Scientific Consensus Is Clear Humans Cause Climate Change Ahead of COP26 Summit

More than 99.9 percent of peer-reviewed scientific studies agree that the main driving factor of climate change is human activity.

That is the conclusion reached in a survey of almost 90,000 climate-related studies. The research is published in a new paper published in the journal Environmental Research Letters.

The paper acts as a follow-up to similar research reviews published in 2013, which looked at research published between 1991 and 2012 and revealed 97 percent agreement that human activities are causing climate change.

This new paper looks at scientific literature published between 2012 and November 2020. It shows that the consensus on this issue of human-driven, or anthropogenic, climate change, has only strengthened over the last eight years.

"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," visiting fellow at the Alliance for Science and the paper's first author, Mark Lynas, said in a Cornell University press release.

The revelation comes ahead of the UN Climate Change Conference (COP26) scheduled to begin on October 31 in Glasgow, Scotland.

The conference will see delegates gather to discuss the goals of the Paris Agreement, particularly the target of keeping warming below 2 degrees Celsius (3.6 F).

The Ronald P. Lynch dean of the College of Agriculture and Life Sciences, Benjamin Houlton, was also an author on the review paper. He added: "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."

The findings highlight a stark disparity between what scientists have found regarding climate change and the consensus of science and what the American public thinks that scientists believe.

In a 2016 survey, the Pew Research Center asked the U.S. public about their climate change beliefs and opinions. This research showed that 27 percent of Americans believe that the majority of scientists think that climate change is driven by human activity. Of the survey's respondents, 35 percent answered that over half of scientists believed this was the case.

An equal number of people to this believed either that less than half of scientists believe human activity is driving climate change or that no scientists believe this, 20 percent and 15 percent of respondents respectively.

"To understand where a consensus exists, you have to be able to quantify it," Lynas said. "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."

Lynas and his coauthors took 88,125 English language climate research studies and from this selected 3,000 at random. Within this sample, only four papers were skeptical of the idea that human activities are the major contributing factor of climate change.

The small number of skeptical papers even took the authors of the research by surprise. Lynas added: "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."

To check their results the team turned to UK-based software engineer and volunteer at the Alliance for Science, Simon Perry, who created an algorithm to sweep the 88,125 papers for phrases common in papers that are skeptical of anthropogenic climate change.

This search yielded just 28 papers that were considered skeptical of human-driven climate change. That means the first search of 3,000 papers revealed a percentage of 0.13 skeptical papers. The search of the entire selection revealed skeptical papers accounted for just 0.0003 percent of all the studies.

This means 99.9997 percent of the near 90,000 papers supported the idea that humans are causing climate change. The authors added that none of the skeptical papers were published in major journals.

If the 2013 study's result of 97 percent consensus in the scientific community on anthropogenic climate change left any room for doubt, Lynas believes that this new study should end climate uncertainty conclusively. He said: "This pretty much should be the last word."

There is no Planet B
A protestor holds a sign reading "There is no planet B" in a stock image. A new review of almost 90,000 climate papers reveals there is 99.9 percent consensus that human activities are driving climate change. DA4554/getty