Is it 98% or 97%?

The latest “sticky” Watts Up With That (WUWT) post is one claiming that, in fact, the results of the Cook et al. (2013) consensus surveys suggests that 98% of the papers that take a position on anthropogenic global warming (AGW) endorse AGW, not 97%. The reason this is significant, according to Anthony Watts, is that this indicates that Cook et al. so desperately wanted to match previous reults (which reported a 97% consensus) that they engineered their results to reproduce this outcome.

Really? That seems quite remarkable. Could it possibly be true? Below is the table from the Cook et al. paper. In the Cook et al. paper, they find 3896 + 78 + 40 = 4014 articles that take a position on AGW (endorse, reject or uncertain). Of these papers, 3896 endorse AGW and hence 97.1% of the papers that take a position on AGW, endorse AGW. Anthony Watts seems to be suggesting that only 3896 + 78 = 3974 papers take a position on AGW (i.e., those that are explicitly uncertain should not be included) and hence the correct result is 98% of those that take a position on AGW endorse AGW.
Anthony Watts is just basically wrong. The paper is very clear that the study distinguishes between those papers that make no mention of AGW and those that do and divides those that do into those that endorse, reject or are uncertain. Rather than finding an error that should have been “caught in peer review“, this just makes Anthony look like a pedantic twerp who desperately wants to find something wrong with the Cook et al. (2013) study and, so far, is failing to do so.

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13 Responses to Is it 98% or 97%?

  1. Sou says:

    It’s funny when you think about it. Anthony arguing that the consensus is higher than stated.

  2. That is rather amusing. I am, however, now slightly confused about the 40 ‘uncertain’ abstracts. A comment by Richard Tol on WUWT has suggested (and the paper seems to confirm this) that the 40 ‘uncertain’ abstracts are from a randomly selected sample of 1000 abstracts that were initially rated as ‘no position’ – a total of about 7930 abstracts. If this is the case then is this 40 out of 1000, or is 40 out of 7930 – i.e., did they assess these 1000 abstracts, find 5 that were uncertain and then correct for the sample being bigger than 1000?

  3. Wouldn’t 98% have been a perfect number for Cook et al.? The 97% comes from an old study and one of the other results of Cook et al. is that the consensus has been increasing during the study period. It is hard to get much higher, but a higher value as 97% would have fitted nicely.

  4. Sure, I find it very strange that they’re being criticised on WUWT for reporting a 97% consensus when it should have been (according to WUWT) 98%.

  5. Do you know Orgels second rule: “Evolution is cleverer than you are.”

    I know you would like to keep the discussion civilized, but I would add the rule:

    Climate ostriches are always weirder than you think they are.

  6. I suspect that you’re right. I’m not trying to “keep the discussion civil” because I think it will necessarily make a difference. It’s mainly because it just seems to be somewhat different to other blogs addressing “climate denial”. It may not be particularly effective, but it seems worth a shot.

  7. Dana has confirmed on Twitter that it was 5 out of 1000, extrapolated to 40 out of 7970.

  8. Gavin's Pussycat says:

    But the one implies the other!

    If 98% of the papers that take a position on AGW endorse AGW, then a subset of 97% does also. Any subset of 97% 🙂

  9. dana1981 says:

    Note that we did have a 98% result as well. The AGW consensus was stated in 97% of papers, but among 98% of abstracts’ authors (because consensus papers had more co-authors than rejection papers). We focused on the 97% figure because we’re most interested in what the peer-reviewed research says.

    It’s funny because I thought that was the conservative decision. We didn’t even think about choosing the 97% to match previous studies. That’s just the result that came out. I think there’s a lot of psychological projection going on in suggesting we had some sort of diabolical motives.

  10. I think, strictly, speaking the difference depends on what you count as a paper that takes a position on AGW, but you do have a point.

  11. Thanks for the comment. Indeed, there were clearly many ways to present the results. The whole 98% versus 97% debate is all a little odd and somewhat contrived to make it – as you say – seem as though it was engineered to suit some kind of agenda, rather than simply one of the results of the analysis.

  12. Gavin's Pussycat says:

    Actually I meant it for humoristic relief, not as a “point” 🙂

  13. Yes, I thought that might have been the case 🙂

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