Monday, April 13, 2009

Punishing drought in Mexico suggests human influence

Newswise: University of Arkansas researchers and their colleagues have examined recent climate patterns in Mexico and determined that the country underwent severe drought conditions between 1994 and 2008, and that human changes related to land use and global warming may have aggravated the dry, warm conditions.

“This is one of the worst droughts in Mexico in the instrumental record,” said David Stahle, Distinguished Professor of geosciences at the University of Arkansas.

....The researchers looked at data from the Drought Area Index in Mexico, which uses tree ring chronologies and instrumental data on temperature and precipitation to reconstruct climate patterns in that country for the past 500 years. They found that the 10 years from 1994 to 2003 were some of the driest in the climate record, falling only behind the historic drought of the 1950s and the early colonial drought of the 1560s. However, they also found that the temperatures reached record highs during the more recent drought.

Droughts come and go, but the researchers believe that this drought in particular may have a human-generated component on both a regional and global scale.

…“Those are pathways by which humans are changing the natural systems globally and regionally,” Stahle said. “And these natural processes don’t necessarily conform to international borders. Those mechanisms may be in operation in the United States Southwest as well.”

Dry earth in Mexico's Sonoran Desert, shot by Tomas Castelazo, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported License.

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