A new paper by Dr. Richard Tol published today in ScienceDirect, journal of Energy Policy, shows that the Cook et al. paper claiming that there is a 97% consensus among scientists is not just impossible to reproduce (since Cook is withholding data) but a veritable statistical train wreck rife with bias, classification errors, poor data quality, and inconsistency in the ratings process. The full paper is available below.
Quantifying the consensus on anthropogenic global warming in the literature: A re-analysis
Richard S.J. Tol dx.doi.org/10.1016/j.enpol.2014.04.045
A claim has been that 97% of the scientific literature endorses anthropogenic climate change (Cook et al., 2013. Environ. Res. Lett. 8, 024024). This claim, frequently repeated in debates about climate policy, does not stand. A trend in composition is mistaken for a trend in endorsement. Reported results are inconsistent and biased. The sample is not representative and contains many irrelevant papers. Overall, data quality is low. Cook׳s validation test shows that the data are invalid. Data disclosure is incomplete so that key results cannot be reproduced or tested.
Conclusion and policy implications
The conclusions of Cook et al. are thus unfounded. There is no doubt in my mind that the literature on climate change overwhelmingly supports the hypothesis that climate change is caused by humans. I have very little reason to doubt that the consensus is indeed correct. Cook et al., however, failed to demonstrate this. Instead, they gave further cause to those who believe that climate researchers are secretive (as data were held back) and incompetent (as the analysis is flawed).
It will take decades or longer to reduce carbon dioxide emissions to zero—the only way to stabilize its atmospheric concentration. During that time, electoral fortunes will turn. Climate policy will not succeed unless it has broad societal support, at levels comparable to other public policies such as universal education or old-age support. Well-publicized but faulty analyses like the one by Cook et al. only help to further polarize the climate debate.
Full paper available in plain text here: http://www.sciencedirect.com/science/article/pii/S0301421514002821