California and 23 other states sued the Environmental Protection Agency on Friday, asking a federal court to block the Trump administration from stripping the nation’s most populous state of its long-standing authority to set strict fuel-efficiency standards on cars and trucks within its borders.
“We’ve said it before, and we will say it again: California will not back down when it comes to protecting our people and our environment from preventable pollution,” the state’s attorney general, Xavier Becerra, said in a statement announcing the action. “No matter how many times the Trump administration attempts to sabotage our environmental progress, we will fight for clean air.”
The lawsuit, filed in the U.S. Court of Appeals for the District of Columbia Circuit, marks the latest round in an escalating fight between the White House and California officials over how quickly the nation’s auto fleet must increase its fuel-efficiency. Already, the feud has led to several legal skirmishes, a divided automotive industry and uncertainty in the nation’s car market.
In mid-September, the Trump administration acted to revoke California’s decades-old ability to set air pollution standards for cars, pickup trucks and SUVs that go beyond those required by the federal government. California’s authority to set such standards dates back to the Clean Air Act of 1970.
The administration’s move was a high-profile example in a broad campaign to undermine Obama-era policies aimed at cutting greenhouse gas emissions that fuel climate change.
“We embrace federalism and the role of the states, but federalism does not mean that one state can dictate standards for the nation,” EPA Administrator Andrew Wheeler said in a speech to the National Automobile Dealers Association at the time.
Within days, California and 22 other states, along with several cities, filed a federal lawsuit against the National Highway Traffic Safety Administration. That suit argued that the efforts to preempt California from setting more ambitious emissions standards “exceeds NHTSA’s authority, contravenes Congressional intent, and is arbitrary and capricious, and because NHTSA has failed to conduct the analysis required under the National Environmental Policy Act.”
The latest filing in the D.C. Circuit also includes a petition asking the court to review NHTSA’s effort to preempt California’s right to set tailpipe emission standards.
The current standoff began last year, when NHTSA and EPA jointly issued the Trump administration’s proposal last year to revoke California’s “waiver” as part of a rule that would freeze mileage standards for these vehicles at roughly 37 miles per gallon from 2020 to 2026. The Obama-era standards had required these fleets to average nearly 51 mpg by model year 2025.
In July, California forged an agreement after months of secret negotiations with four companies – Ford, Honda, Volkswagen and BMW of North America – under which they pledged to produce fleets averaging nearly 50 mpg by model year 2026. The Justice Department has opened an inquiry into whether that accord violated antitrust law.
Meanwhile, last month other automakers including General Motors, Toyota and Fiat Chrysler, intervened in ongoing litigation on behalf of the Trump administration, saying they support increased fuel efficiency but that the federal government has the “sole purview” for setting national standards.
The episode has exposed an rare policy rift within the automotive industry – one that could pit powerful auto manufacturers industry giants against one another in a protracted legal battle.
Emissions from the transportation sector, including cars and trucks, now rank as the largest single source of greenhouse gases in the United States.
And while some of the largest auto manufacturers have now sided with the Trump administration in its legal fight with California, Americans themselves appear to support stricter mileage targets. A Washington Post-Kaiser Family Foundation released in September found that 66 percent of Americans oppose Trump’s plan to freeze fuel efficiency standards rather than enforce the Obama administration’s targets for 2025.
A nearly identical 67 percent majority said they support state governments setting stricter fuel efficiency targets than the federal government. Among Californians, the survey found that 68 percent oppose Trump’s relaxation of mileage standards, while 61 percent support California’s stricter standards.
Currently, 13 states and the District of Columbia have vowed to adhere to California’s standards if they diverge from the federal government’s. The move could plunge automakers into a prolonged period of uncertainty, and create turmoil in the nation’s auto market.