The claim goes something like this: “97 percent of climate scientists agree with climate change.” This assertion has been used by politicians and celebrities alike to promote and justify government ‘solutions’ to the imminent global crisis.
This claim to 97 percent of scientists is rooted in a 2013 paper authored by John Cook, of the Global Change Institute at the University of Queensland, Australia. Cook’s summary of his paper indicates that it had “found that over 97 percent [of papers reviewed] endorsed the view that the Earth is warming up and human emissions of greenhouse gases are the main cause.”
That summary is deceptive. In fact, over two-thirds of the papers surveyed expressed no position at all on human-caused global warming. The 97 percent that agreed with the human cause of global warming came from the other one third. Get that? 97 percent of one third. Which is, well, less than a third, isn’t it? Hardly the ‘almost all’ implied by ’97 percent’!
Further, a public challenge of Cook’s paper turned up the fact that less than two percent of the papers reviewed explicitly stated that man-made greenhouse gases were the main cause – causing at least 50 percent – of global warming.
Cook also created special categories for papers which did not agree explicitly. For papers which did not state how much of the warming was caused by humans – whether one percent, 50 percent or 100 percent – and for papers which only implied some man-made global warming (but did not state it directly), Cook created classifications he labeled as endorsing the hypothesis.
After publication of Cook’s paper, several of the scientists whose papers were reviewed and classified for the survey were compelled to speak out. Almost two thirds of these disagreed with Cook about the message of their own papers.
Responses included, ‘That is not an accurate representation of my paper,’ ‘the analysis itself is faulty,’ ‘certainly not correct and certainly misleading,’ ‘[Cook’s] is not the study to read if you want to find out about what we say and conclude in our own scientific works,’ and ‘nothing could be further from either my intent or the contents of my paper.’
Richard Tol, professor of economics at the University of Sussex, was one of the scientists whose work was reviewed in the Cook survey. Tol has been outspoken in his criticism of the Cook paper and the methodology used by the authors.
In The Guardian, Tol wrote, “Most of the papers they studied are not about climate change and its causes, but many were taken as evidence nonetheless. Papers on carbon taxes naturally assume that carbon dioxide emissions cause global warming – but assumptions are not conclusions.”
So there’s the lie: that there is a consensus in such a majority. Not that there’s anything wrong with a consensus among scientists. One can only imagine the tension in the scientific community when there was no settled consensus regarding the flatness or roundness of the earth. Or can one?
In truth, most of the scientific community probably is in agreement regarding many of the issues involved. The effects of atmospheric carbon dioxide on temperature, for example, is pretty much settled. And there’s little doubt that humans have contributed to the release of carbon dioxide into the atmosphere.
It gets murkier when you start looking into the big picture, long-term projections and computer models. There is a great deal of conflicting information on the issue, and plenty to choose from when someone with an agenda wants to go cherry-picking.
Using junk science, deceptive data, and propaganda pieces to gain leverage for legislation only bolsters the case of climate change deniers. It also undermines efforts to change our ways now for the sake of future outcomes, as well as wasting resources that could be put to better use in finding real solutions.
It’s important to listen to all sides, and it’s also helpful to learn to listen critically, to push and probe and ask questions. Liberally apply some common sense to an open mind. The beauty of science is that skepticism is built right in, and there’s no such thing as a final answer.
Whatever we think we know, the one thing you can know for sure is that there will always be more to learn beyond that. Remember when everyone believed the earth was flat? No? Well, that’s because a few nuts with an unpopular opinion refused to back down from the ‘consensus.’