Comments 1 to 20:

1. Tom Curtis at 21:55 PM on 18 July, 2012

   "Remember that in 2000 we had already experienced ~0.8°C surface warming, so these answers are equivalent to 70+% of participants answering that equilibrium climate sensitivity is ~2-4°C for doubled CO2, and only about 8% answering that it's lower than ~2°C, with a further ~20% answering that sensitivity is higher than ~4°C."

   Actually, the question posed was regarding the expected temperature if and when the CO2 concentration reached 550 ppmv. Technically, the temperature achieved when the atmosphere reaches a certain concentration would be the Transient Climate Response rather than the Equilibrium Climate Response. As such, the natural interpretation of a TCR of 1.8 to 3.8 C per doubling of CO2 is truly remarkable. I suspect, however, that most respondents would not have known the distinction between TCR and ECR; and that consequently the answer does represent the expected ECR. A significant number of respondents are, however, likely to have known the difference. The probability is that a significant portion of respondents did understand the question. If a significant number of respondents took the question to be about the TCR, that would introduce a significant low bias to the results.
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2. Bernard J. at 00:13 AM on 19 July, 2012

   "I suspect, however, that most respondents would not have known the distinction between TCR and ECR; and that consequently the answer does represent the expected ECR. A significant number of respondents are, however, likely to have known the difference. The probability is that a significant portion of respondents did understand the question. If a significant number of respondents took the question to be about the TCR, that would introduce a significant low bias to the results."

   I'm pleased to see this point raised immediately after the original post. My first thought on reading it was whether the figure to which Tom refers demonstrates a vaguely positive skew, which would suggest a bias toward a low estimate for ECR, and although there is a slight possibility of such the coarseness of the histogram makes fraught any reasonable non-null conclusion. Another option would be if there'd been a bimodal distribution, but again the coarseness of the categorisation makes it impossible to detect. It suggests refinement for any future survey.
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3. Bernard J. at 00:20 AM on 19 July, 2012
   By "refinement" I mean that future surveys might explicitly ask questions about participants' understanding of climate response, and not merely provide more categories with which third parties might attempt to infer the understanding of the respondents!
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4. Tristan at 00:47 AM on 19 July, 2012
   I think Q3 was a curveball. On top of the 'how much of the 550ppm warming was already realised by 2000 dilemma', TCR assumes the doubling is a result of a steady rate of CO2 increase (1%p.a.) over ~70 years. 275 - 550 will have taken longer than 70 years wont it? That'd imply that 275-550 would be slightly higher than TCR. Furthermore, TCR is not simply the surface temp anomaly relative to 70 years prior. This is only true if all other variables are held equal. The size of the anomaly vs -70yrs is heavily influenced by what level of sulfates we're still emitting by that point. If we've cleaned up our act, the 550ppm anomaly will be likely higher than the TCR. If we're still dirty, likely lower. I don't think many people would be able to give a numerical estimate to Q3 with much confidence, but 1-2C seems by far the most likely answer according to the current state of climate science.
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5. Andy Skuce at 02:05 AM on 19 July, 2012
   In many ways, the last question was a policy and economics question and was therefore beyond the expertise of most of the scientists involved It does show, though, that the scientists, without exception, do not believe in any existing technological silver bullet that will solve the climate crisis without government policy changes. That should at least give pause to the "rational optimists" out there who believe that we can muddle through this problem without involving government in a major way.
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6. dana1981 at 03:50 AM on 19 July, 2012
   Good point about the "if and when" wording in Q3. I added a bit of text to the post noting that answers may have referred to TCR or ECS, depending on how they interpreted the question. I can't recall my answer, but I suspect I said 1-2°C based on the "if and when" wording.
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7. threadShredder at 03:19 AM on 20 July, 2012
   You should update the myth on this topic with the results of this study.
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8. dana1981 at 06:23 AM on 20 July, 2012
   You mean the 'no consensus' myth, threadShredder? I was actually thinking about that this morning. I'll try to remember to update it this weekend.
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9. threadShredder at 03:50 AM on 21 July, 2012
   Yes, dana, that one. I think it would be very helpful to new folks for post writers to incorporate as many new posts as possible into the myths, according to appropriateness, of course. That is, if the writers of the new posts are aware of the totality of the myths topics, which I assume most are. Just providing links in the myth pages can help tie in new stuff to the myth topics, and give new folks like myself more continuity (if that makes any sense).
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10. dana1981 at 04:20 AM on 21 July, 2012
    We do try to update the myths database with information from new blog posts, when relevant. When we do so we usually add a note to the bottom of the blog post noting that we've updated the myth rebuttal.
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11. dana1981 at 04:48 AM on 21 July, 2012
    Note by the way that Anthony Watts has enlisted his minions to ruin the second round of the Vision Prize. Ironically, the second round is about the Arctic sea ice decline, which is a subject on which WUWT reader predictions have an absolutely abysmal record.
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12. threadShredder at 05:51 AM on 21 July, 2012
    Yes, I know about the updates. But I've noticed some posts could have been integrated or at least linked in some of the myths and weren't. I understand this is a voluntary effort from posters, and that the volume of material precludes any sort of comprehensive effort on single contributors. Given that, my suggestions are simply to suggest some inclusion if they are appropriate and may have been overlooked by busy people. I appreciate the site a lot, and wish I could be of more help, but I'm still a novice. Have been through all the myths and making my way through the posts as time allows. The site has come in quite handy for internet spats with deniers.
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13. Bernard J. at 17:05 PM on 21 July, 2012
    Dana1981 at #11: Watts appears to be demonstrating a serious case of inability to understand context. The Vision Prize is clearly targetted at a particular (expert) grade of professionals trained in climate change science, and yet Watts takes umbrage at the fact that there is an assessment process to weed out non-qualified attempts to sign on.

