Researchers say global climate change added 8 to 27 percent of the severity of the ongoing drought in California, said the Los Angeles Times, citing a study in the journal Geophysical Research Letters. The scientists examined variations in drought and weather conditions at nearly 24,000 locations in California for the last 120 years as part of determining evaporation rates at each site. “By comparing changes over time and modeling a range of scenarios, the team calculated that at least 8 percent of the drought could be attributed to global climate change. The upper limit, they found, was no more than 27 percent,” said the story by reporter Louis Sahagun.
Bioclimatologist A. Park Williams of Columbia U, the leader of the study, said the results suggest that the drought is not the result of natural processes alone. Looking ahead, Williams said, the warmer temperatures that are part of climate change will make drought a prevalent weather condition by the 2060s.
In related news, new research by NASA says large parts of the Central Valley are sinking faster than expected because of massive withdrawals of groundwater, reports public radio KPCC-FM in Pasadena. In some places, ground levels are dropping by two inches a month. The state Department of Water Resources tentatively identified 21 groundwater basins and sub-basins that have been overdrafted by excessive pumping.