The U.S. Environmental Protection Agency (EPA) has granted California a crucial waiver, allowing the state to move forward with its ambitious plan to phase out new gasoline-powered cars. This decision, however, sets the stage for potential legal challenges from the incoming Trump administration, which is likely to contest the waiver in court.
The EPA’s approval of the waiver greenlights California’s mandate requiring 35% of new car sales in 2026 to be zero-emission vehicles. This percentage will increase to 68% by 2030 and reach 100% by 2035. The vast majority of these zero-emission vehicles are powered by electricity.
The EPA also approved a 2020 California regulation aimed at reducing nitrogen oxides, a major component of smog, emitted by heavy-duty trucks and buses.
During a campaign event earlier this year, Donald Trump dismissed the notion of any state banning new gas-powered cars, stating emphatically, “I guarantee it — no way.” This stance suggests a potential shift in federal policy under his administration.
Karoline Leavitt, a Trump-Vance Transition spokesperson, said, “The American people re-elected President Trump by a resounding margin giving him a mandate to implement the promises he made on the campaign trail, including stopping attacks on gas-powered cars. When he takes office, President Trump will support the auto industry, allowing space for both gas-powered cars AND electric vehicles.”
California has a long history of setting its own vehicle emissions standards, which have significantly improved air quality across the state, particularly in the smog-prone Los Angeles basin and San Joaquin Valley. Cars and trucks are significant contributors to smog and soot, which can cause asthma, heart attacks, and other respiratory problems.
“California has longstanding authority to request waivers from EPA to protect its residents from dangerous air pollution coming from mobile sources like cars and trucks,” EPA Administrator Michael S. Regan stated. “Today’s actions follow through on EPA’s commitment to partner with states to reduce emissions and act on the threat of climate change.”
Ann Carlson, an environmental law professor at UCLA, believes the EPA’s decision to grant the waivers makes it harder for the Trump administration to overturn them. They would need to reverse a formal agency decision rather than simply deny a pending waiver request. Yet, Carlson anticipates legal battles over the rules will likely ensue.
Congress granted California the authority to set its own vehicle emissions standards in a 1967 clean-air law. However, each standard set requires a waiver from the EPA before it can be implemented. Under the Clean Air Act, the EPA can only legally reject a waiver if it is “arbitrary or capricious,” unnecessary to address air pollution, or technologically unfeasible due to inadequate lead time. No California waivers have ever been successfully revoked.
The Trump administration attempted to revoke part of a similar waiver in 2019 and tried to eliminate California’s authority to enact its own emissions and mileage rules for cars, but California and other states sued. In 2022, the Biden administration’s EPA approved a waiver for an earlier version of the zero-emission car rules, which led to a lawsuit from oil companies and certain Republican-led states.
Failure to comply with federal health standards for smog and soot could result in economic penalties, including the loss of highway funding, creating high stakes for the state.
Paul Cort, an attorney with Earthjustice, said, “This might read like checking a bureaucratic box, but EPA’s approval is a critical step forward in protecting our lungs from pollution and our wallets from the expenses of combustion fuels. The gradual shift in car sales to zero-emissions models will cut smog and household costs while growing California’s clean energy workforce.”
The Newsom administration has been actively urging the EPA to approve all of California’s clean-vehicle rules awaiting agency approval. Governor Gavin Newsom traveled to Washington, D.C., last month to advocate for action by the Biden administration before the change in presidential administrations.
“Clean cars are here to stay,” Newsom said. “Automakers and manufacturers have made it clear they intend to stick with California and consumers as we move toward clean cars that save people money. Naysayers like President-elect Trump would prefer to side with the oil industry over consumers and American automakers, but California will continue fostering new innovations in the market.”
Despite the commitment to electrifying transportation, challenges remain for the Golden State. Electric car sales, after an initial surge, have plateaued this year. Sales in the first nine months were up only 1.2% compared to the same period last year, a significant drop from 56% and 38% increases in the prior two years, respectively.
