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By Tom Howarth
Science Reporter (Nature)
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A study published Thursday has put the blame for the wildfires ravaging parts of Los Angeles on an emerging climate phenomenon: hydroclimate whiplash.
This latest disaster comes on the heels of years of unprecedented weather swings, where periods of above-average rainfall are followed by extensive droughts.
Following record-breaking rains and snow in the winters of 2022-23 and 2023-24, California endured a blistering summer and a historically dry start to the 2025 rainy season. As a result, lush vegetation from the wet winters has become tinder-dry fuel, driving these devastating fires.
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Why This Matters
Hydroclimate whiplash is a growing global threat, intensifying the extremes of flooding and drought. In California, this cycle creates conditions for wildfires, landslides and water management crises.
The most recent blazes have already scorched nearly 30,000 acres in Los Angeles County, claiming the lives of five people. The fires remain largely uncontained.
What Is a Hydroclimate Whiplash?
"Hydroclimate whiplash" refers to sudden, dramatic swings between extreme wet and dry weather.
The study published Thursday in the online journal Nature Reviews Earth & Environment found that such events have become 31 to 66 percent more frequent globally since the mid-20th century and are fueled by climate change.
The main driver is the "expanding atmospheric sponge," as warming temperatures allow the atmosphere to hold and release 7 percent more water for every degree Celsius of warming.
How Has the Whiplash Helped Fuel the California Wildfires?
California's recent whiplash began with years of drought followed by consecutive winters of heavy rainfall that spurred vegetation growth.
By last summer, the same vegetation had dried out under record heat and continued dry conditions. Now, Santa Ana winds are spreading fires through this abundant, parched fuel.
While the wind patterns themselves may not have worsened because of climate change, the overlap of dry vegetation and seasonal winds has intensified wildfire risk.
Are Whiplash Events Becoming More Common?
Yes. Hydroclimate whiplash is accelerating faster than climate models predicted, according to the study, which was led by the University of California, Los Angeles.
By the end of this century, such swings could more than double if global temperatures rise by 3 degrees C. Regions across the globe, from California to the Middle East and South Asia, are expected to face worsening cycles of extreme wet and dry conditions.
What People Are Saying
Daniel Swain, lead author of the hydroclimate study, said in a statement: "This whiplash sequence in California has increased fire risk twofold: first, by greatly increasing the growth of flammable grass and brush in the months leading up to fire season, and then by drying it out to exceptionally high levels with the extreme dryness and warmth that followed.
"Substantial further increases in whiplash are likely in our future, and we really need to be accounting for this in risk assessments and adaptation activities," he said.
Rory Hadden, a fire science professor at the U.K.'s University of Edinburgh, who was not involved in the study, told Newsweek: "The snag here is that Southern California has seen very little rain for the last eight months or so. And so we've gone from this scenario with loads of rain promoting lots and lots of growth of vegetation to a scenario with not much rain for many months.
He continued: "The problem when you're dealing with nature, particularly with wildfires, is the timescales are on the order of years. You have to think about how you want to manage the fuel load and how you're going to protect yourself. But it does require long-term thinking, which is where a lot of the challenge lies in protecting ourselves against wildfire."
What Happens Next
It's too early to determine the exact cause of the current wildfires in L.A., but with conditions primed for ignition by the ongoing whiplash event, their occurrence was far from surprising. As California and other regions around the world grapple with the increasing frequency of hydroclimate whiplash, proactive planning—preparing for dry periods during wet ones and vice versa—will be critical to mitigating future disasters.
For Swain, both extreme rainfall and drought must be addressed together in the future, rather than treating them as separate issues. He highlighted the need for "co-management," a strategy that balances the challenges of managing large influxes of water during wet periods with the necessity of preparing for prolonged dry spells.
Hadden agreed, stressing the importance of carefully considering where homes are built and implementing strategies to manage vegetation near them, particularly after periods of heavy rainfall. These measures, he said, will be essential in mitigating the risk of similar disasters in the future.
Reference
Swain, D. L., Prein, A. F., Abatzoglou, J. T., Albano, C. M., Brunner, M., Diffenbaugh, N. S., Singh, D., Skinner, C. B., & Touma, D. (2025). Hydroclimate volatility on a warming Earth. Nature Reviews Earth & Environment, 6(1), 35–50. https://doi.org/10.1038/s43017-024-00624-z
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