Abstract
We analyze the evolution of the scientific consensus on anthropogenic
global warming (AGW) in the peer-reviewed scientific literature, examining
11 944 climate abstracts from 1991–2011 matching the topics 'global climate
change' or 'global warming'. We find that 66.4% of abstracts expressed no
position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain
about the cause of global warming. Among abstracts expressing a position on
AGW, 97.1% endorsed the consensus position that humans are causing global
warming. In a second phase of this study, we invited authors to rate their own
papers. Compared to abstract ratings, a smaller percentage of self-rated papers
expressed no position on AGW (35.5%). Among self-rated papers expressing a
position on AGW, 97.2% endorsed the consensus. For both abstract ratings and
authors' self-ratings, the percentage of endorsements among papers expressing a
position on AGW marginally increased over time. Our analysis indicates that the
number of papers rejecting the consensus on AGW is a vanishingly small
proportion of the published research.