Twenty-one state attorneys general, led by New York AG Letitia James, filed a federal petition for review seeking to overturn the U.S. EPA's September 2025 repeal of greenhouse gas standards for fossil fuel-fired power plants.

The coalition's challenge targets the rollback of 2024 emissions limits covering existing coal and new natural gas units, including carbon capture and storage (CCS) requirements that had begun shaping project pipelines across the U.S. generation sector. The coalition also filed a separate notice of intent to sue EPA over its alleged failure to fully regulate existing gas-fired plants under the Clean Air Act.

Which rules did EPA repeal?

The September 2025 action stripped most provisions of the 2024 power plant GHG rule, eliminating:

• Emissions guidelines for existing fossil fuel-fired plants
• CCS requirements for modified coal plants
• CCS requirements for new natural gas baseload units

EPA simultaneously proposed rescinding the 2015 Greenhouse Gas Findings for Fossil Fuel-Fired Power Plants, the endangerment finding underpinning any future GHG regulation under Clean Air Act Section 111. Stripping that finding would constrain EPA's ability to reinstate comparable limits under a future administration.

What's the legal theory?

The petition argues EPA acted "arbitrarily and capriciously" by scrapping the standards without weighing reasonable alternatives or quantifying the climate and health costs of additional emissions. New York AG James framed the lawsuit as a defense of federal climate authority.

"This administration's insistence on giving the nation's biggest polluters a free pass will set our country back decades in the fight against climate change," James said. "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."

Which jurisdictions joined?

Alongside New York, attorneys general from 20 other states joined the petition, plus the District of Columbia. The plaintiffs include:

Arizona, California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Jersey, New Mexico, North Carolina, Oregon, Rhode Island, Vermont, Washington, Wisconsin.

The Governor of Pennsylvania, the Mayors of New York City and Chicago, and the City and County of Denver are also named plaintiffs.

How does the litigation sit in the regulatory timeline?

The 2015 Clean Power Plan, issued under President Obama, used Clean Air Act Section 111 to cap CO2 emissions and push generation away from coal. The U.S. Supreme Court struck down that generation-shifting framework in West Virginia v. EPA in 2022.

The Biden EPA responded with the 2024 rule, moving from sector-wide caps to plant-level emissions controls and binding CCS mandates for modified coal units and new gas-fired baseload capacity. The Trump administration's September 2025 repeal walked back that plant-level structure. The petition asks the court to restore it.

What does this mean for circular materials?

The 2024 rule's CCS mandates fed the early commercial market for CO2 utilization, a feedstock stream with growing ties to cement decarbonization, synthetic aggregate production and chemical recycling of waste plastics. A successful challenge does not retroactively void permits already secured by CCS developers but would harden regulatory uncertainty for projects still in planning.

Coal ash recycling, a mature circular stream moving millions of tons annually into concrete, wallboard and structural fill, runs in parallel: power plant retirements driven by GHG compliance would have accelerated beneficial reuse demand for that material.

EPA Administrator Lee Zeldin telegraphed the rollback in 2025, arguing that power plant GHG emissions "do not contribute significantly to dangerous air pollution" under the Clean Air Act.

What comes next?

The petition for review lands in federal appellate court. The court's handling of the 2015 endangerment finding withdrawal, and any remand to EPA for further cost-benefit analysis, will set the regulatory ceiling for U.S. power sector emissions through 2030.

A separate notice of intent to sue over existing gas-fired plants opens a second litigation track. That case could run on a different timeline and force EPA to address Section 111 obligations for the largest fleet of new U.S. generation capacity regardless of the 2024 rule's fate.