Teach Them about this Deeply Deceptive Statistic used by CAGW Spinners: the '97%'

The notorious, the fatuous, the misleading claim that  '97% of climatologists' believe in ('catastrophic' implied/stated/assumed) anthropogenic global warming has been rebutted many times.  Anyone with an elementary grasp of sample-survey techniques would have refused to publish the results, based as they are on a sloppy question, an imperfect frame, and a tiny subset of self-selected respondents of unknown qualifications.  But perhaps when you are saving the planet, the means justifies the ends, or more clearly, 'let's not let scientific integrity get in the way of political impact.'

The WUWT site has a post dated 4th March from Jospeh D'Aleo, a meteorologist, reacting to another meteorologist still trotting out that egregious 97% as if it were a clincher instead of an embarassment, as per:

'Of the climatologists, a staggering 97% agreed to the same question… It’s very difficult for me to understand the disdain for science that exists today.'  

Oh the ironing!  (as they say on the Daily Bayonet)

D'Aleo digs out an IceCap post from last December by Solomon, of the Canadian National Post, and reproduces part of it.  Here is an extract, referring to a crude online survey sent to 10,257 'Earth scientists', of whom only 3,146 chose to respond, and of them a subset of 77 was extracted to create the 97%:

'This number will prove a new embarrassment to the pundits and press who use it. The number stems from a 2009 online survey of 10,257 earth scientists, conducted by two researchers at the University of Illinois. The survey results must have deeply disappointed the researchers - in the end, they chose to highlight the views of a subgroup of just 77 scientists, 75 of whom thought humans contributed to climate change.  The ratio 75/77 produces the 97% figure that pundits now tout.'

Of course, with a mass media largely supine and uncritical under the whirling deluge of alarmist press releases, soundbites, and sundry spins, the '97%' grew wings and became something with which to impress the public.  But the public is catching up.  Teachers can contribute by ensuring that their pupils see that '97% ' as well-worthy of their disdain.

An SPPI report on the '97%' is available here: http://scienceandpublicpolicy.org/images/stories/papers/originals/consensus_opiate.pdf


Hat-tip: The Climate Science blog.

Added 7 March: There is analysis at Climate Quotes of the two questions used in the survey, noting that they could readily be answered in the affirmative by those who do not see any convincing evidence or arguments that AGW is a major and urgent threat: http://climatequotes.com/2011/02/10/study-claiming-97-of-climate-scientists-agree-is-flawed/

Added 19 July 2012.  Barry Woods provides a lot more information and insight into fatuous 97% and 98% claims: http://wattsupwiththat.com/2012/07/18/what-else-did-the-97-of-scientists-say/#more-60090
Amongst other things, he tracked down an MSc thesis that was the source of one of the most widely quoted 97% figures: 'As this MSc thesis was the original source of the oft cited Doran paper  97%  quote, I tracked it down (sometime ago now) and discovered in the appendi that there was a great deal of  email feedback and answers to write in questions from the scientists that actually participated in the survey, much of it critical and sceptical of the survey itself, the methodology and the questions asked. Additionally, amongst those environmental scientists that responded, were some very sceptical sounding scientists with respect to man made climate change being the dominant driver of climate change.'  
As well as the Doran/Zimmerman survey, he reports on the later Anderegg 'survey', and notes scathing critiques of it:
'Paul Matthews: “Scott Denning needs to be more careful if he and his fellow climate scientists are to be taken seriously by scientists from other fields such as myself. 
He loses credibility by referring to the ridiculous Anderegg et al study, in which the authors put scientists into two different pigeon-holes. '