California can keep setting vehicle emission rules that are stricter than the federal government’s, court says

The U.S. Court of Appeals for the District of Columbia Circuit blocked an attempt by Ohio, Alabama, Texas and other Republican-led states to revoke California’s authority to set standards that are stricter than rules set by the federal government. The court ruled that the states failed to prove how California’s emissions standards would drive up costs for gas-powered vehicles in their states.

Democratic Gov. Gavin Newsom, who often touts the state’s leadership on climate policy, said the court ruling reaffirmed California’s ability to fight the public health and environmental impacts of vehicle emissions.

“The clean vehicle transition is already here – it’s where the industry is going, the major automakers support our standards, and California is hitting our goals years ahead of schedule,” he said in a statement. “We won’t stop fighting to protect our communities from pollution and the climate crisis.”

The ruling comes ahead of a presidential election in which the outcome could determine the fate of environmental regulations in California and nationwide. Then-President Donald Trump’s administration in 2019 revoked California’s ability to enforce its own emissions standards, but President Biden later restored the state’s authority. At the federal level, Biden has pledged that zero-emission vehicles will make up half of new car and truck sales in the U.S. by 2030.

In 2022, Ohio led a coalition of states in filing a petition to attempt to block California’s ability to enforce its own vehicle emissions standards, saying it violated the U.S. Constitution and infringed upon federal government authority.

Ohio Attorney General Dave Yost’s office did not respond to email and phone requests for comment on the ruling.

For decades, California has been able to seek a waiver from the U.S. Environmental Protection Agency to set its own vehicle emission regulations. These rules are tougher than the federal standards because California, the nation’s most populous state, has the most cars on the road and struggles to meet air quality standards. Other states can sign on to adopt California emission rules if they are approved by the federal government.

Challenges to California’s authority to set vehicle emissions standards date back to when George W. Bush was president in the 2000s, said Ann Carlson, an environmental law professor at the University of California, Los Angeles School of Law. Carlson — who previously served as acting administrator under the Biden administration for the National Highway Traffic Safety Administration, which sets fuel economy rules — said the federal government often follows California’s lead on vehicle emissions regulations if they end up being successful and cost-effective.

The state’s authority to set its own standards “has really kept vehicle emissions from completely stagnating,” Carlson said.

California is seeking a waiver from the federal government to ban the sale of all new gas-powered cars by 2035. Ford, Honda, Volkswagen and other major automakers already agreed to follow California vehicle emission standards. The state has also approved rules in recent years to phase out the sale of new fossil fuel-powered lawn mowers, large trucks that transport goods through ports and trains powered by diesel.