Klimaat: consensus?
Dat laatste lijkt inderdaad het geval te zijn. Maar de uitkomsten van dat onderzoek blijken nogal creatief te zijn geïnterpreteerd, om het maar mild uit te drukken. In dat onderzoek is overigens geen sprake van 99% maar 97%. Maar een kniesoor die daarop let.
to assess the scientific consensus on climate change through an unbiased survey of a large and broad group of Earth scientists.
1. When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?
2. Do you think human activity is a significant contributing factor in changing mean global temperatures?
A new poll among 3,146 earth scientists found that 90 percent believe global warming is real, while 82 percent agree that human activity been a significant factor in changing mean global temperatures.
The survey, conducted among researchers listed in the American Geological Institute's Directory of Geoscience Departments, "found that climatologists who are active in research showed the strongest consensus on the causes of global warming, with 97 percent agreeing humans play a role.
The paper is behind a pay wall but there is a comprehensive summary here.
We find that they originally contacted 10,257 scientists, of whom 3,146 responded, less than a 31% response rate. Impending Planetary Doom was obviously not uppermost in the minds of over two thirds of their target population. Of that number, only 5% described themselves as climate scientists, numbering 157. The authors reduce that by half by only counting those who they classed as specialists.
In our survey, the most specialized and knowledgeable respondents (with regard to climate change) are those 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 (79 individuals in total). Of these specialists, 96.2% (76 of 79) answered risen to question 1 and 97.4% (75 of 77) answered yes to question 2.
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The phrase 97 percent of the world's climate scientists sounds very dramatic and over-whelming, but the truth is somewhat different. . The response figure of 3,146 is the figure against which the 75 out of 77 should be compared and in this case we get not 97% but just 2.38%.
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