A coalition of three dozen states and local governments has filed suit challenging the Trump administration’s recent rollback of a landmark Obama-era scientific ruling, arguing that greenhouse gases pose a clear threat to public health. The legal action seeks to overturn last month’s repeal of the 2009 “endangerment finding,” a cornerstone of U.S. policy aimed at reducing emissions from cars, power plants, and other sources of planet-warming gases.

Several environmental groups also filed a similar lawsuit last month, signaling mounting opposition to the administration’s climate policies.

Trump Administration Hails Rollback as Victory

President Donald Trump touted the reversal as a major achievement, framing it as a victory over what he called the Democratic Party’s “radical” energy and climate agenda. Yet the coalition filing the lawsuit argues the move violates provisions of the Clean Air Act, which underpin federal authority to regulate greenhouse gas emissions.

Who’s Behind the Lawsuit

The petition, filed in the US Court of Appeals, represents 23 states along with 17 cities, counties, and state agencies. Notable plaintiffs include New York City, Los Angeles, San Francisco, Boston, Chicago, and the Pennsylvania Department of Environmental Protection.

New York State Attorney General Letitia James condemned the rollback, stating, “The climate crisis is here, and it is already reshaping the way we live. Instead of helping Americans face our new reality, the Trump administration has chosen denial, repealing critical protections that are foundational to the federal government’s response to climate change.”

EPA Responds

In response, the Environmental Protection Agency described the lawsuit as “clearly motivated by politics.” A spokesperson told the BBC that the agency had “carefully considered and reevaluated the legal foundation of the 2009 Endangerment Finding,” asserting that the original ruling “does not provide EPA statutory authority to prescribe motor vehicle emission standards for the purpose of addressing global climate change concerns.”

Implications for U.S. Climate Policy

The lawsuit underscores growing tension between state-level climate initiatives and federal policy under the Trump administration. With legal challenges underway, the outcome could shape the ability of states and the federal government to regulate emissions and address the escalating effects of climate change, from rising sea levels to extreme weather events.

As the court deliberates, environmental advocates warn that reversing the endangerment finding could have long-term consequences for public health and the nation’s ability to meet international climate commitments.