The American West is experiencing the worst drought in at least 1,200 years, new research shows, and climate change is responsible for 42 percent of its severity. The drought, which began in 2000 and has taken a toll on water supplies and fueled wildfires across the region, had previously been considered the worst in 500 years but a dramatic drying in 2021, when about two-thirds of the American West was in extreme drought, “really pushed it over the top,” A. Park Williams, a climate scientist and study author, told the New York Times.

“The drought conditions [are] substantially worse because of climate change, but there is quite a bit of room for [the drought] to get even worse,” Park explained to the LA Times. Park and his colleagues examined tree rings at about 1,600 sites across the region, from Montana to California and northern Mexico. The study, which was published in the journal Nature Climate Change, warns that we “need to be even preparing for conditions in the future that are far worse than this.” (AP, NPR, ABC, CNN, Axios, CNBC, The Hill, LA Times $, Wall Street Journal $, Bloomberg $, San Francisco Chronicle, New York Times $)