A recent study led by Robert Allen, an earth scientist at the University of California, Riverside, sheds new light on how climate change may impact weather patterns in California, and the results may not be what you would expect.

Despite fears that climate change could result in persistent, year-round droughts across the state, Allen’s research suggests that this is unlikely.

Rather, global warming will likely lead to greater precipitation in the state overall, though precipitation will be almost entirely limited to the winter months, resulting in drier conditions during the summer and heavy rainfall and flooding during the winter.

From 2011 to 2017, California experienced one of the most severe droughts in recent history — one of the worst, by some estimates, since the 1400s. The drought, seen as a perceptible manifestation of climate change, captured the attention of more than just the climate science community.

It had significant effects on the daily life of Californians and severe effects on wildlife and forestry across the state. The drought killed over 100 million trees, forced Governor Jerry Brown to institute mandatory 25 percent water restrictions in 2015, and threatened to destroy entire populations of salmon.

The drought ended in early 2017, only to be followed by major precipitation, causing floods across the state over the first half of the year. This rainy period, too, was historically significant — it was the wettest winter in almost a full century of recordkeeping.

According to the new study, extreme weather patterns could be the new normal for the state of California.

The new research builds on a study that Allen published in 2017, which showed that precipitation would likely increase in California due to warming sea surface temperatures.

The new study draws attention to the effects of warming sea surface temperatures in the tropical Pacific — such as those observed during El Niño events — on drought conditions.

“We show that drought in California is related to tropical Pacific sea surface temperatures, and more specifically, warming and cooling of the central and eastern tropical Pacific,” said Allen.

His conclusion: “During warm episodes (El Niño), drought is less likely. During cold episodes, drought is more likely.”

Allen, along with co-author Ray Anderson, a research soil scientist at the USDA-ARS US Salinity Lab, compared the predictions of 40 climate models that simulated weather patterns to actual records of precipitation, soil moisture and streamflow in California between 1950 and 2000.

Once they determined which models were more accurate, they looked at how these models predicted drought conditions in the future, assuming that greenhouse gas emissions continue at their current rates.

They found that the more accurate models showed a reduced risk of drought during the wet season and increased drought risk during the dry season.

Essentially, more rain in the winter, less rain in the summer.

So what does this mean for Californians? How can people and policymakers prepare for, or try to mitigate, more extreme weather patterns?

“Mitigation, by definition, involves reducing greenhouse gas emissions,” said Allen. “So this is an obvious solution, that can be accomplished in a number of ways. But the main way of reducing greenhouse gas emissions is to phase out fossil fuels for energy generation and replace them with renewable energy sources.”

But Allen emphasized that heavier winter rains and drier summer months are a reality that California will have to live with, and adapt to.

Historically, about 90 percent of California’s rain and snow already come during the winter months. Changes in precipitation patterns will likely exacerbate the climate variations that California already experiences.

This could mean more floods and mudslides, as we saw during the wet winter of 2017, followed by more severe fire seasons. Heavy winter rains result in lush spring growth, which quickly dries up during the summers, creating ample fuel for wildfires across the state.

We’re already seeing these effects in action. In 2017, the wet winter led to the most destructive wildfire season on record, causing billions of dollars in damages.

“I think it’s here now, so we need to start acting as quickly as possible,” Allen said in a statement. “Adaptation is incredibly important in response to climate change, and in this case it means enhancing our water storage capabilities, our reservoirs and dam structures, because things are going to become drier in the nonwinter months.”

Individuals can help in sustainability efforts by using rain barrels and planting native plants.

“In Southern California, it could mean having native plants in your yard because a grass yard has to be irrigated, and that’s probably not the wisest use of water,” Allen said in a statement. “It’s all about living sustainably.”