California’s trees are dying at an alarming rate. Late last week, the U.S. Forest Service said an aerial survey revealed that 36 million additional trees had died while in the grip of persistent drought, bringing the total since 2010 to more than 102 million. Those numbers have startled California officials and scientists while adding urgency to a long-simmering debate over what should be done about it. The tree deaths have been concentrated in the southern and central Sierra Nevada, but experts warn of increasing deaths in forests all the way up to the Oregon border.