A new paper by Skeptical Science bloggers claims to chart depth of global warming consensus since 1991. Here's my email back and forth with John Cook, Dana Nuccitelli et al. Here's the link to the paper: http://iopscience.iop.org/1748-9326/8/2/024024/article

1. New paper finding 97% AGW consensus
7 messages
Dana Nuccitelli Mon, May 13, 2013 at 10:48 AM
Reply-To: Dana Nuccitelli
Hi Justin and Andy. You may have already received the press release about our
forthcoming paper, but I thought it might be useful to provide some more
detail. About a year and a half ago, a team of about two dozen Skeptical Science
volunteers began this project to quantify the consensus on human-caused global
warming in the peer-reviewed scientific literature. It's basically an expansion on the
results of Oreskes (2004), but much larger – the most comprehensive survey of its
kind. In addition to rating over 12,000 abstracts, we also contacted the authors of
the studies we surveyed and received over 2,000 self-ratings from 1,200
scientists. In both independent methods, among the papers taking a position on the
cause of global warming, 97% agreed that humans are causing it. Our 'rejections'
category also included papers that minimized the human influence; for example, a
paper saying that most global warming has been caused by the sun fell into the 2–
3% 'rejections' category, even if it said that some warming is anthropogenic.
The reason our paper is particularly important is because research has shown there's
a strong correlation between public awareness of the consensus and support for
climate mitigation. However, the public is very misinformed on the issue, with the
average American believing that scientists are split 50/50 on the cause of global
warming. So it's critical that we close this consensus gap. Thus we're hoping for a
lot of media coverage of our paper and results.
For further details, you can see my embargoed SkS blog post on the paper. I've also
attached embargoed copies of the paper and press release. The embargo lifts
midnight GMT Thursday (May 16th).
There are a couple other interesting aspects about the paper. We're setting up a
system at SkS where anybody can go review and rate the same abstracts as in our
survey to test our results for themselves (not active yet, but will be located here). A
New York-based marketing company, SJI Associates also created a website based
around our results pro-bono, TheConsensusProject.com, including some really nice
graphics that can be shared via social media. If you'd like to see the SJI page, the
username is 'secure' and the password is '97percent'. Everything will launch on
Thursday. Our paper is also open access, free for anyone to download. The fee to
make that happen was paid with donations from Skeptical Science readers (raised in
under 10 hours).
Please let me know if you have any questions. Thanks.
-Dana Nuccitelli

2. Skeptical Science
The Guardian
Andrew Revkin <> Mon, May 13, 2013 at 2:20 PM
To: Dana Nuccitelli< John Cook
The abstract is a bit dizzying...
1) why go as far back as 1991? completely complicates the data because from then til 2001
IPCC report, if you were saying humans are causing global warming you would have been
outside the consensus?
2) so 97.1 percent of 32.6 percent say warming is human caused? 66 percent take no
position.. and this means...??
3) why not put this through peer review at one of the many journals, like Climatic Change,
that focus on this kind of question?
all of what's laid out above almost guarantees you'll end up muddying waters more than
clarifying things when this comes out, unless i'm missing something. (happy for any clarity)
[Quoted text hidden]
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Dana Nuccitelli <> Mon, May 13, 2013 at 2:54 PM
Reply-To: Dana Nuccitelli<
John Cook
Hi Andy. Here are some responses to your questions:
1) Oreskes' survey covered 1993 through 2003. We wanted to include the same
dates to verify her results, and extend beyond them. I believe we chose 1991 as the
start date to make the survey encompass an even two decades, but I could be mis-
remembering (John would probably know offhand).
We didn't pre-define the 'consensus'. The survey was simply about the papers'
positions on the cause of global warming. As it turns out, at least 90% of papers
taking a position on the issue agreed that humans were the cause in every year
1991–2011, based on our abstract ratings (there was a bit more noise in the author
self-ratings due to the smaller sample size, but I believe there was at least 80%
agreement even in the early 1990s in the self-ratings). So the 'consensus' was a
result of our survey, having already been well-established by 1991. We have
a figure in our paper showing the consensus evolution over time.

3. 2) 'No position' just means they didn't say anything about the cause of global
warming in the abstract. In the author self-ratings, which were based on the full
paper, nearly two-thirds did take a position, with the same 97% agreeing on the
human cause. Oreskes in 2007 predicted that fewer papers would talk about the
cause of global warming as the consensus became more widely-accepted. There's
just no reason to continue to state something everybody accepts, especially in the
abstract where words are at a premium (we discuss this in the paper).
This is why we specify the 97% consensus is for papers that take a position on the
cause of global warming. There are a lot of papers which investigate some aspect of
the climate system that don't take a position on its cause, either because they feel it
doesn't need to be said or because they just didn't address the cause. We were also
very conservative on this. For example, you could easily argue that a paper
assuming continued global warming accepts the human cause, because why else
would you expect global warming to continue? However, unless they somehow
linked the warming to human greenhouse gas emissions, we didn't rate it as an
'endorsement', we put it in 'no opinion', even if it assumed indefinitely continued
warming.
3) We chose ERL because it's a high-impact journal with an open access option (I'm
not sure offhand if Climatic Change has that option, but it was one of our main
considerations), and our paper seemed to fit within their scope.
-Dana Nuccitelli
John Cook <> Mon, May 13, 2013 at 5:19 PM
To: Dana Nuccitelli
Hi Andy, Dana, Justin,
Just adding to Dana's first answer. Obviously, our intent was to analyse a much larger
sample of papers which is why we added an extra decade to the time period of Oreskes'
analysis and also included "global warming" papers (Oreskes' search was just for "global
climate change" papers). The reason we specifically started in 1991 was because the Web
of Science added abstracts to their database to papers going back to 1991. At the time of
the Oreskes' 2004 analysis, the Web of Science database had abstracts only going back to
1993.
Regards
John
[Quoted text hidden]
Andrew Revkin > Mon, May 13, 2013 at 5:22 PM
To: John Cook
Cc: Dana Nuccitelli

4. Still feels pretty useless (meaning the same goes for Naomi's paper) given that anything
stating warming (post 1950 or...) was human caused before 2001 (TAR) did not comport
with any consensus at the time.
[Quoted text hidden]
John Cook <> Mon, May 13, 2013 at 5:30 PM
To: Andrew Revkin >
Cc: Dana Nuccitelli
The fact that the peer-reviewed literature was already showing overwhelming agreement on
human-caused global warming demonstrates in a quantitative fashion that there *was* a
consensus prior to TAR. The IPCC didn't originate the consensus - it formalised the pre-
existing consensus in a synthesising report. This is actually an important result - it shows
that the consensus wasn't manufactured by the IPCC but spontaneously emerged in the
peer-reviewed literature.
[Quoted text hidden]
Andrew Revkin <> Thu, May 16, 2013 at 11:30 AM
To: John Cook <>
Cc: Dana Nuccitelli<
still swamped and not writing on this but a final reply to john's note about the
findings showing that the consensus emerged in the literature....
how do you show (in sci parlance) that the lack of mention of the
Anthropogenic element in global warming in > 60 percent of papers means
those authors all accept that AGW is evident?