Last mentioned: Mar 20, 2026
The Trump administration EPA officially revokes the 2009 scientific finding.
Public health and environmental groups file the first lawsuit against the repeal.
24 states and 10 cities file a major challenge in the D.C. Circuit Court of Appeals.
State Coalition Lawsuit
24 states and 10 cities file a major challenge in the D.C. Circuit Court.
First Legal Challenge
Public health and environmental groups file the first lawsuit against the repeal.
EPA Finalizes Repeal
The Trump administration EPA finalizes the rule revoking the 2009 finding.
Endangerment Finding Issued
The EPA officially finds that greenhouse gases threaten public health and welfare.
Endangerment Finding Issued
The EPA determines greenhouse gases threaten public health, triggering Clean Air Act mandates.
A coalition of 24 states and 10 cities has filed a lawsuit against the EPA to block the repeal of the 2009 endangerment finding. The legal challenge seeks to restore the scientific foundation that allows the federal government to regulate greenhouse gas emissions under the Clean Air Act.
A coalition of 24 states and 10 cities has filed a lawsuit against the EPA to challenge the repeal of the 2009 endangerment finding, which identified greenhouse gases as a public health threat. This legal battle represents a critical juncture for U.S. environmental policy, as the repeal threatens the foundational legal basis for regulating emissions from vehicles and power plants.