The Southwest, including California, along with the Great Plains states, will endure long-lasting “megadroughts” in the second half of this century, worse by far than anything seen in the past 1,000 years, a team of climate experts said Thursday.
The driving force behind the devastating droughts? Human-induced global warming, the team reported.
The new forecast is based on models of continued climate change that consider the slow pace of many nations to curb their output of greenhouse gases. The scientists contend there is at least a 20 percent chance that coming droughts will last 35 years or more, and a 50 percent chance that they will last 10 years or more.
“When you stack these model projections against the reconstruction of past climates, the results are so sobering that they have me ready to go out for a drink,” said Ken Caldeira, a climate scientist at the Carnegie Institution for Science and Stanford University, in an e-mail.
Caldeira, who was not connected with the study, said the scientists’ forecasts are based on “the most reliable model results available in the world today.”
Current drought unrelated
The report comes as California remains in a severe drought, but a leading scientist on the project said the current drought is not directly connected to the new forecast. “I do, however, want to be clear that our results do not say anything about the current and ongoing drought in California,” said climate scientist Benjamin I. Cook of the NASA Goddard Institute for Space Studies.
Cook worked with Toby R. Ault of Cornell University and Jason E. Smerdon of Columbia University’s Lamont-Doherty Earth Observatory to arrive at the forecast of an “unprecedented 21st century drought risk.”
Their report appears Friday in the new peer-reviewed journal Science Advances, published by the American Association for the Advancement of Science in Washington, which is meeting this week in San Jose.
The prediction of megadroughts, the report’s authors say, “contrasts sharply with the recent emphasis on uncertainty” in drought forecasts by the Intergovernmental Panel on Climate Change, which is considered the authoritative international agency on climate change.
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SOURCE: SF Gate, David Perlman