Stanford scientists say the risk of drought in California is being increased by climate change caused by human activity, reports the Contra Costa Times. It quotes climate scientist Noah Diffenbaugh as saying continued warming “will result in more frequent occurrences of high temperatures and low precipitation that will lead to increased severe drought conditions.” The Stanford study says there were six droughts in the past 20 years, compared to 14 droughts in the preceding century.
NBC News quoted Diffenbaugh as saying, “Human emissions of greenhouse gases have increased the probability that when low precipitation years occur, they occur with a warm environment.” Warmer weather will mean that when dry years arrive, conditions will be more conducive to drought.
The study, “Anthropogenic warming has increased drought risk in California,” was published in the Proceedings of the National Academy of Sciences (PNAS) and is available here.
Another study in PNAS says climate change was the likely cause of drought in Syria from 2006-09, and the drought contributed to the outbreak of civil war in the Middle Eastern nation, according to the New York Times. The drought, the worst in modern times, led to crop failures that displaced 1.5 million people and exacerbated social stresses, said the researchers. The Times quotes the lead author of the study as saying, “A drought this severe was two to three times more likely” due to the shift to warmer and drier weather in the eastern Mediterranean.