America’s trees are dying at an alarming rate in the nation's western forests, a new study says. Death rates have more than doubled over the last two to three decades, Time reports, even in seemingly healthy locales. All types and sizes of trees, and at all elevations, have been affected. The likely culprit: longer, hotter summers and scarce water linked to global warming, says the US Geological study.
“If you were walking around these forests you'd think everything was fine," says one researcher. "But when you have the long view, it's very worrying.” Researchers say that large-scale die-offs are possible, a development that would release yet more carbon dioxide into the air and make the trees' plight even worse.