EPA Eliminates Greenhouse Gas Endangerment Finding and All Subsequent Federal Vehicle Emission Standards

In announcing the repeal, EPA Administrator Lee Zeldin stated the decision follows the letter of the law, returns common sense to policy, and delivers further consumer choice to Americans, referring to the repeal as the “single largest deregulatory action in U.S. history.” In its press release, EPA contended the Obama-era finding exceeded EPA’s authority to combat air pollution and improperly pushed electric vehicle policymaking forward. 

Below, we provide background on the 2009 Endangerment Finding, discuss EPA’s rescission of the finding, and provide preliminary thoughts on policy areas likely to be impacted by the rescission.

What Was the 2009 GHG Endangerment Finding?

The 2009 Endangerment Finding originally stemmed, in part, from the US Supreme Court’s ruling in Massachusetts v. EPA. In Massachusetts, a group of private organizations along with several states and localities challenged EPA’s denial of a rulemaking petition to regulate GHGs from motor vehicles. The Court ultimately held that EPA has the statutory authority to regulate GHG emissions from new motor vehicles under Section 202(a)(1) of the Clean Air Act, finding that EPA’s denial of the rulemaking petition was arbitrary and capricious and any such denial must be grounded in the text of the statute. 

Following the ruling, EPA issued the 2009 Endangerment Finding, which was a two-part EPA determination that (1) six GHGs in the atmosphere were reasonably anticipated to endanger public health and welfare, and (2) emissions from new motor vehicles contributed to GHG pollution. Taken together, the two parts of this determination were used as the primary basis for federal regulation of sources emitting those GHGs, like motor vehicles. Since its enactment, the 2009 Endangerment Finding has served as the basis for US emissions regulations, including those governing motor vehicles, power plants, and oil and gas operations.

EPA’s Review and Rescission

In proposing the repeal last July, EPA contended that the 2009 Endangerment Finding relied on outdated science, focused on global rather than localized risk, and was overly pessimistic about temperature impacts. The draft final repeal package arrived at the Office of Management and Budget (OMB) on January 7 (for our coverage of the draft proposal, see here). Although OMB review of major rules commonly spans up to 90 days, OMB’s review was expedited, resulting in a final repeal just five weeks later.

In finalizing the repeal, EPA stated that Section 202(a) of the Clean Air Act does not authorize the agency to enact motor vehicle and engine emissions regulations — including for the purpose of addressing global climate change — and the 2009 Endangerment Finding and its regulatory progeny lacks an adequate legal basis. Therefore, in addition to rescinding the 2009 Endangerment Finding, EPA also eliminated subsequent EPA vehicle emissions compliance programs and reporting requirements that relied on the 2009 Endangerment Finding.

EPA emphasized that it believes major policy determinations, such as the 2009 Endangerment Finding, and sweeping regulations, such as the subsequent emissions programs, should be made by US Congress, not agencies, consistent with recent Supreme Court decisions like Loper Bright Enterprises v. Raimondo (for more, see here) and West Virginia v. EPA (for more, see here).

EPA further supported the 2009 Endangerment Finding’s elimination through two additional policy rationales:

• First, EPA determined that even if the United States eliminated all vehicle GHG emissions, there would be no material impact on global climate indicators through 2100, making such standards unnecessary to fulfill EPA’s core mission.
• Second, EPA stated that this deregulatory effort is aimed at prioritizing restoring affordable vehicle ownership and consumer choice by eliminating electric vehicle mandates, off-cycle credits (including the start-stop feature), and associated compliance requirements.

What Happens Next?

The elimination of the 2009 Endangerment Finding and subsequent regulations is expected to trigger extensive litigation and public debate, building on years of controversy over the scope of EPA’s authority under the Clean Air Act and the Supreme Court’s ruling in Massachusetts, which is likely to be revisited by the Supreme Court in any challenge of the Endangerment Finding’s rescission. EPA’s decision will likely factor into ongoing debates about state-specific fuel efficiency and vehicle emissions programs and into ongoing federal efforts to preempt state efforts to address climate concerns (for more on one such effort, see here).

Environmental groups have previewed challenges aimed at the repeal’s scientific premises and economic implications, warning of increased pollution risks and higher consumer costs. Although EPA’s current elimination of the 2009 Endangerment Finding and subsequent emissions programs are most directly tied to the motor vehicle program, its implications are likely to play out across EPA’s air-related programming. Put succinctly, because the 2009 Endangerment Finding served as the legal trigger for EPA’s GHG-related regulations, removing it functionally eliminates them.

The short-term consequences of the rescission are likely to be far-reaching and may include litigation and opposition from some states and non-governmental organizations.

Domestic Implications

The rescission of the 2009 Endangerment Finding and related regulations alters the regulatory landscape and is likely to increase short-term uncertainty. States including New York, Vermont, and California have all enacted state-level climate laws. While some of these laws include reporting requirements, some states have already enacted “climate Superfund” laws which permit climate-related litigation against carbon-intensive industries. States including Illinois are considering similar legislation which, on the whole, will lead — at least in the short term — to increased state attempts to implement a patchwork of legal standards.

Outside of state action, activist plaintiffs and state attorneys general are likely to pursue judicial challenges. In the past, these stakeholders have pursued theories ranging from public nuisance to investor-disclosure theories (for more on this, see here).

International Implications

The revocation of the Endangerment Finding contrasts with other recent developments in GHG regulation in other international contexts. International regulation of GHGs has recently been found by international tribunals to be required by international treaties. 

Major international decisions were made in the climate space in 2025 by courts ranging from a July International Court of Justice Advisory Opinion on the Obligations of States in Respect to Climate Change to a European Court of Human Rights decision in Greenpeace Nordic v. Norway, both of which discuss the legal obligation of states to address climate issues (for more, see here and here). International courts, including a recent decision out of the Netherlands, continue to evaluate the impacts of these decisions, frequently finding that national governments are required to address climate impacts. 

Developments for the Regulated Community to Watch

The rescission of the 2009 Endangerment Finding will likely reduce certainty in the short term federal regulatory regimes. Outside of the federal government, investors (and indeed, states) may try to require climate risk disclosures aligned with International Sustainability Standards Board standards (see here) or other global benchmarks that are unaffected by EPA’s recission of the 2009 Endangerment Finding, or to scrutinize disclosures related to GHG issues in sustainability reporting. Multinational businesses will need to monitor GHG-related legal obligations imposed by different jurisdictions. 

The firm’s Energy & Cleantech and Environmental teams are monitoring administrative changes and developments related to EPA’s recission of the 2009 Endangerment Finding. Stay tuned for further updates.