There have been numerous studies examining the presence of a consensus (general agreement) among climate scientists regarding the anthropogenic nature of climate change. All of the articles that survey peer-reviewed-publishing climate scientists conclude the same thing:
“Climate scientists overwhelmingly agree that humans are causing recent global warming.”
Cook, J., Oreskes, N., Doran, P.T., Anderegg, W.R., Verheggen, B., Maibach, E.W., Carlton, J.S., Lewandowsky, S., Skuce, A.G., Green, S.A. and Nuccitelli, D., 2016. Consensus on consensus: a synthesis of consensus estimates on human-caused global warming. Environmental Research Letters, 11(4), p.048002. LINK
In a 2013 study examining nearly 12,000 peer-reviewed articles published over the course of 20 years by climate scientists, the researchers found that about a third of the papers’ abstracts (a paragraph-long summary of the paper) took some position on the anthropogenic nature of climate change and global warming. The other papers took no position on the issue and were likely focused on other specific processes of global warming. Of the third of the articles that did take a position, 97.1% agreed that human activity was the primary cause climate change, 0.7% rejected human causation, and 0.3% expressed uncertainty about human causes.
Other studies have engaged in slightly different methodologies, some refining the level expertise even more, and others have found a similar level of consensus (near 97%). See a review of the numerous studies here. Analysis shows that the more a study narrows in on a higher level of expertise, the higher the level of consensus. See the image below from this research. As the data points, labeled with a code for each respective article on the scientific consensus, move higher in the figure along the Y-axis, it represents greater consensus. As the data points are more to the right on the X-axis, the higher the level of expertise of the sampled scientists.
Among the American public there remains a misperception of the level of consensus among qualified scientists. According to the Consensus Handbook the public believes about two-thirds of scientists agree that the climate is warming and human activity is the primary cause. The figures below are from that handbook. Download a free pdf of the full handbook here from George Mason University’s Center for Climate Change Communication. Research shows that knowledge of the scientific consensus regarding anthropogenic climate change has positive influence on most people’s acceptance of the reality of global warming.