Scientific American: The short, bushy pinyon pine thrives in the arid climate of the U.S. Southwest, where there may be little or no rain for months or even years. Yet, a drought that began in 2000 killed some 10 percent of the pines in the Four Corners region where Arizona, Colorado, New Mexico and Utah meet–even in moister, high-elevation areas–and scientists wondered if the warmer temperatures resulting from climate change might be the cause. So ecologist Henry Adams, a doctoral candidate at the …