I've published two scientific papers measuring the scientific consensus on climate change. An analysis of climate papers found that among scientists publishing peer-reviewed climate papers, there was overwhelming scientific agreement that humans are causing global warming. A separate survey of scientists found that among scientists publishing peer-reviewed climate papers, there was overwhelming scientific agreement that humans are causing global warming.
Two scientific studies both finding a scientific consensus on climate change. Not that interesting, right? But wait, it gets even less interesting! We weren't the first scientists to find this result. In 2009, a survey of Earth scientists found that among climate scientists publishing climate research, 97% agreed that humans were causing global warming. In 2010, an analysis of public statements about climate change found that among scientists who had published climate research, 97% had endorsed the consensus.
When our paper finding 97% consensus was published in 2013, what surprised me was how surprised everyone else seemed to be. Newspapers published breaking news headlines. President Obama tweeted about the 97% consensus. Several times.
Equally surprising was Senator Rick Santorum recently trying to use our research that found an expert consensus to argue there wasn't an expert consensus.
How was Santorum able to take peer-reviewed scientific research and distort it beyond recognition? To understand how science can get distorted, you need to understand the techniques of science denial. These don't only apply to climate science denial. The same types of arguments are seen whether someone is denying the link between smoking and cancer, the scientific consensus about evolution or human-caused global warming. The five tell-tale techniques of science denial are Fake Experts, Logical Fallacies, Impossible Expectations, Cherry Picking and Conspiracy Theories. A useful way to remember them is the acronym FLICC:
Santorum's claim that our study found only 43% expert consensus originates from a blogger going by the pseudonym Fabius Maximus, who uses two denialist techniques: Fake Experts and Impossible Expectations.
Fake Experts are people who appear to be scientific experts but don't possess the actual relevant expertise. Santorum claims our survey was of 1800 climate scientists. This is not the case. We surveyed 1868 scientists but they weren't all climate scientists. We cast our net wide - in part because we wanted to obtain a diversity of viewpoints. To obtain the expert consensus, we looked to participants who had published over 10 peer-reviewed climate-related papers. Among these experts, we found 90% consensus (lead author Bart Verheggen explains in much greater detail).
Impossible Expectations involves raising the level of proof required to impossible levels. The tobacco industry perfected this strategy in the 1970s, demanding ever higher levels of proof that smoking causes cancer in order to delay regulation of their industry. In the case of Santorum's 43% consensus, this only included scientists at least 95% confident that humans were causing most of global warming. That means as far as Santorum was concerned, a scientist who was 90% confident that humans were causing most of global warming wasn't considered part of the consensus. If you raise the level of proof high enough, you can make the consensus simply disappear.
Unfortunately, Santorum misled the public by distorting scientific research, using misinformation from an anonymous blogger. It's especially ironic that he distorted one of my research papers to cast doubt on another of my research papers (quoting from a critic of our 97% consensus paper). I suspect that if Santorum were to learn that the 97% consensus had been replicated in three independent studies, he would be just as surprised as everyone else was when our 97% consensus paper was first published.