I shall bookmark this and wheel it out every time some muppet yells consensus. 
Michael Crichton said: “If it’s consensus, it isn’t science. If it’s  science, it isn’t consensus.” Thales of Miletus, Abu Ali Ibn al Haytham,  Newton, Einstein, Popper and Feynman thought much the same and said so.  Science by head-count is mere politics.
 Doran and Zimmerman (2009) and Anderegg 
et al. (2010) each  concluded that 97% of a few dozen carefully-filtered climate scientists  held Man guilty of some of the 0.7 Cº global warming since 1950.
 Cook 
et al. (2013), in a recent me-too article in 
Environment Research Letters,  conducted the largest-ever sensational epic blockbuster  cast-of-thousands drama survey of scientific papers on climate change.  They concluded that 97.1% of abstracts expressing an opinion on climate  change endorsed the “scientific consensus”.
 Here’s how they did it.
 They examined 11,944 abstracts. But they arbitrarily threw out almost  8000 of them on the ground that they had not toed the Party Line by  expressing the politically-correct opinion (or any opinion) on climate  change.
 Next, they ingeniously interchanged three separate versions of the imagined “scientific consensus”: that Man had caused 
some warming; that Man had caused 
most of  the warming since 1950; and that man-made warming would be catastrophic  unless the West were shut down and climate sceptics were put on trial –  as the appalling James Hansen has suggested – for high crimes against  humanity.
 It was this last definition – in fact untested in Cook 
et al. or,  as far as I know, in any other paper – that Mr Obama’s Twitteratus  plumped for when he tweeted that 97% of scientists consider climate  change not only real but “dangerous”.
 The introduction to the Cook paper said that the survey was intended  to examine the standard or IPCC “scientific consensus” that most of the  warmer weather since 1950 was our fault.
 The authors, having consigned 7930 abstracts to the Memory Hole  because they had not parroted the Party Line, were left with 4014  abstracts. They marked just 64 of them, or 1.6% of the 4014 abstracts,  as endorsing the standard version of “scientific consensus”.
 Further examination by Legates 
et al. (2013) showed that  only 41 of the 64 abstracts, or 1.0% of the 4014 abstracts expressing an  opinion on the Party Line, or just 0.3% of the original 11,944  abstracts, had said Yes to the standard version of consensus.
  
 
The incredible shrinking consensus
 
(A) Cook 
et al. claimed  97.1% consensus among 4014 abstracts; but (B) that was only 32.6% of  all 11,944 abstracts in their sample; and (C) only 1% of the 4014 papers  or (D) 0.3% of the entire 11,944 sample actually said Yes to the  “scientific consensus” as Cook 
et al. had defined it.
 However, since 32.6% of all 11,944 abstracts, or 97.1% of the 4010  abstracts expressing an opinion on the Party Line, had said or implied  that Man causes 
some warming, Cook 
et al. concluded by saying that 97.1% of all abstracts expressing an opinion had said that Man had caused 
most of the warming since 1950.
 The totalitarian news media (that is just about all of them), ever  careless with their logical quantifiers, dutifully reported that 97.1%  of 
all scientists had stated their support for the “scientific consensus” that 
all global warming since 1950 was manmade.
 The website of the Institute of Physics reported one of Cook’s  co-authors as saying that the paper had indeed concluded that there was  97.1% support for that notion.
 
However, in my submission it is time for sceptics not merely  to express dismay at the flagrant distortion of the objective truth that  has occurred. I reported that co-author to his university for  misconduct in the dissemination of research results, and the university  has told me it has decided to investigate.
 The Institute of Physics, to whom I also complained, says it does not  propose to alter its story because, it says, the co-author’s statement  accurately reflects the paper’s conclusion. I have sent it the authors’  own data-file and have asked it to check that the authors themselves had  marked only 64 out of 11,944 papers as endorsing the version of  “scientific consensus” for which the paper claims 97.1% consensus.
 I have asked that the Institute should at least report that the  result of the paper has been credibly challenged in the peer-reviewed  literature; and I await its reply.
 A report of research misconduct has gone to the Vice-Chancellor of  Queensland University and to the Professor who is the “designated  person” to investigate the lead author under the University’s research  policies. I await a reply from either of them.
 This is where you come in, gentle readers. For I have written a letter to the editor of 
Environmental Research Letters asking him to withdraw the paper on the ground that it is not merely defective but deceptive. The letter is below.
 I should be very grateful if every reader who agrees with me that the  paper should be withdrawn would send a message to this thread giving  their names and, if they wish, their academic qualifications. I shall  then add the names to the letter and send it to the editor. Jo Nova  herself is a signatory. Please join us.
 The paper should have been withdrawn long ago, but it is perhaps not  unreasonable to suspect that the board of the journal, whose members  include Peter Gleick, will delay doing the inevitable for as long as  possible in the hope of not undermining the IPCC’s arbitrary decision,  in its imminent 
Fifth Assessment Report to assign a 95% confidence interval to the proposition that we caused most of the warming since 1950.
 On the evidence that Cook 
et al. have themselves collected,  there is no legitimate scientific basis whatsoever for any such  confidence interval. Like much else in the IPCC’s disgraceful documents,  it is simply made up.
 There was a sting in the tail of my latest reminder note to the editor of 
Environment Research Letters. I said that I hoped I should not have to involve the public authorities.
 For the most disturbing aspect of this affair is that the result that  the paper claims is egregiously at variance with the authors’ own  categorization of the 11,944 abstracts in their own data-file.
 Yet the authors themselves, though they have read Legates 
et al., have not withdrawn their paper; aside from the editor of 
Environment Research Letters, not  a single member of the board has written back to me; the Institute of  Physics seems unbecomingly reluctant to correct its gravely misleading  story even though I have sent it Cook’s data-file and a copy of Legates 
et al. and  have asked it to verify the position for itself; and, after a longer  period than is reasonable in the circumstances, not one but two senior  officers of Cook’s university have failed even to acknowledge a  reasonable request that they should investigate.
 Something does not smell right. Should we be angry?
http://joannenova.com.au/2013/09/monckton-honey-i-shrunk-the-consensus/