97.1%: What the Climate Consensus Number Actually Counts
October 27, 2026 · Frisian News
Photo: Wikimedia Commons
The famous 97% figure comes from a 2013 study of over 12,000 climate paper abstracts. It applies only to the roughly one-third of those abstracts that took a position on the cause of warming, not to all papers reviewed or to scientists as a group.
97.1 percent. That is the figure from Cook et al. (2013), published in Environmental Research Letters on May 15, 2013, and it became one of the most repeated statistics in climate policy debates. Politicians, journalists and campaign groups condensed it to "97% of scientists agree." The study itself counted something narrower.
The researchers, a team of 24 citizen-science volunteers at Skeptical Science, searched for the terms "global warming" and "global climate change" in peer-reviewed journals published between 1991 and 2011. That search returned more than 12,000 papers. The team then rated each paper's abstract to determine whether it endorsed, rejected, or expressed no position on human-caused global warming. They completed over 24,000 abstract ratings in total.
Most papers said nothing on the question. Roughly two-thirds of the 12,000-plus abstracts took no position on the cause of warming, according to the Cook et al. study. The authors gave a reason for this: scientists doing climate research already treat the human contribution as settled and rarely restate it in an abstract. That explanation may be correct. It is also a judgment the study makes on behalf of the silent majority of papers.
Of the papers that did take a position, just over 4,000 in total, 97.1% endorsed human-caused global warming. That is the 97. It does not describe 97% of all 12,000 papers reviewed, and it does not, on its face, count scientists. It counts a subset of abstracts.
The study included a second check. The researchers emailed more than 8,500 authors and asked them to rate their own papers. Of the 1,200 scientists who responded, those whose papers took a position endorsed the consensus at a rate of 97.2%. That is a meaningful independent confirmation, though the response rate was 14 percent and the researchers acknowledged that bounced emails made the true rate unclear.
The popular shorthand "97% of scientists agree" compresses three steps into one. It skips past the fact that the base is abstracts, not scientists; that most abstracts were silent on causation; and that the 97 applies only to the roughly one-third that spoke. A poll cited in the study, from the Pew Research Center in 2012, found that less than half of Americans believed scientists agreed that humans were causing global warming. The consensus communication campaign set out to close that gap. The slogan was a tool for that campaign.
None of this means the underlying agreement is invented. Among papers that did state a position, in both the team's ratings and the authors' own self-ratings, the figure lands at 97 percent. A separate survey by Doran and Zimmerman in 2009, cited in Cook et al., found that 75 of 77 actively publishing climatologists, or 97.4%, agreed that human activity is a significant contributing factor in changing mean global temperatures. Anderegg et al. (2010), also cited in Cook et al., found approximately 97% agreement among self-identified actively publishing climate scientists, drawn from a compiled list of 908 researchers with at least 20 peer-reviewed climate publications.
The number is real. The label on the number is not.
Published October 27, 2026 · Frisian News