners. Agreed, my suggestion is not as good as a well-structured open 'debate' but there is no way this would end up well-structured, is there? -- except by fluky accident.
  16. SkS Responses to Pielke Sr. Questions
    John Russell (#161), You make a valid point, but your recommendation sort of defeats the purpose of having an open discussion. I think others beyond the SkS authors have made valuable insights and posed unique questions here that might get lost with such an approach. Another approach would be for Dr. Pielke to open up comments on his blog. He has indicated that he doesn't do so because some comments are hostile, which I don't find convincing (hostile comments can be moderated out). From his blog (and from his interactions here) his chosen approach comes across as very dictorial. As far as hostility goes, no need to look further than his colleague Anthony Watts, who is trying hard today to denigrate this site and frame Dr. Pielke's interactions here. But now we're back to One-Sided Skepticism. I admire the moderators seeking to improve their approaches here in establishing dialogue and improving communication. I only wish those actions were reciprocal.
    Moderator Response: [John Hartz] Thanks for the positive feedback.
  17. 500 scientists refute the consensus
    Consider the rhetoric, bibasir: "More than 1000 dissenting scientists (updates previous 700 scientist report) from around the globe have now challenged man-made global warming claims made by the United Nations Intergovernmental Panel on Climate Change (IPCC) and former Vice President Al Gore." Why the initial use of "dissenting" when the substance of the sentence is to establish dissent? Upon what is this dissent focused? Note that Watts probably includes Pielke in this list, but Pielke accepts AGW; he just differs from other scientists on the contribution of various components. How many other of the "dissenting scientists" are in the same position? How many reject the idea that atmospheric CO2 absorbs and emits at certain wavelengths? How many simply reject some of Al Gore's implied but not directly stated consequences? (I believe I read Gavin Schmidt disagreeing with something in the Gore documentary; if so, add him to the list) All WUWT is effectively doing is establishing doubt--not establishing an alternative position, not establishing scientific progress. How many of the scientists in the Senate report agree on the same physical model? Who are these scientists, and what weight should they carry for people who pay attention to survey results? Show me the specific reasons for dissent, and I'll show you why the 500, 700, 1000, whatever list is meaningless. A better question is "what does the list mean to you?" (or to anyone who encounters such things)
  18. SkS Responses to Pielke Sr. Questions
    Although I did not post on this thread -- I would have been completely out of my depth if I had -- I have read every word with great interest. Having a group of people on one side who are generally autonomous, up against a single person -- whatever the merits of the respective arguments -- seems to any onlooker terribly like a pack of wolves attacking a bear. It must have been very difficult for Dr Pielke to handle, especially as the timescale is so compressed and he did provide a lot of his time; which, to some degree, was partly wasted. Overall it certainly left me feeling dissatisfied. Can I suggest that in future, when the opportunity presents itself to interrogate (or challenge?) a key player in the debate, it would be better addressed by an email debate off-line between the SkS authors and the guest. The exchange could then be presented in its entirety as a post. Further comments then made could be answered by the participants of the debate as they see fit. This is just an idea from a film maker who has spent 40 years trying to present such debates in a lively and positive way that leaves the onlooker (viewer) satisfied. To make this work further perhaps the idea could also be extended to 'debates' with other key players, some of whom might not be firmly seen as opponents. I hope the comment helps. Best of luck with it.
    Moderator Response: I believe it will help. Whatever makes for a better experience for our readers and new audience members is welcome advice.
  19. The 2nd law of thermodynamics and the greenhouse effect
    Nope, Phillipe--it just needs to be well-understood by anyone who reads this thread that Damorbel's assertions about the net result of an energy exchange (that energy only flows one way, from a hotter source to a colder source) have been thoroughly debunked about seven bazillion times in the main 2nd Law thread. By the way, Damorbel, how do you explain the simple experiment summarized in video here (50 second mark)? Note that the right jar has the benefit of convective access to the room air.
  20. The 2nd law of thermodynamics and the greenhouse effect
    Re #280 Philippe Chantreau, you wrote:- "You have many times touted around physical laws of which you had not the foggiest understanding." I do think it would be better if you explained just what it is you find incorrect in my postings. A new reader would not easily grasp from your #280 just what my arguements were, let alone what was wrong with them. In short, what information should we gain from #280?
