Scientists say global warming will worsen California drought
WASHINGTON – New research shows the fingerprints of global warming in worsening the California drought and suggests a future of more dryness for the suffering state.
A major new study released Thursday adds to the growing scientific consensus that rising temperatures linked to the burning of fossil fuels are intensifying the crisis, although climate scientists believe natural weather variations are responsible for the lack of rainfall that created the drought.
The study in the journal Geophysical Research Letters estimates that global warming has worsened California’s drought by 15 percent to 20 percent, the first time a figure has been placed on the phenomenon.
“The current drought in California would still be occurring just based on pure natural climate variability,” the lead author of the study, Columbia University climate scientist A. Park Williams, said in an interview. “But over the last 120 to 130 years, as the greenhouse gases have been accumulating in the atmosphere, there has been this extra thing going on.”
What’s happening is the warming atmosphere robs moisture from plants and soil on the surface, he said.
“A lot of people think that the amount of rain that falls out the sky is the only thing that matters,” Williams said. “But warming changes the baseline amount of water that’s available to us, because it sends water back into the sky.”
The study adds to earlier research from scientists like Noah Diffenbaugh, a climatologist at Stanford University.
“We’re seeing more and more the role of temperature in intensifying the drought and prolonging the drought,” Diffenbaugh said in an interview.
His research shows drought is far more likely to happen at higher temperatures and that California’s warming trend is increasing the chances for more droughts in the state’s future.
Scientists said it could be just a temporary reprieve when California’s rains resume, which might happen this winter.
California is in the fourth year of the drought.