Assemblyman James Gallagher, a Republican from Chico, expressed skepticism, saying, “Never mind that the technology isn’t there and the charging infrastructure is falling apart. Never mind that this isn’t practical in rural areas or that people can’t afford to pay even higher up-front costs for cars. Newsom and his Democrat allies are all in on making life harder and more expensive for working Californians.”
The California Air Resources Board, responsible for enacting the state’s air pollution and climate regulations, has already shown signs of the influence of the upcoming election. The board recently withdrew at the last minute a proposed rule aimed at increasing sales of zero-emission motorcycles. This decision was partially attributed to Trump’s election, according to sources familiar with the board’s thinking. The state will instead offer incentives to purchase electric motorcycles.
The EPA is still reviewing six other California clean air rules, including measures to phase out diesel trucks and mandate cleaner locomotives, commercial ships, and off-road diesel vehicles. Regulations for trucks and locomotives are among the most contentious.
Harold Wimmer, president and CEO of the American Lung Association, stated, “We urge EPA to approve California’s remaining outstanding waivers and authorizations for other lifesaving clean air programs, allowing states to continue their long-standing commitment to air quality and public health protection.”
Last week, the Supreme Court decided to review whether the oil industry has the legal standing to challenge a lower court’s ruling that permitted California to set low- and zero-car emission standards for model years 2015 through 2025. The American Fuel & Petrochemical Manufacturers, representing the oil industry, stated that “the EPA’s authorization of the California ban and California’s ban itself are unlawful.”
The EPA’s new waiver approvals open the door to further legal disputes in the anticipated “Trump 2.0” era, potentially bringing these battles back before the conservative-leaning Supreme Court. Earlier this year, the Supreme Court overturned the “Chevron deference,” a 40-year-old legal principle that guided courts in interpreting how to apply Congressional laws.
Efforts to challenge California’s authority may also extend to Congress. The Congressional Review Act allows Congress to revoke federal rules approved during a defined timeframe at the end of an administration. However, legal experts are divided on whether this law would apply to EPA actions related to California’s clean-air waivers. Republicans might attempt to repeal the Clean Air Act provisions that empower California, but these attempts could face resistance, potentially including Democratic filibusters. Historically, bipartisan support for combating air pollution has thwarted similar moves to alter the Clean Air Act.
California’s clean-car mandate is also central to its climate strategy, establishing the state as a national leader in climate policy. Eleven other states and Washington, D.C., have adopted or plan to adopt its zero-emission car sales mandate. Automakers generally prefer a single national standard for vehicle emissions. However, they have collaborated with California officials for decades due to the state’s history, legal authority, and economic influence. Recognizing California’s substantial market share, many automakers have opted to negotiate with the state rather than contest the regulations.
In 2020, BMW, Ford, Honda, Volkswagen, and Volvo agreed to comply with California’s standards through 2026, regardless of federal actions. Stellantis committed to adhering to the zero-emission car sales requirements through 2030, even in the face of potential federal or judicial opposition. For 2026 models, 35% of sales in California must be zero emissions under the state rules; through September, they are only 25.4% of sales this year. The phased-in mandate allows for the sale of new plug-in hybrids as well as battery-only cars. The state anticipates some gasoline-powered cars will remain on California roads for over 25 years.
Significant obstacles remain, including the need for more public fast chargers. State officials estimate that California needs a million public charging stations in six years — almost ten times more than a year ago — and 2.1 million by 2035. The Alliance for Automotive Innovation, an auto industry group, said in a memo last week that it “will take a miracle” for states following California’s rules to reach 100% new zero-emission cars by 2035. John Bozzella, the group’s CEO, said, “Automakers are producing electric vehicles… but there’s a huge gap between these EV sales mandates and a customer’s reasonable expectation they can still choose what kind of vehicle to drive.”
