Several months ago Cook et al. released a paper in which they analysed the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature.

What they did in that study is examine 11,944 abstracts from 1991 to 2011 that included the words “global climate change” or “global warming” in their abstract. What they found after analysing these abstracts is that among those that expressed a position on global warming, 97% endorsed the consensus position that humans are causing global warming.

Not a surprising result at all as this was a bigger literature survey than the one done by Oreskes in 2004. It found that all the selected abstracts (928 in total) that stated a position on the cause of global warming said humanity is to blame.

When you survey climate scientists you find a similar agreement on the cause of global warming of 97 to 98% amongst publishing climate experts (Doran and Zimmerman 2009) You see the same pattern when you analyse public statements of climate experts (Anderegg et al. 2010). When you take a look at how this consensus evolved from 1996 to 2009 you see a steady increase in the agreement among scientists (Bray 2010). All this is driven by the evidence we have and the research that is available in the literature.

Of course you see exceptions to this, as you might have noticed I was talking about “climate experts” and “publishing climate experts”. As soon as you start moving away from climate scientists who do research on global warming and climate change the picture changes. The less relevant a field is compared to climate science the lower the acceptance is that we are causing our climate to change. One of the lowest you’ll find among economic geologists, only 47% of this group saying that humanity is the cause for global warming.

This drop in the level of acceptance of the evidence we have is in part due to not being as familiar with the subject, but ideology also plays a role. How big a factor ideology is varies, but it can be so strong that you outright reject anything that contradicts your ideological position. Which brings me to Anthony Watts and one of his latest blog post called ‘The 97% consensus myth – busted by a real survey‘ (archived here).

In his blog post Watts talks about a survey held by the American Meteorological Society among its members. This survey found that just 52 percent of survey respondents answered that global warming is happening and it’s mostly us. Not a surprising result if you’re familiar with previous surveys like Doran and Zimmerman 2009 which found that this was 64% among meteorologists.

Table 1. Meteorologists’ assessment of human-caused global warming by area and level of expertise. Figures are percentages rounded to the nearest whole number. Numbers in the bottom four rows represent percentage of respondents giving each possible response to the follow-up email question, including non-response to the email (labeled “insufficient evidence – unknown”). These responses together add to the same number as displayed in the insufficient evidence (total) row; some differences occur due to rounding. Similarly, columns total to 100% if all numbers except those in the bottom four rows are added, and differences from 100 are due to rounding. Although 1854 people completed some portion of the survey, this table only displays the results for 1821 respondents, since 33 (less than 2% of the sample) did not answer one or more of the questions on expertise and global warming causation.

Though I don’t find these results surprising, I do find them troublesome. Our weather reports are presented to us by meteorologists, often the weather man you see on TV is one. This is troublesome as they are the ones that put into context why certain weather events happen. If this group doesn’t accept the science we then have a communication issue towards the public on what is and isn’t cause by global warming. This can seriously hinder our ability to have a good and informed public discussion on what we want to do as a society.

But lets return to Anthony Watts and the image he uses to start his blog post with:

The only response to this image that I can give is the following: it’s nonsense.

Watts is comparing two vastly different things here. He’s comparing the scientific consensus that was found in the scientific literature to an opinion survey among meteorologists who might not even do any research; these are two vastly different things. What this also ignores is that expertise matters. Remember the table from the survey that I showed you a little while back?

This is what the survey says about it:

Climate science experts who publish mostly on climate change, and climate scientists who publish mostly on other topics, were the two groups most likely to be convinced that humans have contributed to global warming, with 93% of each group indicating their concurrence. The two groups least likely to be convinced of this were the non-publishing climate scientists and non-publishing meteorologists/atmospheric scientists, at 65% and 59%, respectively. In the middle were the two groups of publishing meteorologists/atmospheric scientists at 79% and 78%, respectively.

What this means is that those with the relevant expertise confirm the consensus in the scientific literature. This is because they are aware of what’s in the literature and have based their position on the evidence. So this survey confirms the consensus, it doesn’t undermine it.

But this is me nitpicking compared to the other mistakes in Watts’ blog post. One of which is this (lifted as is from his blog post):

We’ve all been subjected to the incessant “97% of scientists agree …global warming…blah blah” meme, which is nothing more than another statistical fabrication by John Cook and his collection of “anything for the cause” zealots. As has been previously pointed out on WUWT, when you look at the methodology used to reach that number, the veracity of the result falls apart, badly.

No, it doesn’t fall apart. What Watts is referring to is a Facebook response from Bjørn Lomborg and a letter by Richard Tol he published on his blog. I already have a response to this blog post on my website called ‘Cook’s 97% Climate Consensus Paper Doesn’t Crumble Upon Examination‘. Please read that for the full context, but I’ll lift the following relevant part from it:

[O]ne of the co-authors, Dana Nuccitelli, wrote a blog post putting some of the criticism in context; showing that they didn’t have merit. To this day he’s still addressing criticism towards this paper, most of it just puzzles me why they are made.

For example yesterday Anthony Watts again attacked this paper on his blog Watts Up With That (WUWT). The blog posts starts with a copy of what Bjørn Lomborg wrote about the Cook et al. paper on facebook. It repeats a lot of the already addressed criticisms towards the authors, which we already know have no merit. There were a few new details in there but Wotts has already talked about those.

A lot of accusations are made in that letter towards the authors but it mostly boils down to the claim that data is hidden. And that this hidden data is needed to verify that the results of the study are valid. With a good dash of speculation and other accusations towards the authors of the paper.

However, there’s a problem with the accusation that data is hidden. How the abstracts were rated and how results were analysed are available in the paper. Also all the data you need to replicate the results are available. You can download it from the very same page this paper is hosted on (it’s linked under supplementary data).

