More frequent and intense wildfires are making it harder for homeowners to find and keep insurance in California, a state regulator warned Thursday.

“The problem of insurance availability is going to expand” after last year’s record-breaking wildfires, California Insurance Commissioner Dave Jones said in an interview Thursday. He said growing rates of non-renewal and rate increases for people in wildfire zones are “entering a critical stage.”

Wildfires were already pinching the availability of coverage in large sections of the state, new data show. The number of homeowners in fire-prone areas who complained about getting dropped by their plans increased 250 percent from 2010 to 2016, Jones’s department reported Thursday. In the 24 counties with the greatest wildfire risk, the number of policies canceled by companies increased 15 percent between 2015 and 2016 alone; in at least six of those counties, that number grew by more than 50 percent.

California was struck by a series of wildfires starting last fall that damaged or destroyed more than 14,700 homes, according to the regulator. Those losses resulted in “more than $9 billion in insured damages so far.” One Southern California fire started in December, known as the Thomas Fire, burned more acreage than any other blaze in the state’s history.

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The pressure on California’s market is a warning for states elsewhere, according to climate and industry experts. The number of acres consumed by wildfires each year has doubled since 2000, according to federal data. The Union of Concerned Scientists warns that warmer and drier conditions caused by climate change will mean even more fires. Meanwhile the number of people who live in the most fire-prone areas keeps growing.

“We used to have in this country a wildfire season, and now we have wildfire risk in multiple states all year long,” said Julie Rochman, president of the Insurance Institute for Business & Home Safety, an industry-funded research group that looks at how to make homes more resilient to extreme weather. She said rising premiums in California reflect the growing exposure to wildfires, and people in other states could gradually see their rates become harder to afford as well.

In Thursday’s report, the regulator urged lawmakers for changes that would make it harder for companies to increase rates or cancel coverage. Those proposals include preventing carriers from dropping homeowners that take specific steps to reduce their wildfire exposure, requiring insurers to seek state approval for the models they use to calculate wildfire risk, and letting homeowners appeal those risk calculations.

Providers of residential coverage say they will resist any changes that make it harder for them to sell policies that reflect the true risk of wildfires. That would force insurers to charge higher premiums in safer parts of the state, according to Rex Frazier, president of the Personal Insurance Federation of California, which represents the industry.

“Of course, people who choose to live in the forest and local governments that continue to approve development in the forest would like less fire-prone areas to subsidize them,” Frazier said by email. “But that just ‘solves’ one problem by creating another.”

Insurers weren’t the only ones to warn about reducing the cost of coverage in wildfire zones. Alice Hill, a senior adviser on climate resilience to President Barack Obama, said people thinking about buying homes in wildfire areas should instead use the cost of protection as an indication of whether it’s a good idea to buy there.

“When we see insurers pulling back from markets, it’s because the risk is increasing,” Hill, a research fellow at the Hoover Institution, said by phone. “If those risks are getting too high, it’s a strong signal that we need to change our ways.”

Jones said he supports changes to local planning and regulations to avoid putting people in dangerous areas in the first place. But he called higher rates “a very crude tool” to accomplish that.

“By the time the insurance price signal is being sent, the homes are built, the businesses are built and people are moving in,” Jones said. “If you wait and try to rely on insurance as a way of getting better decisions made, it’s too late.”

Rochman, of the institute, said higher prices in California and elsewhere are more likely to produce still-more generous government assistance, subsidizing people’s desire to live where they want, despite the risk.

“We’re going to continue to shovel millions and billions of dollars in disaster recovery out the door,” Rochman said. “We’re not a country that likes brutal honesty.”