    It will be interesting to see if they are biased or open and whether I get to join the “players”. I urge WUWT readers to sign up and report your acceptances or rejections below.

    Why does he think that any joe from the streets should be allowed to contaminate the responses? The point is to garner an understanding of the opinions of the best-informed people in the world, and not from people who not only have no understanding, but who are actively motivated to oppose the directions and implications of reasoned understanding. As I noted in a post at Tamino's, to hold this perspective of what constitutes reasonable behaviour one would require a total absence of shame.
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14. Bernard J. at 18:18 PM on 21 July, 2012
    I've just done something that I have not done for a long time, and read the Wattsian comments on Dana's first link at #11. Big mistake. I despair for humanity, if that mob is representative of the lay community. What does it say about us, that educated and trained people understand the universe in one way, and so much of the laiety crowd in layers on top of each other at the opposite side? I sincerely hope that the Vision Prize organisers have the presence of mind to purge their surveys of the contamination introduced by Watts.
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15. John Hartz at 01:26 AM on 22 July, 2012
    Bernard J: With all due respect, the "mob" posting on WUWT is an insignificant fraction of the human population.
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16. dana1981 at 01:34 AM on 22 July, 2012
    Bernard J @13 - to be fair, the Vision Prize isn't limited to climate scientists, but also includes individuals "with relevant scientific or technical credentials," for example. That's how I was able to participate, as an environmental scientist with a physics background. I suspect Watts might qualify with his meteorology background, though as I recall he doesn't have a degree in the subject? I also echo John Hartz @15 in that WUWT commenters are the radical fringe, not at all representative of the general public.
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17. dana1981 at 02:09 AM on 22 July, 2012
    As now noted at the end of the post, the 'no consensus' rebuttal has been updated to include the Vision Prize results.
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18. Bernard J. at 13:37 PM on 23 July, 2012

    I also echo John Hartz @15 in that WUWT commenters are the radical fringe, not at all representative of the general public.

    Dana and John. I certainly acknowledge that Watts' commenting fan-base is over-sampling from the extreme end of the anti-science pool. My concern is that they have a disproportionate influence in policy, and this was increased recently as a result of an off-the-cuff straw-poll a colleague conducted of non science-specialised students. Around a third believed that there was a serious scientific debate about the evidence for climate change, and of those a majority thought that the science had been done incorrectly or was compromised by personal interest on the part of scientists. Most of the students referred to "the internet" as a source for their doubts of the science. Whether this is more representative of such students generally still has us scratching our heads... Amongst my non-tertiary educated friends and relatives there is a strong propensity to believe that there is no smoke without fire in tabloid stirring of the idea of a debate about the science of climate change. It's classic fear, uncertainty, and doubt. I'm sure that they're not as extreme in their beliefs as the Watts crowd, but the issue is whether they let the fundamental notion of the 'unreliability' of the science influence their decisions when voting and 'consuming'. The overall glacial pace of government action around the world would seem to reflect this. In the Australian context I guess that one test of the general public's ability to balance the realities of climate science against the tabloid 'uncertainties' will occur at the next federal election. One counter to the FUD campaigns of the blog science-denial industry is the presence of initiatives such as the Vision Prize, and I certainly hope that they are able to separate the denial noise from the surveying of the signal of scientifically-qualified opinion.
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19. dvaytw at 02:57 AM on 12 November, 2012
    Quick question: why 250 years?
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20. dana1981 at 05:47 AM on 12 November, 2012
    dvaytw @19 - the IPCC looks at changes since 1750 (approximately 250 years) - I think it's just chosen as a reasonable "pre-industrial" date.
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