ITHACA, N.Y. — The climate change debate often leads to a lot of finger-pointing over who or what is to blame. According to researchers from Cornell University, all of humanity appears to be at fault for the current global warming dilemma. Their study finds over 99.9 percent of relevant scientific research agrees that climate change is mainly due to human actions.
Study authors included a total of 88,125 climate-related reports in this project, leaving virtually no room for doubt.
In many ways, this work builds upon a 2013 report that had come to similar conclusions. At the time that work reported 97 percent of studies between 1991 and 2012 validated the theory that human activities are changing our planet’s climate.
“We are virtually certain that the consensus is well over 99% now and that it’s pretty much case closed for any meaningful public conversation about the reality of human-caused climate change,” says first study author Mark Lynas, a visiting fellow at the Alliance for Science at Cornell, in a university release.
“It’s critical to acknowledge the principal role of greenhouse gas emissions so that we can rapidly mobilize new solutions, since we are already witnessing in real time the devastating impacts of climate related disasters on businesses, people and the economy,” adds study co-author Benjamin Houlton, Cornell’s Dean of the College of Agriculture and Life Sciences.
Is climate change a party-line issue?
In spite of these findings, most public opinion polls and surveys continue to indicate that significant portions of the population reject the notion that climate change is a man-made phenomenon. Of course, some refuse to believe global warming is legitimate at all. Researchers add that politicians and public figures promoting climate denial often exacerbate that issue.
For example, a 2016 survey found that only 27 percent of U.S. adults believed that the scientific community blames human behavior for climate change. A poll from this year suggests politics are playing an increasingly large role in the U.S. climate change debate, with more and more Americans feeling as if they need to “pick a side” that gels with the larger beliefs of their political party.
“To understand where a consensus exists, you have to be able to quantify it,” Lynas explains. “That means surveying the literature in a coherent and non-arbitrary way in order to avoid trading cherry-picked papers, which is often how these arguments are carried out in the public sphere.”
Little skepticism left among scientists
To start, this project’s authors gathered a random sample of 3,000 reports from a larger dataset of 88,125 climate studies published between 2012 and 2020. Among those 3,000 reports, just four expressed some doubt humanity’s role in causing climate change.
“We knew that [climate skeptical papers] were vanishingly small in terms of their occurrence, but we thought there still must be more in the 88,000,” Lynas comments.
So, study co-author Simon Perry, a United Kingdom-based software engineer and volunteer at the Alliance for Science, developed an algorithm capable of identifying specific words in studies that may indicate doubt regarding mankind’s role in climate change such as “solar,” “cosmic rays,” and “natural cycles.”
Still, even after applying the program to all 88,000-plus studies, only 28 studies published in minor journals suggested any type of skepticism to the man-made climate change theory.
“This pretty much should be the last word,” Lynas concludes.
The study appears in the journal Environmental Research Letters.