A coalition of 25 states and cities, led by New York Attorney General Letitia James, sued the EPA on Thursday, October 1, to block the Trump administration's repeal of greenhouse gas emission limits for US power plants.

The filing in the US Court of Appeals for the District of Columbia Circuit targets the agency's repeal of the 2024 Carbon Pollution Standards — the rule that required US power plants to cut greenhouse gas emissions by installing carbon capture technology.

James did not mince words about the stakes. "Dismantling these protections is a betrayal of American families, and the stakes are too high to allow this administration to once again put profits over people," she said in a statement announcing the suit.

Why does the power plant rule matter?

The material stream at issue is large. Power plants rank as the second-biggest source of US greenhouse gas emissions, behind only vehicles, and account for one-quarter of US carbon dioxide output.

The 2024 standards would have forced operators of coal- and gas-fired generation to deploy carbon capture and storage (CCS) retrofit capacity rather than continue emitting unabated. For the CCS supply chain — capture technology vendors, pipeline developers and CO2 storage site operators — the repeal removes the single largest compliance-driven demand signal in the US power sector.

What does the lawsuit argue?

The coalition, which includes California and Michigan, advances two lines of attack:

• A petition to strike down the EPA's repeal of the Carbon Pollution Standards outright.
• A notice of intent to sue over the agency's continued failure to fully regulate pollution from existing natural gas power plants.

The states argue the EPA revoked the regulations without considering "reasonable alternatives" and without factoring in the health and climate costs of allowing more pollution into the atmosphere.

What happens next?

The case now sits with the DC Circuit, the venue that has hosted virtually every major Clean Air Act challenge of the past decade. The coalition's parallel notice on existing natural gas plants opens a second regulatory front, since the EPA's obligations toward that segment remain unresolved regardless of how the repeal challenge is decided.

The court's disposition of the petition — and whether it stays the repeal pending review — will determine whether the CCS compliance mandate survives in any form during the litigation.