Perspective: Climate crisisMillions of Times Later, 97 Percent Climate Consensus Still Faces Denial

In July, the Exxon- and Koch- funded Competitive Enterprise Institute (CEI) issued a formal complaint, asking NASA to “correct” a statement on the space agency’s website that said that “Multiple studies published in peer-reviewed scientific journals show that 97 percent or more of actively publishing climate scientists agree: Climate-warming trends over the past century are extremely likely due to human activities.”  In its complaint about NASA’s accurate statement, CEI cited 5-year-old disproved blog posts with titles like “1.6%, Not 97%, Agree that Humans are the Main Cause of Global Warming.”

So, what is the real percentage of climate researchers who agree that climate change is largely man-made? And what is the origin of the widely held perception among the American public that the science is still unsettled?

Dana Nuccitelli writes in the Bulletin of the Atomic Scientists that:

By coincidence, also in July, a 2013 paper that I co-authored with my colleagues at Skeptical Scienceon the expert consensus about human-caused climate change in peer-reviewed literature was downloaded for the millionth time. In that study, our team examined the abstracts of nearly 12,000 peer-reviewed climate science studies published between 1991 and 2011, and categorized each one based on its position on the causes of global warming. In a second phase of our analysis we e-mailed the authors of each study and asked them to categorize their own papers using the same criteria, receiving 1,200 responses. Our team’s review of the abstracts yielded a 97.1 percent consensus that humans are primarily responsible for recent global warming; the author self-ratings yielded a 97.2 percent consensus.

Their analysis built upon a previous study published by Naomi Oreskes in the peer-reviewed journal Science in 2004. In her paper, which also just surpassed 1 million downloads, Oreskes examined the abstracts of 928 peer-reviewed climate papers published between 1993 and 2003. In her review, none of the abstracts disputed human-caused global warming. Not a single one out of 928. “In 2016, our two groups teamed with the authors of five other climate consensus studies to publish a paper documenting the ‘consensus on consensus,’ in which we demonstrated that between 90 and 100 percent of climate scientists and their peer-reviewed research agree that humans are the main cause of recent global warming,” Nuccitelli writes.

That so-called “consensus gap” between public perception and the reality of expert agreement is largely due to a sustained misinformation campaign. “It is in the fossil fuel industry’s best short-term self-interest to spread doubt on this issue.,” Nuccitelli writes. “As our 97 percent consensus study lead author and cognitive scientist John Cook has documented, social science research shows that accepting the presence of expert climate consensus is a ‘Gateway Belief.’ This means that when people are aware of the consensus of the experts when it comes to climate change, they are more likely to accept the science and support climate policies that would reduce fossil fuel industry profitability.”