ScienceDaily: Widespread die-off of piñon pine across the southwestern United States during future droughts will occur at least five times faster if climate warms by 4 degrees Celsius, even if future droughts are no worse than droughts of the past century, scientists have discovered in experiments conducted at the University of Arizona’s Biosphere 2. Their study is the first to isolate the impact of just temperature on tree mortality during drought. The temperature effect is usually confounded by …