Skip to main content

Sign up for our newsletter.

Quality journalism. Progressive values. Direct to your inbox.

A dried up area of the Folsom Lake reservoir in northern California. (Photo: Mr.Morgan.Murphy/cc/flickr)

New Study Shows California Droughts Driven by Climate Change and Here to Stay

Stanford researchers say human-driven global warming behind increasingly frequent and severe droughts, including current one

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."

"We've seen the effects of record heat on snow and soil moisture this year in California, and we know from this new research that climate change is increasing the probability of those warm and dry conditions occurring together," Diffenbaugh added.

Danielle Touma, a graduate student and co-author of the study, explained, "When we look at the historical record, not only do we see a doubling of the odds of a warm-dry year, but we also see a doubling of the frequency of drought years. Warm conditions reduce snowfall, increase snowmelt and increase water loss from soils and plants."

The researchers say their findings predict worse weather to come.

"We found that essentially all years are likely to be warm—or extremely warm—in California by the middle of the 21st century," said study co-author Daniel Swain, who is also a graduate student in Diffenbaugh's lab. "This means that both drought frequency—and the potential intensity of those droughts which do occur—will likely increase as temperatures continue to rise."


Our work is licensed under Creative Commons (CC BY-NC-ND 3.0). Feel free to republish and share widely.
We need your help.

Support progressive journalism.

Common Dreams is not your average news site. We don't survive on clicks or advertising dollars. We rely entirely on your support. And without it, our independent progressive journalism simply wouldn’t exist. Every gift of every amount matters.

Join the fight and support our common dreams today.

NYC Mayoral Candidate Eric Adams Rebuked for 'Dangerous' 400-Students-to-1-Teacher Theory

"Defunding schools to the point that we have a 400:1 student-to-teacher ratio so we can bankroll another huge expansion in an already-multibillion dollar police budget," said Rep. Ocasio-Cortez, "is how you build a school-to-prison pipeline."

Jon Queally, staff writer ·


Lack of Patent Waiver Would Add Over $70 Billion to Cost of Vaccinating World: Oxfam

Most of that money, said a spokesperson for the group, "will go directly into the pockets" of Big Pharma shareholders.

Jon Queally, staff writer ·


Darnella Frazier Receives Pulitzer Special Citation 'for Courageously Recording the Murder of George Floyd'

"Without Darnella, Derek Chauvin never would have been tried and George Floyd would have been blamed by the state for his own death."

Brett Wilkins, staff writer ·


'We Are Sounding the Alarm': Global Left Warns Right-Wing Fujimori Trying to Steal Election in Peru

"Fujimori’s only way forward to victory is simple: annul tens of thousands of already tallied votes," warned Progressive International. "Powerful forces are organizing to deliver this outcome."

Andrea Germanos, staff writer ·


'Climate Denial Masquerading as Bipartisanship': Progressives Reject Latest Infrastructure Compromise

"Refusing to act on climate means selling out future generations. The future of our planet and the health of our communities are non-negotiable."

Jake Johnson, staff writer ·