How has the scientific agreement on the anthropogenic nature of climate change evolved in 10 years?
Scientific support for the link between human activity and climate change has grown to the point that there is now almost universal agreement. While in 1996 reports covered statements with phrases such as “the balance of evidence suggests …” (Houston et al 1996), this evolved into “it is extremely likely that human influence was the cause. dominant warming observed since the mid-20th century â(Qin et al., 2014) and the more recent observation thatâ human influence on the climate system is now an established fact â(IPCC Technical Summary 2021).
A new article by an international team of researchers published today in Environmental research letters examines how the scientific consensus on anthropogenic global warming (AGW) has evolved over the past 10 years. The research study led by Krista Myers and Peter Doran of Louisiana State University, with John Cook of Monash University and John Kotcher and Teresa A. Myers of George Mason University is based on the results of a survey of scientists Earth survey conducted in September 2019. It follows the lead of a similar study conducted by Doran & Kendall Zimmermann in 2009.
âWhile there have been many studies that have found consensus among climatologists, there is little research on exactly how the accord has evolved over time and how different definitions of climate expertise shape this point of view, âsays John Cook. “This is the first time that the methodology of the 2009 study has been replicated to measure how climate consensus has strengthened over time.”
Of the 10,929 Earth scientists invited to participate in the survey, 2,780 responded. Across all definitions of climate expertise, survey responses indicated that there is a strong and robust consensus among geoscientists that the Earth’s temperature is warming primarily due to human activity.
Of all survey respondents who answered the primary question about the cause of global warming (n = 2,548), 91.1% responded that the Earth is warming primarily due to human activity. That’s about 11 percentage points higher than the 80% agreement found by the 2009 study when asking a similar question on AGW. Additionally, the authors found that 100% of the most active climate experts – those who each published 20 or more climate papers between 2015 and 2019 – accept that global warming is man-made.
âThe results show that consensus has grown in all areas. The results also reaffirm that consensus increases with the level of expertise – the more you know about climate science, the more likely you are to understand that humans are responsible for climate change. Almost 100% of the scientists in our most expert group who identify as climatologists and actively publish in peer-reviewed literature strongly agree that climate change is real and man-made â , says Peter Doran.
Analyzing the responses by sub-discipline, the authors found that those who identified as economic geologists had the lowest level of consensus with 84.1% agreeing with AGW. The 2009 Doran and Kendal Zimmerman study also found that economic geologists were the most skeptical, but with a much lower agreement of 47% with AGW, indicating a significant increase in consensus within this subgroup. over the past 10 years. The authors also found a sharp increase in the level of agreement on AGW among those who identify as meteorologists – from 64% in the 2009 study to 91% in the 2019 study.
The authors conclude that “given the persistent gap between the expert consensus on anthropogenic global warming and public understanding, it is imperative to strengthen efforts to engage and educate people on the scientific consensus on climate change. . Such efforts are essential to help our society make more informed decisions about how to stabilize our climate. “
Reference: âConsensus revisited: quantifying scientific agreement on climate change and climate expertise among Earth scientists 10 years laterâ 20 October 2021, Environmental research letters.
DOI: 10.1088 / 1748-9326 / ac2774