Projected number of extremely hot seasons per decade, 2010-2039. By 2039, most of the US could experience at least four seasons equally as intense as the hottest season ever recorded from 1951-1999, according to Stanford University climate scientists. In most of Utah, Colorado, Arizona and New Mexico, the number of extremely hot seasons could be as high as seven. Credit: Noah Diffenbaugh, Stanford University

ScienceDaily (July 9, 2010) — Exceptionally long heat waves and other hot events could become commonplace in the United States in the next 30 years, according to a new study by Stanford University climate scientists. “Using a large suite of climate model experiments, we see a clear emergence of much more intense, hot conditions in the U.S. within the next three decades,” said Noah Diffenbaugh, an assistant professor of environmental Earth system science at Stanford and the lead author of the study. Writing in the journal Geophysical Research Letters (GRL), Diffenbaugh concluded that hot temperature extremes could become frequent events in the U.S. by 2039, posing serious risks to agriculture and human health. “In the next 30 years, we could see an increase in heat waves like the one now occurring in the eastern United States or the kind that swept across Europe in 2003 that caused tens of thousands of fatalities,” said Diffenbaugh, a center fellow at Stanford’s Woods Institute for the Environment. “Those kinds of severe heat events also put enormous stress on major crops like corn, soybean, cotton and wine grapes, causing a significant reduction in yields.” The GRL study took two years to complete and is co-authored by Moetasim Ashfaq, a former Stanford postdoctoral fellow now at the Oak Ridge National Laboratory. The study comes on the heels of a recent NASA report, which concluded that the previous decade, January 2000 to December 2009, was the warmest on record. …  “Our results suggest that limiting global warming to 2 degrees Celsius above preindustrial conditions may not be sufficient to avoid serious increases in severely hot conditions,” Diffenbaugh said. …

Heat waves could be commonplace in the US by 2039