It gives you everything you need to see if there are problems in the methodology they used or if they for example incorrectly rated papers. Any serious problems in Cook et al. paper will be detected if you use that data and see if you can replicate the results.

But Tol isn’t doing that. He wants every little piece of data no matter how irrelevant it is to checking if the results they got are correct. And if it isn’t given for whatever reason he accuses the authors of hiding data and speculates on the motives as to why this might be.

But here’s the main issue I have with the blog post that Watts wrote:

You see, it turns out that Cook simply employed his band of “Skeptical Science” (SkS) eco-zealots to rate papers, rather than letting the authors of the papers rate their own work. The result was that the “97% consensus” was a survey of the SkS raters’ beliefs and interpretations, rather than a survey of the authors opinions of their own science abstracts.

[…]

Most people who read the headlines touted by the unquestioning press had no idea that this was a collection of Skeptical Science raters opinions rather than the authors assessment of their own work. Readers of news stories had no idea they’d been lied to by John Cook et al.

I normally don’t do what I’m now about to do, as it can derail productive exchanges. I also tend to give people the benefit of the doubt. It’s why I’ve so far only done it once, so this will be the second time:  Anthony, you’re a liar.

Let me quote myself from my blog post ‘97% Climate consensus ‘denial’: the debunkers again not debunked‘ which is also a response to something published on Watts Up With That:

They also contacted 8,547 authors to ask if they could rate their own papers and got 1,200 responses, which meant that 2,142 papers were also rated by their authors on their endorsement level. The results for this again found that 97% of the selected papers stated that humans are causing global warming. This was done to determine that there wasn’t any sort of inherent problem in the rating system used and this seems to indicate that.

Yes, you read that right. The very paper Watts linked to in his blog post states that the authors of the selected abstracts were asked if they could rate their own papers. Which again found the 97% consensus number.

He also has several blog posts on his website that mention this. The letter written by Richard Tol is one post that refers to this. It’s directly mentioned by Christopher Monckton in the blog post ‘Join my crowd-sourced complaint about the ’97% consensus” (archived here). This very point was also mentioned by Cook, Nucitelli, and many others in their responses to Watts. Same goes for the comment sections on Watts’ website. There’s no way he wouldn’t know this as this is already mentioned in the abstract of the Cook et al. paper (or he doesn’t read what is published on his website, but I find that highly unlikely).

He also restated this position in the comment section of his blog post by saying this to a commenter (archived here):

Bryan, This response suggests you are simply concern trolling. Had Cook actually done an honest survey, we’d have the opinions of the authors about their papers, not the opinions of the SkS pal review squad in place of those opinions.

The blog post was eventually changed to acknowledge that authors were asked if they could rate their own papers. But it wasn’t via an apology or an honest correction. The text I quoted earlier now reads as follows (I’ve bolded the changes, you can find the new version archived here. The page he links to is archived here.):

You see, it turns out that Cook simply employed his band of “Skeptical Science” (SkS) eco-zealots to rate papers, rather than letting all authors of the papers rate their own work (Note: many authors weren’t even contacted and their papers wrongly rated, see here). The result was that the “97% consensus” was a survey of the SkS raters beliefs and interpretations, rather than a survey of the authors opinions of their own science abstracts. Essentially it was pal-review by an activist group with a strong bias towards a particular outcome as demonstrated by the name “the consensus project”.

His response is to link to a debunked claim that papers were wrongly rated. The authors of the Cook et al. paper already dealt with that particular claim. Many of the authors that claim to be wrongly rated either weren’t and/or were invited to self rate their papers (which they hadn’t).

This kind of behaviour is not what you would expect from someone who is intellectually honest. This is the behaviour an ideologue displays when they are attempting to keep their mental ideological armour intact. To complete the picture he’s also very rude when making these false accusations, yet you see him complain about how others characterize him in the comment section of the same blog post. Lets also not forget how he can respond to critics when he thinks he’s falsely accused (archived here).

What I just highlighted is a small part of all the mistakes Watts made in the blog post; there’s probably enough in there to write a whole blog post series. I also didn’t go into the conspiracy ideation Watts displayed about the American Meteorological Society survey. The whole article is a mess and at the very least he should have apologized for his false accusation.

Why should I take anything said by him serious with such a lack of intellectual honesty and civility?

Update 2013-11-22 @ 6:53:
It was pointed out to me that my reference to the WUWT blog post ‘Cook’s 97% climate consensus paper crumbles upon examination’ doesn’t accurately describe this blog post. Due to this it misrepresented what was said in it and because of that this blog post was updated. My apologies to Watts for this mistake.

The correction applies to the following original paragraph:

No, it doesn’t fall apart. What Watts is referring to is a letter he published on his blog written by Richard Tol. I already have a response to this letter on my website called ‘Cook’s 97% Climate Consensus Paper Doesn’t Crumble Upon Examination‘. Please read that for the full context, but I’ll lift the following relevant part from it

The paragraph now reads (changes are bolded):

No, it doesn’t fall apart. What Watts is referring to is a Facebook response from Bjørn Lomborg and a letter by Richard Tol he published on his blog. I already have a response to this blog post on my website called ‘Cook’s 97% Climate Consensus Paper Doesn’t Crumble Upon Examination‘. Please read that for the full context, but I’ll lift the following relevant part from it:

Also the quote my blog post ‘Cook’s 97% Climate Consensus Paper Doesn’t Crumble Upon Examination’ blog post was expanded to include two more paragraph so it reflects the above change.

Update 2014-02-23 @ 13:53:
Replaced my text about the percentages with the explanation from the survey.