By Marlene Cimons
14 June 2013
(LiveScience) – Drought has beset the Earth since before farming began. In developing nations, it brings suffering and death. In wealthier countries like the United States, it brings economic devastation when crops wither and die, and forests burn.
The United States continues to feel the aftereffects of the 2012 drought , the most severe and extensive in nearly half a century, during the hottest year on record. It affected about 80 percent of the nation's farmland, making it more widespread than any drought since the 1950s, according to the U.S. Department of Agriculture (USDA).
The drought destroyed or damaged portions of major field crops in the Midwest — particularly, field corn and soybeans — causing hikes in farm prices and leading to other shortages in animal feed, including hay and grasses. Those price spikes, in turn, are prompting increases in the retail prices of beef, pork, poultry and dairy products.
More importantly, the threat posed by drought could become even greater as the planet heats up, especially in parts of the U.S. — and the world — that already are dry.
"Droughts are a normal part of the climate cycle that we should expect and plan for, but there will be more stress under increased temperatures,'' said Mark Svoboda, a climatologist with the National Drought Mitigation Center at the University of Nebraska-Lincoln. "The roller-coaster ride will just get rockier. Climate change will put some more double loops into that roller-coaster ride.''
Places with a wet season and a dry season generally will become wetter in the wet season and drier in the dry season, and areas that now tend to be dry most of the year likely will suffer more intense drought. This also will result in less water for drinking, less water for agriculture and less water for recreation.
Drought typically afflicts a third of the nation's counties each year, according to the USDA. In recent history, the U.S. has experienced a number of persistent droughts, including the notoriously famous Dust Bowl of the 1930s. The Southern Plains and the Southwest endured a serious drought in the 1950s, as did the entire West from 1998 until summer 2004. A merciless drought began in Texas in October 2010, continued throughout 2011 and still affects parts of the state.
To be sure, the 2012 drought was due, in part, to natural climate variability — in this case, the La Niña event that began in fall 2010. La Niña conditions change weather patterns over the Pacific Ocean and North America, steering storms north of where they usually occur, depriving the already-arid Southwest of much-needed rainfall. But the unrelenting hot temperatures made things worse.
"This drought wasn't unusually long, but it was unusually hot,'' said Jonathan Overpeck, co-director of the Institute of the Environment at the University of Arizona. "That's what makes this a global-warming-style drought. It has much bigger impacts because it is a hot drought.'' [more]