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

Sarah Lazare

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've had enough. The 1% own and operate the corporate media. They are doing everything they can to defend the status quo, squash dissent and protect the wealthy and the powerful. The Common Dreams media model is different. We cover the news that matters to the 99%. Our mission? To inform. To inspire. To ignite change for the common good. How? Nonprofit. Independent. Reader-supported. Free to read. Free to republish. Free to share. With no advertising. No paywalls. No selling of your data. Thousands of small donations fund our newsroom and allow us to continue publishing. Can you chip in? We can't do it without you. Thank you.

Protesting Fuel Poverty, People Tell UK Government to 'Keep Everyone Warm This Winter'

As energy bills—and fossil fuel profits—continue to soar, demonstrators around Britain demanded immediate action from Prime Minister Rishi Sunak and members of Parliament.

Kenny Stancil ·


'Turn Off the Tap on Plastic,' UN Chief Declares Amid Debate Over New Global Treaty

"Plastics are fossil fuels in another form," said U.N. Secretary-General António Guterres, "and pose a serious threat to human rights, the climate, and biodiversity."

Kenny Stancil ·


EPA Urged to 'Finish the Job' After Latest Move to Protect Bristol Bay From Pebble Mine

"Local residents, scientists, and the broader public all agree that this is quite simply a bad place for a mine, and it is past time for the EPA to take Pebble off the table permanently," said one activist in Alaska.

Jessica Corbett ·


'Zero Tolerance for Corruption': Grijalva, Porter Demand Answers on Alleged Trump Pardon Bribery Scheme

The Democrats believe a real estate developer donated to a Trump-aligned super PAC in exchange for the pardons of two other men.

Julia Conley ·


Millions of Americans Lack Adequate Health Coverage, But the Pentagon Has a New Nuclear Bomber to Flaunt

"This ominous death machine, with its price tag of $750 million a pop, brings huge profits to Northrop Grumman but takes our society one more step down the road of spiritual death," peace activist Medea Benjamin said of the new B-21 Raider.

Brett Wilkins ·

Common Dreams Logo