Consensus on consensus: Expertise matters in agreement over human-caused climate change

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A research team confirms that 97 percent of climate scientists agree that climate change is caused by humans. The group includes Sarah Green, a chemistry professor at Michigan Technological University.

"What's important is that this is not just one study—it's the consensus of multiple studies," Green says. This consistency across studies contrasts with the language used by climate change doubters. This perspective stems from, as the authors write, "conflating the opinions of non-experts with experts and assuming that lack of affirmation equals dissent."

Environmental Research Letters published the paper this week. In it, the team lays out what they call "consensus on consensus" and draws from seven independent consensus studies by the co-authors. This includes a study from 2013, in which the researchers surveyed more than 11,000 abstracts and found most scientists agree that humans are causing climate change. Through this new collaboration, multiple consensus researchers—and their data gathered from different approaches—lead to essentially the same conclusion.

The key factor comes down to expertise: The more expertise in climate science the scientists have, the more they agree on human-caused climate change.