The American West’s megadrought deepened so much last year that it is now the driest in at least 1,200 years and is a worst-case climate change scenario playing out live, a new study finds. A dramatic drying in 2021 — about as dry as 2002 and one of the driest years ever recorded for the region — pushed the 22-year drought past the previous record-holder for megadroughts in the late 1500s and shows no signs of easing in the near future, according to a study Monday in the journal Nature Climate Change. The study calculated that 42% of this megadrought...