Last mentioned: Mar 20, 2026
Multi-State Lawsuit Filed
A coalition of 23 states and 14 cities files a legal challenge in the U.S. Court of Appeals.
Multi-State Lawsuit Filed
A coalition of 23 states and 14 cities sues the EPA in the D.C. Circuit Court of Appeals.
EPA Revokes Finding
The Trump administration formally terminates the 2009 endangerment finding.
Trump Revokes Finding
The Trump administration formally terminates the 2009 conclusion to halt climate regulations.
Vehicle Standards Implemented
Federal rules limiting greenhouse gas tailpipe emissions for 2012-2027 models take effect.
Endangerment Finding Issued
The EPA under the Obama administration officially finds that greenhouse gases threaten public health.
Endangerment Finding Issued
The EPA under President Obama officially declares greenhouse gases a threat to public health.
A coalition of 23 states and 14 cities has filed a lawsuit against the EPA to overturn the Trump administration's repeal of the 2009 endangerment finding. The legal challenge seeks to restore the scientific foundation that mandates federal regulation of greenhouse gas emissions under the Clean Air Act.
A coalition of 23 states and 14 cities has filed a major lawsuit against the EPA to block the Trump administration's repeal of the 2009 endangerment finding. The legal challenge argues that the revocation violates the Clean Air Act and ignores established climate science to benefit the fossil fuel industry.