    Moderator Response: [Dikran Marsupial] #280 said very little about what your argument actually is, and I suspect was not intended to. It was a comment on the rhetorical nature of your argument. If you want a concrete example, I pointed out that the fact that the mean surface temperature of Venus is higher than that of Mercury directly refutes an argument you made. However rather than refute the counter example, or admit that your argument was wrong, you ignored it and went back to over-extending an analogy in a way that is not relevant to the dicussion (in a post deleted by another moderator). It should be no surprise that if you ignore counters to the arguments that you have made your actions will be viewed as trolling.

    The information you should take from #280 is that you should change your approach to the discussion and try and take on board the points made by the other contributors, and be less sure that you are right, and virtually every climatologist on the planet is wrong (those are not good odds).
  21. Lessons from Past Climate Predictions: IPCC AR4
    Robert, I guess it depends on your start and end points. Using the 10 years from 2000-2009, the trend is 0.13 (as you state). Using 2001-2010, the trend is 0.067, and using the past 120 months, the trend is 0.015. Using either sets of numbers, the measurements are less than the projection (0.2). In order to meet the projection of 0.2C / decade between 2000 and 2020, GISS temperatures would need to increase at 0.05C / year from now until 2020. It could happenm and as Dana says, it is not 2020 yet.
  22. SkS Responses to Pielke Sr. Questions
    Stephen @157 - we weren't planning on addressing Pielke's "main conclusions." They mostly deal with his emphasis of regional over global climate change, which he incorporated into several of his comments here. I'm not sure if it would add much to the existing discussion.
  23. Lessons from Past Climate Predictions: IPCC AR4
    As the text notes, I used GISTEMP and calculated the trends since 1990 and since 2000. Because it's such a short timeframe, I wanted to maximize the signal to noise ratio, so I included the data through most recent available month, but still provided the trend as °C per decade for comparison. Charlie - yes, the AR4 Scenario A2 model mean trend between 2010 and 2020 is close to 0.28°C. Figure 3 includes the Figure 2 data between 1990 and 2000.
  24. SkS Responses to Pielke Sr. Questions
    @John Cook Captain Jack: The next time that you ask your Torchwood team to chase after a blimp, you will need to equip us with an appropriate number of all terrain vehicles. We know now that it is nigh impossible to catch a blimp by running after it. PS – Our bill for replacement running shoes is in your in-basket.
  25. SkS Responses to Pielke Sr. Questions
    In hindsight, I wish I had gone with my gut instinct and deleted the first five posts of this thread. They created a hostile environment that was not conducive to a frank and opens discussion. To his credit, Dr. Pielke ignored those comments when he made his initial set of posts.
  26. SkS Responses to Pielke Sr. Questions
    dana, Sphaerica's post at 154 reminded me of that list of conclusions in Pielke blog referenced in #1 by Albatross? Might it makes sense to address those in separate summary post since we didn't get around to them? There's a mix of the sensible and the inexplicable in that list Perhaps that could also provide some context for the exchange archived here. John @153. When two people look at a picture and see the same thing it isn't ESP, it's reality. He's got that rope-a-dope style down pat.
  27. Philippe Chantreau at 01:41 AM on 23 September 2011
    The 2nd law of thermodynamics and the greenhouse effect
    Damorbel, do you really think that you can fool anyone here with your nonsense? You have demonstrated in the past, repeatedly, on this very thread, that you are a troll. You have many times touted around physical laws of which you had not the foggiest understanding. You have argued one way, then another, contradicting yourself for the sake of argument. You have lectured others on physics, yet demonstrated a fluency with the science that is best qualified as pitiful. Despite all the asnwers addressed to your confused posts, you don't seem to have learned anything. You are not a skeptic, you are not a dissenting voice, you are just a waste of time. You have benefited of seemingly infinite patience in spite of repeated attempts to start non discussions leading nowhere. You wait for a number of weeks and then do it again. It is not even irritating anymore, it is just pathetic. I have been subjected to snark on SkS, I have endured streams of insults and xenophobic prejudice, I have seen people arguing in bad faith using dishonest rethoric, others laying blanket accusations of fraud with nothing to back them up, but I have never proposed on any forum that someone be permanently banned. I also do not personally know of anyone who was ever banned from SkS. However, I am now convinced that it would be advisable in your case, for objective reasons that will be obvious to the reader courageous enough to peruse your "contribution" (the words feels misused) on this thread. There should be a limit to how much BS can be tolerated for the sake of "balance." You have already passed that limit, in my opinion. I am not in a position to recommend that you be banned but I find it evident that everyone would benefit from it, probably even yourself.
