Comparison of my results with those of Cook et al.
I found that 0.02% of articles (as opposed to authors) in 2013 and 2014 explicitly reject AGW; in their survey, Cook et al. found 0.2%. The difference is not due to differing standards for recognizing rejection. Using the same period (1991-2011) as Cook et al. and the same keywords of “global climate change” and “global warming,” in an unpublished study done before Cook et al. published, I identified 23 abstracts that explicitly reject AGW. Cook et al. found 24. The two lists are not identical, but show considerable overlap. Different reviewers thus reach the same conclusion: that the number of peer-reviewed articles that reject AGW is very small.
Instead the reason for the difference is that my survey covered two recent years, while that of Cook et al. went back to 1991. Over the 25 years from then until now, the number of rejecting articles has remained small and insignificant, while the total number of articles on global warming and climate change has risen enormously. In addition, I included “climate change” as a search term, which Cook et al. did not. That added thousands of articles but less than one handful of additional rejections. Here are the data:
The number of rejecting articles from 1991 through 2014 using “global warming” and “global climate change” (and including one article that I found from 2012) varied between 0 and 4 per year and averaged about 1.2. In 1991, there were 132 articles on “global warming” and 227 on “climate change.” In 2014, these had risen to 1,786 and 12,097, respectively.
Why has the number of articles on global warming and climate change grown so greatly? Because scientists have found it an important and fecund topic, with widespread application in a variety of disciplines. As evidence, those 1,786 articles on “global warming” in 2014 have to date led to 7,215 citations (excluding self-citations). In contrast, the rejecting articles have seldom been cited and some have never been. This can only mean that the rejecting articles have presented no evidence persuasive enough to attract the interest of other scientists, not even other global warming “skeptics.” In other words, the rejection of AGW has turned out to be a scientific and humanitarian dead end.