California’s Power to Set Auto Emissions Rules Restored

Interstate 405, the San Diego Freeway, is seen next to Los Angeles International Airport
Interstate 405, the San Diego Freeway, is seen next to Los Angeles International Airport. (Reed Saxon/Associated Press)

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WASHINGTON — The Biden administration is restoring California’s authority to set its own tailpipe pollution standards for cars, reversing a Trump administration policy and likely ushering in stricter emissions standards for new passenger vehicles nationwide.

A waiver approved March 9 by the Environmental Protection Agency allows California to set tough emissions rules for cars and SUVs and impose mandates for so-called zero-emission vehicles that do not contribute to global warming.

Reinstatement of the waiver comes as the Biden administration proposed stronger pollution regulations for new tractor-trailer rigs that would clean up smoky diesel engines and encourage new technologies during the next two decades. A proposal released March 7 by the EPA would require the industry to cut nitrogen oxide emissions by up to 90% per new truck over current standards by 2031. The emissions can cause respiratory problems in humans.

New rules would start in 2027 to limit the emissions from nearly 27 million heavy trucks and buses nationwide.


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At least 15 states and the District of Columbia have signed on to California’s vehicle standards, which are stricter than federal rules and designed to address the state’s severe air pollution problems. According to the American Lung Association, seven of the 10 U.S. cities with the worst ozone pollution are in California, along with six of the 10 most polluted cities measured by year-round particle pollution.

Former President Donald Trump’s 2019 decision to revoke California’s authority to set its own limits on auto emissions was one of his most high-profile actions to roll back environmental rules he considered overly burdensome on businesses. Regulation of vehicle emissions is central to combating climate change.

President Joe Biden has made slowing climate change a top priority of his administration and has pledged to cut greenhouse gas emissions in half by 2030. Transportation is the single largest source of planet-warming greenhouse gas emissions in the United States, making up 29% of all emissions. Within the transportation sector, passenger cars and trucks are the largest contributor, accounting for 58% of all transportation-related emissions and 17% of overall U.S. carbon emissions.


Regan with Vice President Kamala Harris March 7. (Manuel Balce Ceneta/Associated Press)

“Today we proudly reaffirm California’s longstanding authority to lead in addressing pollution from cars and trucks,” said EPA Administrator Michael Regan. “With today’s action, we reinstate an approach that for years has helped advance clean technologies and cut air pollution for people not just in California, but for the U.S. as a whole.”

The waiver reinstates California’s authority to regulate greenhouse gas emissions under the federal Clean Air Act for model years 2017 through 2025, effective immediately. The California Air Resources Board will determine how to implement and enforce the standards.

The waiver also withdraws a Trump-era regulation that blocked other states from adopting California’s standards. Collectively they represent 36% of the U.S. auto market.

Officials in California, New York and other states have been seeking reinstatement of the waiver, saying California’s strict standards have improved air quality in the state and ensured that Los Angeles and other cities are no longer shrouded by smog.

The EPA’s action “is a major victory for the environment, our economy and the health of families across the country” and comes at a pivotal moment to address climate change, said California Gov. Gavin Newsom, a Democrat. “California looks forward to partnering with the Biden administration to make a zero-emission future a reality for all Americans.”

The new bipartisan infrastructure law includes $7.5 billion for a network of new charging stations for electric cars and trucks. Fully electric vehicles, or EVs, represent just 3% of new vehicle sales in the U.S., but analysts expect that to rise rapidly in coming years. Major automakers, including General Motors and Ford, are pledging billions to develop EVs and GM has gone so far as to announce a goal of ending gasoline-fueled passenger vehicles entirely by 2035.

Biden’s sweeping environmental and social policy bill — stalled for months in the Senate — includes a $7,500 tax credit to buyers to lower the cost of electric vehicles, along with more money for EV chargers.

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The EPA in December raised vehicle mileage standards to significantly reduce greenhouse gas emissions, reversing a Trump-era rollback that loosened fuel efficiency standards.

The EPA rule raises mileage standards starting in the 2023 model year, reaching a projected industrywide target of 40 miles per gallon by 2026. The new standard is 25% higher than a rule finalized by the Trump administration and 5% higher than an earlier proposal by the Biden EPA.

Besides New York, other states that follow California’s rule include Colorado, Connecticut, Delaware, Maine, Maryland, Massachusetts, New Jersey, Oregon, Pennsylvania, Rhode Island, Vermont and Washington. Several other states are moving to adopt the California standard.

Trump’s move to revoke the state waivers split the industry, with most automakers behind him while Ford, Honda, BMW, Volkswagen and Volvo decided to go with California standards. After Biden was inaugurated, General Motors and other automakers came out in favor of California setting its own standards.

Associated Press writers Tom Krisher in Detroit and Kathleen Ronayne in Sacramento contributed to this story.