  28. SkS Responses to Pielke Sr. Questions
    Our next post will discuss our questions to Dr. Pielke and his answers. The comments on that post would be a good place to discuss them. We'll probably publish it tomorrow.
  29. Chasing Pielke's Goodyear Blimp
    @John Cook Captain Jack: The next time that you ask your Torchwood team to chase after a blimp, you will need to equip us with an appropriate number of all terrain vehicles. We know now that it is nigh impossible to catch a blimp by running after it. PS – Our bill for replacement running shoes is in your in-basket.
  30. 500 scientists refute the consensus
    This argument seems to be different from one that says many IPCC scientists now dissent. A quote from Watt's blog is below. you can also search "IPCC scientists dissent" and you get many hits. Any comment? "More than 1000 dissenting scientists (updates previous 700 scientist report) from around the globe have now challenged man-made global warming claims made by the United Nations Intergovernmental Panel on Climate Change (IPCC) and former Vice President Al Gore. This new 2010 320-page Climate Depot Special Report — updated from 2007′s groundbreaking U.S. Senate Report of over 400 scientists who voiced skepticism about the so-called global warming “consensus” — features the skeptical voices of over 1000 international scientists, including many current and former UN IPCC scientists, who have now turned against the UN IPCC. This updated 2010 report includes a dramatic increase of over 300 additional (and growing) scientists and climate researchers since the last update in March 2009. This report’s release coincides with the 2010 UN global warming summit being held in Cancun."
  31. SkS Responses to Pielke Sr. Questions
    It looks like Albatross #1 was right - his prediction of Dr Pielke's response style was frustratingly accurate. I found the lack of italics and parenthesis in answering questions which were repeated in the posts - particularly hard to follow. Having said that - it is very hard to conduct a general discussion over many aspects of climate change in this format. I find the targeted topics where two or three participants go at it with charts and specific numbers the most useful in shedding light. Acronymns which are not commonly used should be perhaps explained once by the moderator - but it must be assumed that they be understood by anyone making a useful contribution. Stephen Baines put it well: "There is a "float like a butterfly" kind of feeling to the whole debate, but the "sting like a bee" part never comes" I had exactly that feeling Dr pielke was staying just out of reach in case his opponents delivered a knockout blow.
  32. SkS Responses to Pielke Sr. Questions
    Was this thread ever intended to get as far as the 5 questions SkS posed to Dr. Pielke, and his answers (which are not posted here)? Is there any chance that we will get to go there, with Dr. Pielke's participation?
    Moderator Response: [John Hartz] Here's what I recommend in #138: Because the discourse we had embarked on has been short-circuted by Dr. Pielke's abrupt departure, I move that Dr. Pielke's responses to the questions that Dana posed to him be post as a new SkS article. We can then proceed to analyze those answers on fresh comment thread.
  33. SkS Responses to Pielke Sr. Questions
    Chris, DM and rdr, It could just be his style, but I find Pielke Srs comments very frustrating for many of the same reasons you all point out. Why premise a discussion with a framing based on dichomotomies that you must know people are likely to disagree with? (It's not like it's the first time he has tried that particular framing). Why not try to be succinct when describing how your opinion differs from the person you are talking with? Why not answer questions directly? Why not stay on one topic until it is cleared up? Answering blog comments may not have appeared so onerous if he had been more direct. First, there would have been fewer questions. Second they would have been targeted better. Maybe it reflects his thinking process, but the effect is that he always seems to be positioning his answers somehow - or trying to stay just out of reach of complete comprehension. There is a "float like a butterfly" kind of feeling to the whole debate, but the "sting like a bee" part never comes. When that happens in scientific discussions (and it does sometimes) my guard goes up immediately. I'm thinking to myself, why is this guy prevaricating here? With that question in your head its easy to think less than charitable thoughts when he misrepresents an answer or puts words into mouths. As for the science, there are still so many questions. I still don't understand how his focus on local landuse factors affecting climate relates to patterns in global trends. You still need massive heat imbalances to drive the global patterns, right? I get the sense that he feels that landuse has not got it's due WRT driving regional climate, which might have been true in the past. Seems like a lot of people are trying to do that now, though. In any case, why does that translate into a need to deemphasize the role of GHG? Surely that would only complicate the efforts at modeling effects of local landuse, right? There is a disconnect there. I guess you can say, if there are limited resources the two issues compete with each other, but that's not an argument about the science, that's an argument about policy priorities. Even there, I always thought warming due to GHG actually magnifies the importance of landuse management and sustainability initiatives like REDD, and vice versa. There is common cause and overlap there, not opposition. As for structuring debate, I agree a more structured approach might be needed to deal with the constraints of weblogs as well as to accomodate with argumentation style of guests. An alternative to restricting the discussion to one or two posters might be to pose one specific question per thread. I think John Hartz was posed a hard task having to move discussion onward before discussion of the first question had gotten far. Another approach might be to build a call and response structure into the exchange, so that some time elapses between the guest posts and the responding posts. That might have the advantage of reducing pressure (e.g., Pielke's here now! must post now!) and allowing some steam to blow off between iterations.
