SCIENTISTS have often been accused of exaggerating the threat of climate change, but it’s becoming increasingly clear that they ought to be more emphatic about the risk. The year just concluded is about to be declared the hottest one on record, and across the globe climate change is happening faster than scientists predicted.
Science is conservative, and new claims of knowledge are greeted with high degrees of skepticism. When Copernicus said the Earth orbited the sun, when Wegener said the continents drifted, and when Darwin said species evolved by natural selection, the burden of proof was on them to show that it was so. In the 18th and 19th centuries, this conservatism generally took the form of a demand for a large amount of evidence; in the 20th century, it took on the form of a demand for statistical significance.