A coalition of states and cities has filed suit against the U.S. Environmental Protection Agency after the agency, under the Trump administration, eliminated the rule that limits greenhouse gas emissions from power plants.

The challenge, filed in federal court, takes aim at the EPA's repeal of the emissions rule that regulated carbon output from the utility sector — the country's second-largest source of industrial emissions and a decisive factor in demand dynamics for recycled metals, recovered materials and energy-intensive reprocessing capacity.

The plaintiffs argue the agency's withdrawal of the regulation exceeds its authority. Under the Clean Air Act, the EPA is obligated to regulate hazardous and criteria pollutants, and the states contend that scrapping the emissions rule abandons a statutory duty that courts have previously affirmed. The agency, in announcing the repeal, has defended the move as easing compliance burdens on generators.

For the materials and circularity sectors, the stakes are structural. Coal-fired generation remains among the most emissions-intensive inputs to the U.S. grid, and the repealed rule was the principal federal mechanism pushing utilities toward retirements, fuel switching and lower-carbon procurement. Repeal extends the operating horizon of older units; litigation over that reversal now determines whether those timelines hold.

The suit marks the opening of a legal contest that will run through the federal courts for months, potentially years. State attorneys general have successfully used litigation to slow or reverse prior regulatory rollbacks, and the same playbook applies here: seek an injunction, force the agency to justify the repeal on the record, and push the question toward appellate review.

The EPA, for its part, will defend the repeal as a lawful exercise of administrative discretion. Agency leadership has argued the prior rule imposed costs on generators without commensurate benefits — a contention the plaintiffs reject and that the court will now test against the administrative record.

The outcome carries consequences beyond the utility sector. Grid carbon intensity factors into the emissions accounting that increasingly shapes procurement decisions, state recycling mandates and extended producer responsibility frameworks. If the repeal stands, the federal emissions constraint on power plants disappears, shifting the regulatory burden to state-level programs and the courts. If the plaintiffs prevail, the rule — or some version of it — returns to enforcement.

What happens next turns on the briefing schedule. The court must first decide whether to stay the repeal while the case proceeds. That injunction ruling, expected in the coming months, will determine whether the emissions limits lapse in practice during the litigation or remain in force until the merits are heard. The decision on that motion is the milestone to watch.