    Moderator Response: [John Hartz} Another serendipity moment: While walking our dogs yesterday, I was menatally comparing Pielke's style to Mohammad Ali's. Perhaps there's more to ESP than meets the eye.
  34. Lessons from Past Climate Predictions: IPCC AR4
    I am still trying to figure out how Figure 3 was generated. Dana1981: "We digitized Scenario A2, the red line in Figure 2, and compared it to the observed global surface temperature change as measured by NASA GISS (Figure 3)." But Figure 3 shows an IPCC "projection" starting in 1990. On figure 2, the projections don't start until 2000. Did you use some other source for the data besides Figure 2 to generate the 1990-2010 IPCC projection in your Figure 3 ?
  35. Lessons from Past Climate Predictions: IPCC AR4
    Dana1981 -- We now agree that the 2000-2020 IPCC projection for scenario A2 is 0.2C/decade. You also assert that the projection is 0.12C/decade for 2000-2010. Does this mean that the IPCC projection for 2010-2020 is 0.28C/decade ? In case you don't understand where the 0.28C/decade comes from, I'll point out that IPCC projection 2000-2020 is 0.2C/decade or 0.4C rise. You claim the projection (or in a later comment "the model mean") is 0.12C for 2000-2010, for a rise of 0.12C. This leaves a required rise of 0.28C in the coming decade to match the IPCC projection.
  36. SkS Responses to Pielke Sr. Questions
    Dikran, rdr95, I agree totally with each of you. That was rather the point of my first paragraph. However the way the thread developed (and this isn't a criticism but a reminder that these interactions occurred on a blog comment board!) necessarily gave Dr. Pielke an awful lot to deal with. The large amount of posts awaiting Dr. Pielke whenever he returned here made it very easy for him to choose those posts he felt comfortable addressing. In my opinion this produced a "more heat than light" style of discourse than might have occurred if there was a steady and thoughtful dialogue between Dr. Pielke and one or two of the "in house" posters who might manage the response of others.. I agree with rd95 that the weight of evidence is very much against Dr. Pielke's points of view (as expressed here) and it's obvious that quite a bit of Dr. Pielke's assertion lacks a thoughtful evidence base (e.g., and paraphrasing, "money spent on modeling is a waste of time and should be spent on basic research on novel technologies"; "discussion of so-called "climate sensitivity" is an almost meaningless activity" and other bits of "pub talk"). But it wasn't really possible to address these and other assertions very thoughtfully in the context of a snowstorm of posting...that's my opinion, and if this were to be repeated, it might be worth thinking of a way of better accommodating the "visitor"!
    Moderator Response: [grypo] chris, I see your point. It's fair criticism that SkS can take under consideration for future use if this type of situation arises again. While this began and ended on poor terms, in the middle, some important agreements and disagreements popped up that we hope to highlight soon.
  37. Lessons from Past Climate Predictions: IPCC AR4
    Jonathon#11: 120 months (10 years) is not long enough a period to establish a meaningful trend.
  38. Lessons from Past Climate Predictions: IPCC AR4
    "My mistake. I meant to say 120 months, and the number is correct in degrees / decade." Well, I just looked at Wood For Trees, put in 2000-2010 (which is what was discussed, not the last 120 months, btw), and the linear trend came up as 0.0128317 per year, which comes to about .13*C/decade. I'm not sure of what I need to do to get the .15*C, but it certainly isn't close to .015*C/decade. Edit: 2000 thru the end of 2010 comes to .15*C/decade, so that might be what was implied (though that is 11 years, not ten). "Even a cursory look at figure 3 above will tell someone that the first decade experienced much greater warmer than the second." And yet adding the last ten years of data actually raises the linear trend; 1990-2000 has a linear trend of 0.0167924*C per year while 1990-2010 has a linear trend of 0.0189468*C per year. The eyecrometer doesn't always tell the truth.
