Why It Matters
The Environmental Protection Agency rescinded its 2009 greenhouse gas endangerment finding and repealed federal greenhouse gas emission standards for highway vehicles, reversing the legal foundation for more than 15 years of federal vehicle climate regulations and setting up new legal and congressional fights over the agency’s authority under the Clean Air Act.
A recent CRS report examines EPA’s Feb. 12 decision to rescind its landmark 2009 endangerment finding and eliminate subsequent federal greenhouse gas emission standards for light-, medium- and heavy-duty highway vehicles and engines. The action reverses the regulatory framework EPA had used since 2010 to limit vehicle greenhouse gas emissions.
The 2009 Endangerment Finding determined that six greenhouse gases in the atmosphere threaten public health and welfare and that emissions from new motor vehicles and engines contribute to that pollution. EPA identified risks including increased temperatures, worsening air quality, extreme weather and effects on water resources, agriculture and ecosystems. The finding itself did not impose regulatory requirements but served as the prerequisite for EPA’s subsequent vehicle greenhouse gas standards.
The rescission eliminates future compliance obligations associated with EPA’s greenhouse gas standards, including measurement, reporting and certification requirements. EPA estimates the action will reduce vehicle costs by more than $1.3 trillion, though that figure reflects the agency’s own regulatory analysis. The action does not eliminate federal fuel economy standards administered separately by the National Highway Traffic Safety Administration or EPA regulations covering traditional air pollutants and air toxics.
Transportation has been the largest source of U.S. greenhouse gas emissions in recent years, with highway vehicles accounting for the majority of transportation-sector emissions. The decision also comes after Congress partially unwound climate provisions of the Inflation Reduction Act through P.L. 119-21.
The Big Picture
The legal dispute stretches back to Massachusetts v. EPA. In 2007, the Supreme Court ruled 5-4 that greenhouse gases qualify as “air pollutants” under the Clean Air Act and rejected EPA’s position that it lacked authority to regulate greenhouse gases from new motor vehicles. The Court directed EPA to determine whether those emissions cause or contribute to air pollution that may reasonably be anticipated to endanger public health or welfare or provide a permissible statutory reason for declining to make that determination. EPA subsequently issued the 2009 Endangerment Finding.
EPA promulgated its first greenhouse gas emission standards for passenger cars and light-duty trucks in 2010 and standards for medium- and heavy-duty vehicles and engines beginning in 2011. Subsequent administrations strengthened or revised those requirements through additional rulemakings.
In rescinding the finding, EPA concluded that Section 202(a) of the Clean Air Act does not authorize the agency to regulate motor vehicle emissions for the purpose of addressing global climate change. EPA also argued that vehicle greenhouse gas regulations cannot materially affect the public health and welfare concerns associated with global climate change and that Congress did not intend Section 202(a) to confer such broad regulatory authority.
The agency’s legal reasoning relies in part on Supreme Court decisions issued after Massachusetts v. EPA, including Utility Air Regulatory Group v. EPA and West Virginia v. EPA, as well as the court’s development of the major questions doctrine and its decision in Loper Bright Enterprises v. Raimondo ending Chevron deference. EPA maintains that Massachusetts established that greenhouse gases qualify as air pollutants but did not require the agency to issue the 2009 Endangerment Finding.
The rescission’s regulatory impact analysis also differs from previous EPA analyses. According to CRS, EPA did not monetize certain health and climate effects, citing substantial uncertainty. Even without those monetized benefits, three of the four scenarios analyzed by EPA produced positive net benefits from the prior vehicle standards, ranging from roughly $180 billion to $920 billion.
The Bottom Line
Congress has several options for responding to the rescission. Lawmakers could seek to overturn the rule under the Congressional Review Act, amend the Clean Air Act to clarify EPA’s authority over greenhouse gases or use appropriations legislation to affect implementation.
The rescission also shifts the dispute back to the courts. Challenges to EPA’s interpretation of Section 202(a) could determine how Massachusetts v. EPA applies in light of subsequent Supreme Court decisions limiting agency authority. The outcome could shape not only federal vehicle emission standards but the broader boundaries of EPA’s authority to address climate change under the Clean Air Act.
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