US States, Cities Sue Trump Administration Over Climate Regulations

Got story updates? Submit your updates here. ›

A group of three dozen states, cities, and counties led by New York and California have filed a lawsuit against the Trump administration, challenging its decision to revoke the scientific finding that forms the basis of U.S. climate regulations. The legal challenge also targets the EPA's move to repeal tailpipe rules limiting greenhouse gas emissions from cars and trucks.

Why it matters

This lawsuit represents a major pushback from state and local governments against the Trump administration's efforts to roll back federal climate policies. The outcome could have significant implications for the future of U.S. climate regulations and the country's ability to address global warming.

The details

The lawsuit was filed in the U.S. Court of Appeals for the District of Columbia and includes the states of Michigan, Connecticut, and Virginia, as well as the cities of New York, Boston, Chicago, Denver, and Los Angeles. It follows an earlier challenge filed by a coalition of environmental groups against the EPA's decision to repeal the tailpipe emissions rules.

• The lawsuit was filed on March 18, 2026.
• The EPA announced its decision to repeal the tailpipe emissions rules in February 2026.

What’s next

The court will hear arguments and make a ruling on the lawsuit, which could have significant implications for the future of U.S. climate regulations.