  39. Lessons from Past Climate Predictions: IPCC AR4
    Robert, My mistake. I meant to say 120 months, and the number is correct in degrees / decade. The value of 0.15 / decade is not supported by the GISS data. Even a cursory look at figure 3 above will tell someone that the first decade experienced much greater warmer than the second.
  40. Lessons from Past Climate Predictions: IPCC AR4
    Jonathon, so... you are disputing the claim that the observed temperature trend over the period from 2000 to 2010 was 0.15 C by citing the past 60 months. You really can't see the flaw in your reasoning there?
  41. Lessons from Past Climate Predictions: IPCC AR4
    Jonathon #8, The GISS trend from 1990-2000 (about .17*C/decade) is actually smaller than the trend for 1990-2010 (.19*C/decade). The warming did not stop in 2000. "Calculations using GISS monthly data yield a linear slope of +0.015C / decade for the past 60 months." That's only the last 5 years. And the number given is trend per year, not decade. That comes to about .15*C per decade.
  42. SkS Responses to Pielke Sr. Questions
    @149 Perhaps the real problem was not the number of posters, but the relative weights of the scientific data supporting one 'side' or the other. If one party refuses to acknowledge the weight of the data held by the those who differ from that party, things are bound to get acrimonius - even at a scientific conference (and yes I have seen that plenty of times). If you have a large majority of climate scientists producing data that support an hypothesis over many years, and yet a few hold out (without offering much in the way of data supporting alternative hypotheses), rational discussions with the latter become very difficult.
  43. Dikran Marsupial at 22:05 PM on 22 September 2011
    SkS Responses to Pielke Sr. Questions
    Chris I don't think anyone would expect Prof. Pielke to respond to everybodys questions. However one would expect that where he did respond he would actually attempt to answer the question. See the responses (here and here) he made to the direct question I posed (here), and you will see that it would have taken him far less time to simply answer the question (a simply "yes" or "no" would be a good start) than to avoid giving a direct answer in the way that he did. This suggests that the large bandwidth of the discussion was not a key factor preventing the exchange of scientific information.
  44. Climate sensitivity is low
    In the Pielke Sr thread, dana1981 says: "I think I'm most disappointed that we never got an answer regarding the discontinuity between low climate sensitivity arguments and the paleoclimate record. I've never seen any low sensitivity proponent answer this question, and unfortunately it seems Dr. Pielke was unable to answer it as well." Also a long time ago I promised scaddenp I would address low sensitivity, and this is a start. The portion of Knutti and Hegerl (2008) that goes with "Advanced" figure 4 (click on Advanced tab above) (Various Estimates of Climate Sensitivity) is shown to the left.

    I labeled the 3 paleo sensitivity estimates in question. The problem arises from the red squares in the first column "similar climate to base state". The key question is how well can the dissimilarity be accounted for in the models. Specifically, the 8C rise from the last glacial came from combination of Milankovitch forcing, dust feedback, CO2 feedback, and other feedbacks that are modeled and equate to a 3C (best estimate) for 3.7 W/m2 of forcing. However, the leftmost red square is red because there are lots of unknowns compared to the present. There are many complications for modeling. In http://www.rem.sfu.ca/COPElab/Claquinetal2003_CD_glacialdustRF.pdf Claquin et al posit one of the factors in ice age transitions have an added factor, namely dust, that adds long term positive feedback. Less dust means higher SST but also less fertilization so less algae and more CO2 all adding to the warming. In short, there is a higher sensitivity for glacial to interglacial compared to today. Here is a general complication. A large sensitivity difference also arises from ice and snow albedo changes. During the ice age the ice and snow reflect a lot more sunlight and as it melts the surface albedo decreases as a positive feedback. The feedback is obviously higher than for the present climate which has a lot less snow and ice. The problem in determining the difference comes from highly nonlinear responses to Milankovitch forcing compared to today's CO2 forcing. Here's just one example: http://envsci.rutgers.edu/~broccoli/reprints/Jackson+Broccoli_ClimDyn_2003.pdf The modeling attempts to account for numerous differences from the modern climate including THC and sea ice, poleward heat transport and temperature gradient, precipitation changes, etc. All of these will be radically different with 3.7 W/m2 of CO2 forcing. Most point to a much larger feedback from Milankovitch forcing due to seasonal, geographic, and ice age climate differences.

