Los Angeles is burning and scientists say it’s no accident. After two extremely wet winters that spurred explosive plant growth, 2024 brought record heat and a bone-dry start to what should be the rainy season. The result? Dangerous wildfires fueled by all that dried-out vegetation.
This whiplash between wet and dry extremes isn’t just a California phenomenon. New research published today in Nature Reviews reveals these dramatic climate swings have increased globally by up to 66% since the mid-20th century, with the rate of change accelerating as the planet warms.
The Expanding Atmospheric Sponge
“The expanding atmospheric sponge effect may offer a unifying explanation for some of the most visible, visceral impacts of climate change that recently seem to have accelerated,” explains lead author Daniel Swain, a climate scientist with UCLA and UC Agriculture and Natural Resources.
The science behind this acceleration is straightforward but alarming: For every degree Celsius of warming, the atmosphere can hold 7% more water. Like compound interest in a bank, as Swain notes, “The problem is that the sponge grows exponentially. The rate of expansion increases with each fraction of a degree of warming.”
A Global Pattern of Extremes
The research team found the strongest increases in climate whiplash across northern Africa, the Middle East, South Asia, northern Eurasia, and the tropical Pacific and Atlantic regions. Most other areas will also experience more volatile swings between wet and dry conditions.
“Increasing hydroclimate whiplash may turn out to be one of the more universal global changes on a warming Earth,” Swain says.
The researchers synthesized hundreds of previous studies to document how these rapid transitions can trigger cascading disasters. When heavy rains follow drought and fires, the parched, damaged soil can’t absorb water effectively, leading to flash floods and landslides. Meanwhile, wet periods that fuel plant growth followed by intense dry spells create abundant fuel for wildfires.
“We can’t look at just extreme rainfall or extreme droughts alone, because we have to safely manage these increasingly enormous influxes of water, while also preparing for progressively drier interludes,” Swain explains.
California offers a preview of what other regions might face. Co-author John Abatzoglou, a UC Merced climate scientist, notes: “Hydroclimate in California is reliably unreliable. However, swings like we saw a couple years ago, going from one of the driest three-year periods in a century to the once-in-a-lifetime spring 2023 snowpack, both tested our water-infrastructure systems and furthered conversations about floodwater management.”
A Race Against Time
“The less warming there is, the less of an increase in hydroclimate whiplash we’re going to see,” Swain says. However, he warns that we’re currently on track for between 2 and 3 degrees Celsius of global warming this century, meaning substantial increases in these climate swings are likely inevitable.
The message is clear: Communities worldwide need to prepare not just for individual extremes of flood or drought, but for their increasingly rapid alternation. The research suggests that traditional approaches to water management and infrastructure design may need fundamental rethinking to handle these accelerating climate swings.