Arizona Republic: Drought will kill piñon pine trees at an even faster rate as temperatures increase across the Southwest, according to a study released today by researchers at the University of Arizona. In a controlled experiment at the enclosed Biosphere 2 project near Oracle, scientists documented tree deaths occurring 28 percent faster when the temperature was increased 4 degrees Celsius. Researchers predicted that, over 100 years, widespread tree deaths related to drought would occur five times …