The Trump administration and the Environmental Protection Agency have announced massive changes to the nation’s environmental policy, moving to rescind the 2009 Endangerment Finding results on which the United States of America’s current emissions regulations are based. President Trump and EPA administrator Lee Zeldin maintain that this is the single largest deregulation action in American history.
Back in 2009, EPA administrator Lisa P. Jackson signed two distinct findings related to the endangerment brought by and causes of greenhouse gases in the atmosphere. The Obama administration and the EPA moved to limit these specific gases based on the results of the Endangerment Finding study, rolling out tighter emissions regulations for new vehicle fleets and powertrains. Detractors have argued that the EPA does not possess regulatory authority, and that Congress must be involved in establishing emissions rules.
The EPA under Zeldin first proposed rescinding the findings altogether back in July 2025, and has already rolled back tailpipe emissions regulations established by his political predecessors. With this new action, Trump and Zeldin have terminated green emissions standards imposed from 2012 onward, with no plans to impose them beyond 2027. Zeldin announced that the EPA will be advising automakers to kill start-stop technology, which he referred to as the “Obama Switch” during the press conference. (It is important to note that start-stop technology has never been mandated by the government.)