Current Environmental Protection Agency (EPA) Administrator Lee Zeldin proposed a rule today to rescind 2009 rules that form the basis of greenhouse gas (GHG) emissions limitations, a move that will almost certainly lead to protracted litigation. The proposal also includes removal of GHG emission regulations for light-, medium-, and heavy-duty vehicles.
Following the Supreme Court’s decision in Massachusetts v. EPA, 549 U.S. 497 (2007) holding that greenhouse gases are an “air pollutant” subject to regulation under the Clean Air Act (CAA), the EPA promulgated a series of rules regulating GHG in compliance with the CAA’s mandate that EPA regulate air pollutants. In December 2009, the EPA administrator signed an “Endangerment Finding” providing that current and projected concentrations of six GHGs threaten the public health and welfare of current and future generations. The EPA concluded that motor-vehicle emissions of these six GHGs “contribute to the total greenhouse gas air pollution, and thus to the climate change problem, which is reasonably anticipated to endanger public health and welfare.” The finding led to a suite of rules regulating GHG. These rules were challenged by states and industry groups in a lawsuit – alleging that the agency misconstrued the CAA and otherwise acted arbitrarily and capriciously – but were ultimately upheld.
Yesterday's announcement of the EPA’s plan to rescind the Endangerment Finding is aimed at rolling back tailpipe emissions standards, and will be subject to public comment before being finalized in the coming months. The proposed rules would eliminate engine and vehicle manufacturer obligations for the measurement, control, and reporting of GHG emissions for engines and vehicles. As with other actions taken by the EPA under Zeldin, this attempt to deregulate GHG emissions is certainly to be challenged by states such as California, which has the strictest emissions standards in the nation, along with environmental groups. Public comment is open until September 21, 2025, and a hearing is scheduled to occur on August 19 and August 20, 2025.
