California Withdraws Some Requests for Tighter Climate Rules

California has withdrawn requests that the Biden administration allow the state to enact limits on pollution from trucks, locomotives and ferries that are more strict than federal standards, on the expectation that the Trump administration would revoke them.

The move will leave the state, which has become a global leader in the fight against climate change, without some tools to lower planet-warming emissions at a moment when Los Angeles is being devastated by historic wildfires. Scientific studies have concluded that pollution from fossil fuels is intensifying wildfires in the West.

Under the 1970 Clean Air Act, the Environmental Protection Agency has for decades granted waivers to California, which has historically struggled with smog, to enact tougher pollution limits than those set by the federal government. Federal law also allows other states, under certain circumstances, to adopt California’s standards as their own.

Waivers can be used to rein in pollutants like soot, nitrogen dioxide and ozone that cause smog and lead to asthma and lung disease. But California officials have also used waivers to curb carbon dioxide, a chief cause of global warming. Gas powered cars and other forms of transportation are the biggest source of carbon dioxide generated by the United States.

Nearly all waivers requested by California have been granted, except during the first Trump administration, when President Donald J. Trump seemed to relish revoking California’s waiver to tighten state controls on pollution.

In December, the Biden administration granted California a waiver to enact one of the most ambitious climate policies in the world: a ban on the sale of new gasoline-powered vehicles in the state after 2035. Eleven other states plan to enact the same ban. Mr. Trump has already said he will revoke it. “California has imposed the most ridiculous car regulations anywhere in the world, with mandates to move to all electric cars,” Mr. Trump has said. “I will terminate that.”

California submitted requests to the E.P.A. more than a year ago to tighten controls on additional sources of pollution, including a requirement that commercial truck fleets begin a transition to all-electric or other zero emission vehicles, starting in 2024. Under those requests, now withdrawn, operators would have been required to achieve 100 percent zero-emissions fleets in the state between 2035 and 2042, depending on factors such as the size and weight of the trucks. The state also wanted to require that new heavy-duty trucks sold in California must be all-electric or zero-emissions by 2036.

Other withdrawn requests would have required operators of refrigerated trucks and trailers to begin transitioning to all-electric or zero-emissions fleets in 2024 and to reach 100 percent zero-emissions vehicles by 2030. The state also wanted to require operators of short-run ferries to use zero-emissions vessels by the end of 2025. And finally, it wanted railroad operators to begin transitioning to all-electric or zero-emissions locomotives in 2030, reaching 100 percent clean locomotives by 2053.

California regulators estimate that the rules, together, would have resulted in at least $50 billion in public health benefits because of avoided pollution.

E.P.A. officials said the agency had run out of time to review the waiver requests, prompting California to withdraw.

“Frankly, given that the Trump administration has not been publicly supportive of some of the strategies that we have deployed in these regulations, we thought it would be prudent to pull back and consider our options,” said Liane Randolph, chair of the California Air Resources Board, the state’s clean air and climate regulator.

Ann Carlson, who helped write the Biden administration’s policies to cut tailpipe emissions and now teaches law at the University of California, Los Angeles, said that the state’s inability to tighten limits on pollution from truck fleets was a particular blow.

“Trucks are a huge source of emissions and California has been leading on electrification of trucks, and the Trump administration is not going to fill the gap,” Ms. Carlson said.

She noted that although Mr. Trump has also said he would end federal support for electric vehicles, they now make up about 10 percent of the nation’s auto sales and have begun to find a global market.

The same is not yet true for electric trucks, which today make up less than 2 percent of heavy-duty vehicles sold in the United States.

Truck operators had criticized California’s plan.

“It set unrealistic time frames for converting a fleet over,” said Mike Tunnell, senior director of environmental affairs and research at the American Trucking Association. “It would increase your cost of transporting goods. The vehicles are much more expensive. The argument is that it saves money on fuel by going to with electricity, but it takes years to recoup that expense.”

Ms. Carlson and others said that they expected the state to find ways to use its own authority to curb emissions.

Gov. Gavin Newsom of California, who has publicly feuded with Mr. Trump for years, particularly over California’s authority to impose its vanguard climate programs, has developed plans to “Trump-proof” the state’s policies.

When Mr. Trump revoked the California waiver during his first administration, the state secretly struck legal agreements with four of the world’s largest automakers — Ford, Volkswagen, Honda and BMW — to reduce their tailpipe emissions according to limits set by California.

The state attorney general’s office has already begun outreach to companies to strategize on how to reach such agreements in the new Trump era.

The office hopes to create a foundation for such deals following its lawsuit last year accusing five of the world’s largest oil companies of knowingly contributing to climate damage, and its lawsuit last month alleging that Exxon Mobil misled consumers into believing that many plastic products were recyclable when they were not.

Regulators could also limit emissions stemming from vehicles that are linked to enormous facilities like warehouses that are a hub for diesel trucks. A similar rule recently took effect in Los Angeles.

“We still have some existing strategies,” Ms. Randolph said.