A paper published this week (or more accurately a press release that accompanied it) seemed to suggest that 97.5% of all climate scientists who have published papers over the last decade (some 11,944 papers) agree that humans are the primary cause of climate change. The implication was that the science is settled. Even President Obama tweeted his “blessing” of this conclusion.
But things are not as they seem. First, 66% of all of the papers reviewed took no position whatsoever with respect to anthropocentric explanations of climate change – only 32.6 of the papers supported the general idea that humans cause climate change. That is 3,893 papers. For 0.7% of the papers, the human explanation was rejected and for a further 0.3% the suggestion was that the climate system is so complex we do not yet fully understand it.
But if we apply the criteria, suggested by the authors of the paper, that humans must be the dominant cause of climate change for the reported claim to be true, we have a real problem. This occurs in just 65 of the papers. Do the math. That is 0.5% of the papers support the contention that humans are the primary cause of climate change. Put this another way, more of the papers reject this explanation (75 papers or 0.6%) than support the strong hypothesis of humans being the dominant factor in climate change. You can read a detailed analysis of the data base here.
The worrying issue here is about our understanding of the nature of the scientific endeavor. If science was about consensus, then we would all be in trouble. It is not, it is about evidence, understanding and confirmation through theory and verification. The kind of paper that needs to exaggerate (being generous) so as to make a point stands in the face of scientific inquiry and is unbecoming.
Now lets get back to the practice of normal science.