At least 90 percent of climate scientists agree the world is warming and it is largely our fault. The finding isn't news to anyone who is closely following the climate debate. However, with most non-scientists unaware of how overwhelming the agreement is, confirmation matters. A new paper, by a number of peer-reviewed published climate scientists who have come together to create a "consensus on consensus," provides this with unprecedented rigor.
However, people who are aware of the scientific consensus on this topic are mostly inclined to go along with what the people who do the research conclude. Most disagreement comes from people who think scientists are divided on the topic, a perception fueled by reports that give equal airtime to the occasional maverick as to dozens of scientists who are of similar mind.
Consequently, when John Cook of the University of Queensland found 97.1 percent support among peer-reviewed papers (and similar among their authors) that humans are warming the planet, the story made waves.
Naturally, however, those who disagree – usually not scientists – were not going to let the finding stand unchallenged. Responses claiming to find fault with Cook's methods have been numerous. One reply, unusual in being published in the peer-reviewed journal Environmental Research Letters, came from Professor Richard Tol of the University of Sussex, an economist who has long argued that humans will respond easily to the effects of warming, and only small actions should be taken to reduce emissions.
Now Cook and 15 other authors of past studies on the topic have responded in a new paper, again in Environmental Research Letters, collectively demonstrating that despite methodological differences their work has produced strikingly similar results, many of which Tol misinterpreted or misrepresented.
Polls on population groups' attitudes to climate change indicate greater knowledge brings more support for the view humans are warming the planet. University of Queensland, John Garrett
“Tol's erroneous conclusions stem from conflating the opinions of non-experts with experts and assuming that lack of affirmation equals dissent,” Cook and his co-authors write.
Cook told IFLScience that one study, led by Amsterdam University College's Dr. Bart Verheggen, compared the views of climate scientists to those expressed by people from other fields whose work only touched on climate. The second category included a subgroup selected for their outspokenness in disputing the human role in climate change. Tol, Cook said, treated this group as if it was representative of climate scientists, despite most having no qualifications or experience in the field, and so not even representing other scientists.
Cook's own work involved testing whether papers' abstracts endorsed or contradicted humans as the dominant factor in warming. “Tol effectively treats no-position abstracts as rejecting [human induced global warming]” the paper points out. Cook told IFLScience most of these papers “had a very narrow focus,” and didn't discuss topics such as causes in the limited space of an abstract.
He gave as an example of the misrepresentation of Tol's findings a paper studying alpine grasshoppers, which suggests global warming affects numbers, but doesn't discuss human responsibility, leading Tol to include it among the papers he claims don't support the consensus view.