The drought of 2012 was more about unusual weather patterns than global warming, says a study. But its authors acknowledge the record-smashing event likely will be a puzzle for years to come.
Last summer's record-smashing drought in the US heartland was driven far more by natural variability in weather patterns than by global warming, according to a new analysis by a team of federal and university researchers.
The study represents what its authors call a first cut at untangling the factors contributing to the drought – particularly to the hardest-hit region in the Central Plains. The analysis does not explicitly exclude global warming as a player.
Instead, the researchers say that any one effect was too small to contribute to the time, place, and intensity of the drought in any significant way.
"The peculiar severity of summer 2012 can only be explained by an additional heavy role for random weather variability," the team concludes in a paper submitted to the Bulletin of the American Meteorological Society. The team's analysis also was released on Thursday as a 50-page report under the aegis of a federal drought task force led by the National Oceanic and Atmospheric Administration (NOAA).
The study touches on an event that has become a touchstone in the political debates over global warming's effect on the US.
It follows a report on weather extremes produced by the United Nations-sponsored Intergovernmental Panel on Climate Change. The report noted that on average, droughts in central North America "have become less frequent, less intense, or shorter." But the report also noted that over the course of this century, global warming's influence is likely to intensify droughts in the region.
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