A coalition of Democratic-led states and cities sued the Trump administration's Environmental Protection Agency on Thursday over its repeal of Biden-era rules requiring reductions in greenhouse gas emissions from power plants.

The lawsuit, filed in the U.S. Court of Appeals for the District of Columbia Circuit, targets the agency's decision last month to revoke the 2024 Carbon Pollution Standards. Those standards mandated that many coal- and gas-fired plants install carbon capture technology or meet strict emission targets.

New York Attorney General Letitia James led the effort, joined by attorneys general from states including California, Colorado, Illinois, Michigan, and others, along with Pennsylvania Governor Josh Shapiro, the District of Columbia, and cities such as New York City, Chicago, and Denver. The coalition argues the EPA failed to consider reasonable alternatives or account for health and climate impacts before repealing the limits.

Power plants represent the second-largest source of U.S. greenhouse gas emissions after transportation and account for about one-quarter of the nation's carbon dioxide output. The repealed standards aimed to cut emissions from both existing and new facilities.

The Trump EPA has framed the repeal as necessary to eliminate costly regulatory burdens that raise energy prices and hinder domestic fossil fuel production. Administration officials have pointed to legal precedents limiting agency authority under the Clean Air Act.

This action follows earlier legal challenges by states against the EPA's revocation of the 2009 endangerment finding, which underpinned broader climate regulations. Critics of the original rules contend they represented federal overreach that prioritized environmental mandates over economic growth and affordable energy for American families and businesses.

The petition asks the court to vacate the repeal and restore the emission standards. The EPA has not yet responded to the latest filing.