More than 20 state attorneys general and several local governments filed a petition Oct. 1 in the U.S. Court of Appeals for the D.C. Circuit challenging the EPA's September repeal of the 2024 Carbon Pollution Standards for fossil fuel-fired power plants.

New York Attorney General Letitia James is leading the coalition. The lawsuit targets the EPA's September decision to withdraw most greenhouse gas requirements for new and existing coal and natural gas plants adopted under President Joe Biden.

The plaintiffs argue the agency acted unlawfully by stripping the standards without adequately accounting for the consequences of increased pollution. They are asking the federal appeals court to overturn the repeal and restore the protections.

What did the EPA actually repeal?

The EPA's September action stripped most of the 2024 Carbon Pollution Standards, which had set greenhouse gas limits for certain new and existing coal and natural gas power plants. Those standards were the Biden administration's central tool for pushing the power sector toward carbon capture and other emissions controls.

The agency has defended the repeal as a way to reduce regulatory costs and support reliable energy supplies, projecting roughly $310 billion in savings. EPA has also proposed going further by rescinding the remaining greenhouse gas standards still on the books for the power sector.

What is at stake for utilities and generators?

The 2024 rules pushed certain coal and gas plants toward carbon capture or other emissions controls. The Trump administration has argued those requirements impose excessive costs and threaten energy affordability and reliability.

The outcome will shape compliance planning across the utility sector, particularly for operators weighing retrofits to existing coal units. Coal and natural gas producers are also tracking the case for signals on long-term federal climate policy and the cost of meeting environmental requirements.

How does this connect to EPA's broader rollback?

The lawsuit lands as the EPA pursues a parallel effort to unwind the rest of the federal framework governing power-sector greenhouse gas emissions. The agency's broader proposal would revisit the regulatory structure used for fossil fuel-fired power plants under Section 111 of the Clean Air Act.

EPA held public hearings on that broader proposal Oct. 1 and 2, the same window the states filed their petition. The two proceedings are now moving in parallel, with the D.C. Circuit weighing the September repeal while the agency finalizes its wider Section 111 rewrite.

What other legal fights are queued up?

The Oct. 1 petition is part of a larger confrontation between Democratic-led states and the Trump administration over environmental rules adopted under previous presidents. The same coalition has signaled a separate legal challenge concerning the EPA's obligations to regulate greenhouse gas emissions from existing natural gas power plants.

For state plaintiffs, the case is an effort to preserve federal limits they view as central to public health and climate policy. For the EPA, the litigation is an early test of its broader campaign to dismantle the previous administration's power-sector climate regulations.

What happens next?

The D.C. Circuit will set a briefing schedule for the petition filed Oct. 1. A ruling could arrive within 12 to 18 months, ahead of any final action on the EPA's broader Section 111 proposal. Industry compliance planning, particularly for utilities weighing carbon capture retrofits, hangs on which set of rules survives the next regulatory and judicial milestones.