Two years ago, a group of international researchers led by University of Queensland's John Cook surveyed 12,000 abstracts of peer-reviewed papers on climate change since the 1990s. Out of the 4,000 papers that took a position one way or another on the causes of global warming, 97 percent of them were in agreement: Humans are the primary cause. By putting a number on the scientific consensus, the study provided everyone from President Barack Obama to comedian John Oliver with a tidy talking point.

That talking point put climate deniers in a bind. They have successfully delayed political action for years by making it seem like there's still a scientific debate over anthropogenic warming. But when confronted with a statistic like this one, they have been forced to take a different tack: dispute the statistic itself.

They're the 97 percent truthers, and Texas Senator Ted Cruz is leading the recent charge. At a hearing in early October, the GOP presidential candidate peppered Sierra Club President Aaron Mair with questions for ten minutes about the so-called 18-year pause in global warming—a point that's been thoroughly debunked. Mair replied to Cruz’s repeated demands to retract his testimony on climate change by citing the 97 percent consensus, which Cruz brushed off by saying the “problem with that statistic that gets cited a lot is it’s based on one bogus study.” Cruz added that the point was irrelevant to the debate. “Your answer was, pay no attention to your lying eyes and the numbers that the satellites show and instead listen to the scientists who are receiving massive grants who tell us do not debate the science,” he said.

Conservative sites celebrated Cruz's questioning. National Review ran two stories, one claiming “Ninety-seven percent of the world’s scientists’ say no such thing” and another that “the 97 percent stat is pure public relations b.s.” The attempts to discredit Cook's study are as old as the study itself. Rick Santorum, another Republican presidential candidate, contested the 97 percent consensus in late August. "That number was pulled out of thin air,” he told Bill Maher. The Wall Street Journal took issue with it last year, arguing that these peer-reviewed studies never said manmade climate change was “dangerous.”

The main criticism of Cook's study is that it omits the vast number of papers that take no position on global warming's causes. That's true: Cook’s study of the 12,000 abstracts found that 66 percent of them took no position, so he excluded them in calculating the percentage. As Cook explained in an online video, he omitted these papers because abstracts are short summaries that "don’t waste time stating something they assume their readers will already know"; just as most "astronomy papers don’t think it necessary to explain that the Earth revolves around the sun," he said, "nowadays most climatology papers don’t see the need to reaffirm the consensus position.”