This forum is about wrong numbers in science, politics and the media. It respects good science and good English.
I suppose it's worth updating this old thread as there was a major development in the 97% consensus saga last month, with the publication of a completely new study which derives the magic 97% number again.
This study was produced by John Cook, who runs the misleadingly named Skeptical Science blog, along with eight co-authors from four English-speaking countries. A free to view copy of the paper "Quantifying the consensus on anthropogenic global warming in the scientific literature"
is available on this link:
We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11,944 climate abstracts from 1991–2011 matching the topics 'global climate change' or 'global warming'. We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming. In a second phase of this study, we invited authors to rate their own papers. Compared to abstract ratings, a smaller percentage of self-rated papers expressed no position on AGW (35.5%). Among self-rated papers expressing a position on AGW, 97.2% endorsed the consensus. For both abstract ratings and authors' self-ratings, the percentage of endorsements among papers expressing a position on AGW marginally increased over time. Our analysis indicates that the number of papers rejecting the consensus on AGW is a vanishingly small proportion of the published research."
It looks like the major difference between this paper and the two previous studies which came up with the 97% figure is that in this latest study the 97% figure relates to those climate scientists who actually expressed an opinion on AGW. Two thirds of the nearly 12000 papers whose abstracts were reviewed were regarded as having taken no position on AGW. I suppose this is an improvement on the study by Oreskes in 2004 (extensively quoted by Al Gore) which also looked at abstracts for papers in the climate science literature and came up with the highly implausible consensus figure of 100%.
My observation earlier in the thread that the 97% figure is "the Green equivalent of 8 out of 10 cats" is even more pertinent following the Cook study. For people not familiar with the "8 out of 10 cats" phrase, which is also the name of a TV comedy panel show on topical news and opinion polls in the UK, it was originally used in a TV advertising campaign by the makers of a cat food called "Whiskas". The advertising slogan in the 1960s was "eight out of ten owners said their cat prefers it", but by the 1980s advertising regulators had forced them to modify it to "eight out of ten owners who expressed a preference said their cat prefers it".
There was a warning last year in 2012 that this Cook study would be coming along, after a hacker/leaker released details about something called "The Consensus Project" that was being discussed in a private forum connected with Cook's Skeptical Science blog.
In addition to carrying out the study the discussions were making a big thing of the idea of 'marketing' the study. One manifestation of this marketing may be that a new blog that has been set up in the Guardian's environment section called "Climate Consensus - The 97%" run by John Abraham and Dana Nuccitelli (Nuccitelli is one of the co-authors of the new paper). This new blog seems to have taken over from Damian Carrington as the spearhead of the Guardian's commentary on AGW.
There has been some criticism of the new study, for example this article from WUWT where some AGW sceptic scientists have complained that their papers were incorrectly classified:
96.7% of all statistics are made up. And that's a fact.