A total of 88,125 studies published from 2012 to 2020 were reviewed by experts from Cornell University in Ithaca, New York, to see how many of them linked human activity to the changing climate and look for consensus on global warming.
It builds on the work of a 2013 paper that analyzed all climate science papers published between 1991 and 2012, finding a 97 percent consensus.
‘We are virtually certain that the consensus is well over 99 percent now, said author Mark Lynas, who said it is ‘case closed’ for discussion of human-caused climate change.
The findings come as the UK is set to host the COP26 climate change conference, where world leaders will discuss, and potentially set new legally binding agreements that aim to keep global temperatures from rising out of control.
The current Paris Climate agreement, set at a UN conference five years ago, committed the world to actions that keep temperatures from rising more than 2.7°F (1.5°C).
To better understand the global climate change position among scientists rather than politicians or commentators, the team examined past papers.
The US-led team began by examining a random sample of 3,000 studies from the dataset of 88,125 English-language climate papers published from 2012 to 2020.
They found only four out of the 3,000 papers were skeptical of human-caused climate change, or about 0.14 percent of those initial papers.
‘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 said.
To find out whether there were more in the wider dataset, study co-author, Simon Perry, a UK software engineer, created a search algorithm.
It looked for keywords in the papers that were commonly used by human-caused climate change skeptics, such as solar, cosmic rays, and natural cycles.
The algorithm was applied to all 88,000-plus papers, and the program ordered them so the skeptical ones came higher in the order.
They found many of these dissenting papers near the top, as expected, with diminishing returns further down the list.
Overall, the search yielded 28 papers that were implicitly or explicitly skeptical, all published in minor journals.
‘If the 97 percent result from the 2013 study still left some doubt on the scientific consensus on the human influence on climate, the current findings go even further to allay any uncertainty, This pretty much should be the last word,’ said Lynas.
‘It’s critical to acknowledge the principal role of greenhouse gas emissions so that we can rapidly mobilize new solutions,’ said co-author Benjamin Houlton.
‘We are already witnessing in real-time the devastating impacts of climate-related disasters on businesses, people, and the economy,’ he added.
In spite of such results, public opinion polls as well as opinions of politicians and public representatives point to false beliefs and claim that ‘a significant debate still exists among scientists over the true cause of climate change,’ they found.
In 2016, the Pew Research Center found that only 27 percent of US adults believe that ‘almost all’ scientists agreed that climate change is due to human activity.