Doran and Kendall Zimmerman, 2009
A poll performed by Peter Doran and Maggie Kendall Zimmerman at Earth and Environmental Sciences, University of Illinois at Chicago received replies from 3,146 of the 10,257 polled Earth scientists. Results were analyzed globally and by specialization. 76 out of 79 climatologists who "listed climate science as their area of expertise and who also have published more than 50% of their recent peer-reviewed papers on the subject of climate change" believe that mean global temperatures have risen compared to pre-1800s levels, and 75 out of 77 believe that human activity is a significant factor in changing mean global temperatures. Among all respondents, 90% agreed that temperatures have risen compared to pre-1800 levels, and 82% agreed that humans significantly influence the global temperature. Economic geologists and meteorologists were among the biggest doubters, with only 47 percent and 64 percent, respectively, believing in significant human involvement. A summary from the survey states that:
It seems that the debate on the authenticity of global warming and the role played by human activity is largely nonexistent among those who understand the nuances and scientific basis of long-term climate processes.[82]
[edit] Bray and von Storch, 2008
Dennis Bray and Hans von Storch conducted a survey in August 2008 of 2058 climate scientists from 34 different countries.[83]. A web link with a unique identifier was given to each respondent to eliminate multiple responses. A total of 373 responses were received giving an overall response rate of 18.2%. No paper on climate change consensus based on this survey has been published yet (February 2010), but one on another subject has been published based on the survey.[84]
The survey was composed of 76 questions split into a number of sections. There were sections on the demographics of the respondents, their assessment of the state of climate science, how good the science is, climate change impacts, adaptation and mitigation, their opinion of the IPCC, and how well climate science was being communicated to the public. Most of the answers were on a scale from 1 to 7 from 'not at all' to 'very much'.
In the section on climate change impacts questions 20, 21 were relevant to scientific opinion on climate change. Question 20 "How convinced are you that climate change, whether natural or anthropogenic, is occurring now?" got 67.1% very much agree, 26.7% to some large extent (5–6), 6.2% said to some small extent (2–4), none said not at all. Question 21 "How convinced are you that most of recent or near future climate change is, or will be, a result of anthropogenic causes?" received 34.6% very much agree, 48.9% agreeing to a large extent (5–6), 15.1% to a small extent (2–4), and 1.35% not agreeing at all.
[edit] STATS, 2007
In 2007, Harris Interactive surveyed 489 randomly selected members of either the American Meteorological Society or the American Geophysical Union for the Statistical Assessment Service (STATS) at George Mason University. The survey found 97% agreed that global temperatures have increased during the past 100 years; 84% say they personally believe human-induced warming is occurring, and 74% agree that “currently available scientific evidence” substantiates its occurrence. Only 5% believe that that human activity does not contribute to greenhouse warming; and 84% believe global climate change poses a moderate to very great danger.[85] [86]
[edit] Oreskes, 2004
A 2004 article by geologist and historian of science Naomi Oreskes summarized a study of the scientific literature on climate change.[87] The essay concluded that there is a scientific consensus on the reality of anthropogenic climate change. The author analyzed 928 abstracts of papers from refereed scientific journals between 1993 and 2003, listed with the keywords "global climate change". Oreskes divided the abstracts into six categories: explicit endorsement of the consensus position, evaluation of impacts, mitigation proposals, methods, paleoclimate analysis, and rejection of the consensus position. 75% of the abstracts were placed in the first three categories, thus either explicitly or implicitly accepting the consensus view; 25% dealt with methods or paleoclimate, thus taking no position on current anthropogenic climate change; none of the abstracts disagreed with the consensus position, which the author found to be "remarkable". According to the report, "authors evaluating impacts, developing methods, or studying paleoclimatic change might believe that current climate change is natural. However, none of these papers argued that point."