  45. SkS Responses to Pielke Sr. Questions
    This has been an interesting exercise and I have a couple of comments. As a working scientist I have lots of interactions with other scientists - we discuss things informally, at meetings, by phone/Skype/email and so on. One of the things that characterises these discussions is that people say what they mean, answer questions in the spirt these were asked (i.e. genuine attempts to seek and convey information) and so on. Attempts at beating around the bush, obfuscation, redirecting the question with inappropriate response are extremely obvious and create a very poor impression. If anyone reading the comments here think that what they've read accords with common scientific discourse they are quite wrong. On the other hand this is a blog comment board! Dr. Pielke is in a difficult situation here, and this leads to a possible way of addressing these sorts of discussions should they arise in future. Dr. Pielke was inundated with comments, and it's not fair that he should be expected to address everyone's comments. A possibility for doing this in future would be for the "visitor" to interact with only one or two posters, and some scheme set up (a "dummy thread" say or simply using email) whereby comments to any another Dr. Pielke that takes the opportunity to present his/her point of view are channeled through one or two members of this site. This would have the advantage in making for a much more coherent interaction, with far fewer posts for the visitor to address, and rather more time to think in between posting. In my experience the latter is hugely important in posting properly sensible comments blog boards.
  46. The 2nd law of thermodynamics and the greenhouse effect
    Re #278 When you write "The paragpraph about what happens if I die is irrelevant (and another example of over-extending an analogy)." you illustrates the matter in hand exactly. This is further exemplified by the perhaps more relevant comparison I made with the Sun when I wrote:- "But they are not relevant to the Earth which, at the most, sources 0.1W/m^2 in comparison with the Sun (6.3x10^7 W/m^2)." Do you not agree that the 0.1W/m^2 produced by the Earth, mainly by U238 and K40 has almost no affect on its surface temperature? With this 0.1W/m^2 the Earth would have a temperature of about 50K, whereas your stars are producing somwhere about 6.3x10^7 W/m^2. Think of it this way: it doesn't matter where a particular star is found, it produces it own heat which determines its temperature; whereas a planet's temperature is strictly related to is distance from the star; an extreme example is a comet which has a very variable temperature, only warming up for a short period while close to the Sun. The Earth would have a similar temperature cycle if it shared a comet's orbit whether it had a CO2 atmosphere or not. The relevance of this is the star's temperature is independent of its position in the same way the temperature of your body, wrapped in insulation, is substantially independent of its position; but strongly dependent on the amount of (internal) heat (150W) it generates and the amount of insulation surrounding it. I am bothered that you do not appear to see the comparison between the temperature of a body (or a star) generating internal heat and a planet (or a dead body) that does not generate any internal heat. This is not playing games like trolling, as you seem to think, but it is serious science, the point I am making between heat generated internally (or not, as the case may be) is quite serious and is at the heart of a discussion, while you only see as me attempting to disrupt the discussion. I am very sorry if you feel I am just [trying] :- "to waste the time of others by engaging them in conversations that lead nowhere". This is certainly not the case and I am sorry if anything I have written gives that impression but I stand by the facts I have recounted, heat originating inside a body, any body, has a quite different effect than heat arriving from outside it.
    Moderator Response: [Dikran Marsupial] I'm sorry, but this discussion is going nowhere. Nobody disputes that the ultimate source of the heat in the atmosphere is the Sun and that the heat generated from within the Earth by e.g. radioactive decay is insignificant. Nobody is disputing either of these facts, and neither has any relevance whatsoever to a discussion of the application of the second law of thermodynamics to the greenhouse effect. Hence you are deflecting the discussion of the substantivie issue with digressions of issues that are not contested and which have no relevance. That is indistinguishable from trolling.

    You are incorrect if you think that a planets temperature is strictly related to its distance from its star and that the presence of CO2 makes no difference. This is directly refuted by the observation that the surface of Venus is warmer than the surface of Mercury.

  47. Lessons from Past Climate Predictions: IPCC AR4
    I am a little puzzled by the stated observed value also. From where are you getting your temperature data? Calculations using GISS monthly data yield a linear slope of +0.015C / decade for the past 60 months. Perhaps there was a decimal error. Averaging over a tweny-year period to obtain a value for the previous decade seems questionable, especially when the warming occurred in the first decade.
