In summary

California plays a central role setting auto rules and has a responsibility to lead the world’s fight against auto pollution. President Trump wants to revoke that unique authority. California Air Resources Board Chairwoman Mary Nichols must defend it.

By Dan Becker and James Gerstenzang

Dan Becker directs the Safe Climate Campaign in Washington, D.C., James Gerstenzang is the campaign’s editorial director,

President Donald Trump has slammed the brakes on the joint U.S.-California program to slash auto emissions and double gas mileage.

It’s up to Mary Nichols and the California Air Resources Board that she chairs to fight for the clean-car plan—the biggest single step any nation has taken against global warming.

The Trump rollback would halt gas mileage and emissions improvements. As a result, the fleet of new cars and trucks sold in 2025 would average just 29 miles per gallon in real-world driving, rather than 36 mpg, the equivalent of roughly 50 mpg in test conditions.

Nichols has said the state would “take whatever actions are needed to protect our people.”

The board can do that by:

  • Resisting compromising with the auto industry, which is lobbying for opaque loopholes to avoid incurring consumers’ ire by parroting Trump’s outright attack on fuel efficiency.
  • Thwarting automakers’ desire for weak post-2025 standards by putting vehicles on a strict low-emission regimen.

California plays a central role setting auto rules and has a responsibility to lead the world’s fight against auto pollution. Under the national Clean Air Act, the state has the right to set air pollution standards that are tougher than those set by the U.S. Environmental Protection Agency, a response to its historic air pollution.

Trump wants to revoke that unique authority. Nichols must defend it.

Consider its impact: A dozen other states—40 percent of the nation’s auto market—follow California’s emissions leadership. Because no automaker wants to make two sets of vehicles to meet two sets of standards, the industry accepted the Obama administration rules, which were largely built on California law.

The rollback has been the industry’s Job One ever since the chief executives of Ford, General Motors and Fiat Chrysler asked Trump to gut the rules four days after he was inaugurated.

They didn’t check whether he had disconnected the brakes before they helped him push the standards down the hill.

Facing blowback because the weaker standards would drive up pollution and raise pump costs, auto company executives are seeking loopholes, which they euphemistically call “flexibilities.” In essence, they seek to manufacture increasing numbers of polluting SUVs and other trucks.

The California Air Resources Board has begun considering rules for 2026 and beyond. It should start by eliminating a dodgy device exploited by automakers for years. The provision subjects SUVs, pickups, and minivans to weaker emissions rules than cars, allowing automakers to use outdated technology under the hood.

It’s an escape hatch from clean-car rules big enough to drive a Hummer through. No wonder the industry is abandoning car production in favor of fat-markup gas-guzzling trucks.

Some people need trucks for work. But California should couple tougher standards with incentives that encourage other motorists to buy the cleanest vehicles that meet their needs.

Allowing hybrids to use HOV lanes and offering state rebates encourages consumers to buy gas-electric vehicles. Similarly, the state should consider lowering registration fees, providing tax credits and providing access to more convenient parking for fuel-efficient vehicles.

Without taking a big bite out of auto pollution, California can’t get close to targets written into state law of cutting total greenhouse gas emissions to 40 percent below their 1990 level by 2030.

Plug-in electric vehicles are playing an essential role in meeting this challenge. But relying on zero-emission vehicles won’t cut pollution enough.

From wellhead to tailpipe, each gallon of gasoline we burn pumps 25 pounds of carbon dioxide into the atmosphere. So we must make steep cuts in emissions from gasoline-powered vehicles.

If fully enforced, the Obama rules would keep six billion tons of carbon dioxide out of the atmosphere, while saving 12 billion barrels of oil and $1 trillion at the pump. Trump’s proposal will put Californians at risk from pollution and more global warming-fueled wildfires, drought, and rising sea levels.

Mary Nichols has wrestled for decades with the automakers and their political allies to protect the public. What better way to cap her career than by ensuring that generations to come will be able to enjoy clean air and a safe climate

We want to hear from you

Want to submit a guest commentary or reaction to an article we wrote? You can find our submission guidelines here. Please contact CalMatters with any commentary questions: