Biden’s exhaust emission rules on shakier ground after Supreme Court ruling

By Lisa Baertlein

(Reuters) – A U.S. Supreme Court ruling that limits federal regulatory powers to interpret ambiguous laws could undermine President Joe Biden’s effort to reduce tailpipe emissions from the nation’s vehicle fleet, two environmental lawyers told Reuters.

In a ruling released Friday, the justices ruled 6-3 to overturn a 1984 precedent known as “Chevron deference” that required judges to defer to federal agencies’ reasonable interpretations of U.S. laws deemed ambiguous, like the Clean Air Act.

While the ruling by the nation’s highest court could make it more difficult for federal agencies to defend strict regulations around a range of environmental, health and other laws, lawyers told Reuters that Biden’s efforts to reduce greenhouse gas emissions greenhouse gas emissions (GHG) emissions from planet-warming cars and trucks could be particularly vulnerable.

This is because the rules target mobile sources of greenhouse gases rather than stationary sources such as power plants, although environmental laws are ambiguous about whether regulators have a mandate to do so.

“There have been long-standing debates about whether and to what extent the (U.S. Environmental Protection Agency) has the authority to regulate emissions from mobile sources,” said Sherry Jackman, environmental litigator and compliance counsel at Greenberg Glusker in Los Angeles.

Transportation accounts for about a quarter of U.S. carbon output and is a crucial target for the Biden administration as it seeks to decarbonize the economy to combat climate change.

David Pettit, senior climate and energy attorney at the Natural Resources Defense Council, predicted that critics would use the Chevron decision to launch new attacks on vehicle rules that regulate greenhouse gases.

“One of the ways the industry, particularly the oil industry, will try to use the Chevron ruling is to say that the EPA did not have the legal ability to rule that the Clean Air Act covers GHG emissions from mobile sources because No, I don’t say that in the Clean Air Act,” Pettit said.

An EPA spokesperson did not immediately respond to a request for comment.

Environmental groups said the EPA’s other historic climate rules, including its rule requiring emissions cuts from power plants, appeared to be on more solid footing, and that the agency in recent years has sought to write regulations without relying on Chevron’s deference.

Interest groups, including automakers, oil companies, corn and soybean producers, have already launched a myriad of administrative and legal challenges to the Biden administration’s plan to reduce vehicle emissions, arguing that the rules would force everything from passenger cars to 18-wheel vehicles becoming electric.

They have been successful in watering down the EPA’s tailpipe emissions rules in the past and some of their challenges are still pending and may be subject to the Supreme Court’s Chevron ruling.

(Editing by Richard Valdmanis and Mark Porter)