“Reinforcing earlier studies, a new report published in the journal Science Advances says the U.S. Southwest faces between a 70 and 90 percent chance of megadroughts this century as planetary temperatures rise. Megadroughts have been linked to the demise of several pre-industrial civilizations. They are comparable to the worst droughts of the 20th century but are of much longer duration. Past megadroughts in the Southwest have lasted between 20 and 35 years, according to tree rings and other data. The Colorado River basin, which runs through parts of Arizona, Colorado, New Mexico, Nevada, Utah and California, has been experiencing an historic drought for the past 16 years. Lake Mead has dropped 130 feet during that time.

The study, which utilized computer modeling, says, “Business-as-usual emissions of greenhouse gasses will drive regional warming and drying, regardless of large precipitation uncertainties,” and that “an aggressive reduction in global greenhouse gas emissions (such as negotiated in the Paris climate agreement) cuts megadrought risks nearly in half.”

Another study, released last month in the journal Proceedings of the National Academy of Sciences, says that human-induced climate change has doubled the area affected by forest fires in the U.S. West over the last 30 years.”