Donald Trump's EPA plans to repeal 2009 climate change endangerment ruling

When it proposed to repeal the finding last year, the EPA also proposed to repeal all climate regulations for cars and trucks along with it. The final repeal is expected to do the same — a massive regulatory rollback in and of itself, as transportation is the largest source of U.S. emissions. Reached for comment, an EPA spokesperson noted that without the endangerment finding, the “EPA would lack statutory authority under Section 202(a) of the Clean Air Act (CAA) to prescribe standards for certain motor vehicle emissions.”

The Clean Air Act requires the EPA administrator to regulate emissions from vehicles of any pollutant that “in his judgment cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare.” The Supreme Court ruled in 2007 that planet-warming emissions fall under the law’s definition of air pollutants and should be regulated if they’re found to be a threat to public health.