In the discussion over Michael Duffy’s SMH article, we had a lot of trouble with a survey supposedly showing that 25 per cent of climate scientists doubted the reality of anthropogenic (human-caused) climate change. We’ve tracked the survey downhere and it appears that the relevant question is number 40
Climate change is mostly the result of anthropogenic causes.
Respondents have to answer on a 7 point Likert scale from Strongly agree to Stongly disagree
Tim Lambert observes that this was an online survey, which may raise doubts about the sample frame, though it appears that Dennis Bray, who ran the survey, tried to keep participation limited to those in the study population.
Brian Bahnisch comments
To me the question is too open-ended. Surely any rational, logical scientist would see that â€œclimate changeâ€? has been going on a lot longer than we have been walking upright.
It is also possible to think that anthropogenic causes are less than natural ones, but still a significant, indeed critical, influence.
How does he count the fence-sitters who marked â€œ4â€??
and I share these concerns.
Anyway, the immediate problem is that Bray has set up some fancy code to display the survey results and neither Brian or I can make it work. It appears to be set for either Mozilla or Windows IE. Can anyone find the results and advise me.
Update Thanks to TIm Lambert, who has located what appear to be the results to Question 40 here The number giving “Disagree” responses (29 per cent) roughly matches the 25 per cent cited by Duffy, who was apparently relying on a second-hand and not very reliable source. But, as we’ve seen the description of the question given by Duffy was incorrect, as was the date of the survey and the description of the sample population, not to mention the characterisation of the thinktank where the results were presented.
There’s obviously a big difference between “the modest warming of the past 150 years is due to human activity” (Duffy’s description) and “Climate change is mostly the result of anthropogenic causes” (Bray’s actual question) and neither represents the IPCC position, which is that at least some of the warming observed over the last 50 years is anthropogenic and that, under current policies, this warming will continue. For appropriate time scales (say, as short as an El Nino cycle or longer than 1000 years) it seems pretty clear that natural causes are dominant, so it’s perfectly reasonable to disagree with, or give a “Can’t answer” response to Bray’s question, while agreeing with the IPCC view.