EPA Revisiting California Emissions Curbs, Trump Official Says

(Bloomberg) -- President Donald Trump’s Environmental Protection Agency is considering rescinding California’s permission to tackle climate change through stringent automobile pollution limits, the administration said in a US Supreme Court filing.

In a motion that asked the court to put a pending case on hold, acting US Solicitor General Sarah Harris said the EPA had decided to “reassess the basis for and soundness of” a 2022 Biden administration decision allowing the pollution curbs.

The court is currently planning to consider a preliminary question in a lawsuit over the EPA’s power to authorize the California emissions limits. At issue is whether the entities pressing the suit — including an oil industry trade group and Valero Energy Corp. units that produce biofuels — are sufficiently affected by the regulations to go to court. 

The disputed waiver let California impose its Advanced Clean Car program, which requires manufacturers to produce an increasing percentage of zero-emission vehicles through the 2025 model year. The EPA withdrew the disputed waiver in Trump’s first term, then reinstated it after Joe Biden took the White House.

Biden’s EPA later authorized California regulations that would compel the sale of zero-emission vehicles over the next decade and ultimately ban the sale of conventional, gasoline-powered cars in 2035.

The Trump administration filed similar motions Friday asking to pause three other Supreme Court cases, including two EPA clashes and a dispute over student loan repayment.

The emissions case is Diamond Alternative Energy v. EPA, 24-7.

©2025 Bloomberg L.P.