To the Editor:

This past week, two of the 2020 Democratic candidates for president released their plans for dealing with climate change, while many people are hearing some media outlets report that there is no scientific consensus on climate change, which suggests that climate plans aren’t needed. But what do they mean by “scientific consensus”? Scientists are trained to be skeptical — to challenge the conclusions made by other scientists. It is only after many different scientists arrive at the same conclusion based on many different studies that a concept is accepted as scientific fact. So what do scientists, as a group, really think about climate change?

In one of the larger surveys of scientists on this topic, over 3000 scientists were asked if they believed that humans are causing a change in climate. The proportion answering “yes” depended on the type of scientist, with 97% of climate scientists believing that human activity is significantly affecting climate change while only 77% of scientists in other fields believed this. In other words, scientists that are not climate experts are more likely to be skeptical of human-caused climate change, but still, most of them believe this is fact.

How questions are asked also affects survey results. In a survey conducted in 2012 of several hundred scientists working in academia, industry, and government, 90% of the scientists said that human activity is a primary cause of climate change, and another 10% said humans are a secondary cause of climate change. None of the scientists in this survey thought humans have no effect on climate change or that climate change was not occurring. 

All in all, given the training of scientists to be skeptical, it’s pretty amazing that so many of them accept climate change as fact. This scientific agreement is also seen in the many National Academies of Science across the globe that have endorsed the science supporting climate change. These National Academies represent countries with very different world views including the United States, Russia, China, India, Brazil, Venezuela, South Africa, Israel, Iran, and all countries in the European Union. So, if you define scientific consensus as unanimous agreement (absolutely nobody disagrees), there probably isn’t anything that scientists have consensus on, but if you define consensus as agreement by most, there certainly is scientific consensus on climate change.

D. McCoy

Elizabethton