Climate-Change Consensus

I greatly enjoyed “Science Under Attack” by Seth Shostak ’65 (feature, March 22), but was surprised to see an erroneous statement in the first paragraph. The percent of climate scientists who dispute that climate change is occurring and is due to human activities is much lower than 13 percent. It is in the low single digits, maybe 3 percent or less. A 97 percent agreement of climate scientists is given by NASA in its assessment of this question (see https://climate.nasa.gov/scientific-consensus/). NASA quotes a 2016 paper by Cook et al. in Environmental Research Letters that examines this in detail, affirming the overwhelming consensus represented by 97 percent agreement among climate scientists that climate change is occurring and is mainly caused by human activities.

Editor’s note: Seth Shostak agreed that the percentage of climate scientists who dispute that climate change is largely caused by humans should have been reported as 3 percent, based on the NASA report. He added that an analysis by James Powell, published in Skeptical Inquirer magazine in December 2015, argued that “due to selection effects,” the actual percentage “is at least 99.9 percent.”