  48. Lessons from Past Climate Predictions: IPCC AR4
    Thanks, Dana Maybe I'm slow, but how was the observed 0.15°C per this decade calculated? What's the trend with more datasets, using same calculation? Perhaps a link in the post could help.
  49. SkS Responses to Pielke Sr. Questions
    [inflamatory/ad-hominem snipped] Has Pielke Sr. written a review paper on regional land use change and its effects on climate? I haven't looked... but it is only there that I would expect editorial tradition to require a comprehensive view of his and other people's contributions. On a up note, several of the statements that Dr. Pielke made here would surely not be greeted with enthusiasm at sites like WUWT, being too ready to act on reducing CO2, and someone with a puckish sense of humour might have a good time poking the denier sites with those quotes.
    Moderator Response: [Dikran Marsupial] Please limit the discussion to Prof. Pielkes arguments and avoid criticism of the person.
  50. The 2nd law of thermodynamics and the greenhouse effect
    Re #277 "Moderator Response: [Dikran Marsupial] You are incorrect and would benefit from considering the advice you are given in more detail. Consider a binary star, one a blue giant, the other a normal main sequence star, much like our own Sun. Clearly the blue giant is the hotter and will have a warming effect on the other star because the NET transfer of heat will be from the blue giant to the main sequence star." I would agree with you if the Earth was a significant source of energy like either the red or the blue stars you refer to. But they are not relevant to the Earth which, at the most, sources 0.1W/m^2 in comparison with the Sun (6.3x10^7 W/m^2). The temperature of the stars you refer to are surely determined by the energy they source from (local) internal nuclear reactions (do you agree about this?) whereas the temperature of Earth is decided by the temperature and distance of the Sun. Further you write "If I put on an extra blanket at night I warm up, but there has not been a net transfer of heat from the blanket to my body " Like the red and blue stars your body is a heat source (about 150W in total for a live but resting body). Blankets slow the rate this internal heat escapes to the surroundings, meaning your body is, due its internal heat, at a temperature above that of the surroundings. If you die, your 150W comes to an end and your body temperature will fall to that of the surroundings, slowly if it is well insulated by blankets, quickly if uninsulated. Thereafter your body temperature, insulated or not, will follow the environmental temperature. I have mentioned this before, do you think it is incorrect? I'd be very interested to hear another explanation. Sorry, I do not understand cryptic expressions like 'DNFTT'.
    Moderator Response:

    [Dikran Marsupial] The Earth is a significant source of heat with respect to the atmosphere, which was the point. Solar radiation (mostly visible) heats the surface, which then emits IR that heats the atmosphere. However the atmosphere does emit IR downwards to the surface and hence there is a transfer of heat from the atmosphere to the surface, but it is smaller than the transfer from the surface to the atmosphere (hence it the laws of thermodynamics are not violated).

    The example of a binary star was to demosntrate that there is a bidirectional transfer of heat between any two objects above zero degrees Kelvin, but the net flow is from warmer to cooler. Over-extending an analogy beyond what it was intended to show is a common rhetorical tactic to avoid taking on board the substantive point. Please go back and think about the analogy in the light of what I have just written.

    Yes, the heat source for the blanket example is the body, which is very apposite to a discussion of the greenhouse effect. The sun does not substantially warm the atmosphere (which is largely transparent to visible light). It warms the surface, which then emits IR which does warm the atmosphere. From the point of view of the atmosphere, it is not being warmed from above by the sun, but from below by the Earth. The fact that the Sun is the source of the Earths heat is irrelevant; the sun is ultimately the source of the heat from my body under the blanket as well.

    The paragpraph about what happens if I die is irrelevant (and another example of over-extending an analogy).

    DNFTT means "do not feed the troll". Repeatedly bringing up the same points again and again that have been answered already many times, is indistinguishable from trolling. If you want to dispell the appearance of trolling, you need to engage with the explanations you are given, rather than just seeking to over-extend analogies etc.

    [DB] As for "DNFTT" that is an acronym for "Do Not Feed The Trolls". It is a suggestion given to the regular participants in an online forum when a newcomer has clearly established 2 things: 1. That they have no interest in actually learning about the topic and 2. Their continued participation in the forum is an exercise designed to waste the time of others by engaging them in conversations that lead nowhere. Similar to Napolean's efforts in Russia or the Soviet's efforts in Afghanistan.

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