The increasingly frequent and severe droughts that have punished California over the past two decades—including the current record-breaking one—are primarily the result of human-caused climate change and will likely grow even worse, scientists at Stanford University warn.
Published in Monday’s issue of the journal Proceedings of the National Academy of Sciences, the new research analyzes historical records, as well as computer simulations of global warming, to investigate the role of changing temperatures during California droughts over the last 120 years.
The researchers concluded that human-driven global warming is exacerbating and increasing the confluent warm and dry conditions that have produced the state’s most severe droughts.
“Of course low precipitation is a prerequisite for drought, but less rain and snowfall alone don’t ensure a drought will happen,” explained Stanford professor and lead author Noah Diffenbaugh. “It really matters if the lack of precipitation happens during a warm or cool year.”