The U.S. Environmental Protection Agency is preparing to reverse its 2009 “Endangerment Finding,” a regulatory determination that greenhouse gas emissions from motor vehicles, buildings, power plants, and other sources “endanger public health and welfare.” That endangerment pronouncement, made under Section 202(a) of the Clean Air Act, created the legal justification for many of the sweeping climate regulations that have touched every major sector of the American economy.

The news that the EPA submitted a proposed rule to the White House Office of Management and Budget on June 30 entitled “Greenhouse Gas Endangerment Finding and Motor Vehicle Reconsideration Rule,” (although the text of the rule is not yet provided) to reverse this finding should come as a surprise to no one. In fact, the agency announced on March 12 that it would do just this, initiate a formal reconsideration of the Endangerment Finding.

This represents a dramatic turning point in U.S. environmental law, not a dismantling of protections as some suggest, but rather the beginning of a slow process like turning a ship at sea to bring regulatory science back into alignment with the laws of our nation as passed by Congress. Whatever one’s partisan view, or not, this is a big deal that will impact nearly every business and household. As a single act, it is the biggest environmental matter the Trump administration has undertaken.

What is the Endangerment Finding?

At the heart of this reconsideration lies a fundamental legal precept: regulations derive authority from statutes and therefore cannot contradict or exceed the statutes from which they derive authority.

The Endangerment Finding was issued by EPA in response to the Supreme Court’s 2007 decision in Massachusetts v. EPA, which held that greenhouse gases are “air pollutants” under the Clean Air Act and that the EPA must regulate them if it finds they endanger public health or welfare. Not to be ignored, that Supreme Court decision grew out of a 1999 “petition for rulemaking” in which 19 private organizations called on EPA to regulate GHG emissions from new motor vehicles (i.e., it did not arise from an act of Congress).

But that judicial command was narrow. The Court did not require regulation; it required a reasoned determination. In 2009, the Obama era EPA made such a determination, including going far beyond only new motor vehicles. In 2016 and again in 2022, the agency reaffirmed it. From that flowed the entire new body of regulation that is the regulation of GHG emissions, which has grown so fast and large as to all but suck the air out of the room for other environmental protections.

The current EPA is now reassessing the legal underpinnings of that determination in light of updated judicial interpretations, technological advances, and economic shifts.

This is precisely how administrative law is supposed to work. Agencies are not frozen in amber; they are accountable to new evidence, new jurisprudence (such as the Supreme Court’s recent decision in Loper Bright Enterprises v. Raimondo limiting deference to agency interpretations), and evolving executive branch will. Reconsideration, especially after a transparent public notice and comment process, upholds the rule of law.

Scientific Transparency Should Be Encouraged, Not Feared

Contrary to alarmist media narratives, reconsideration does not equal denial of climate change. It signals an appropriate skepticism toward regulatory overreach and toward an aging scientific consensus that may no longer reflect current priorities.

Much of the concern over the proposed reversal of the Endangerment Finding centers around science, but law and science are not synonymous. The Clean Air Act requires a scientific judgment about endangerment, yes, but not a monolithic or unchanging one.

By way of example, the 2009 Endangerment Finding considered six GHGs collectively, rather than individually. EPA’s current leadership has raised questions about whether this aggregate approach was justified. That is a valid scientific and legal question. Moreover, the agency is considering the vast technological developments that have emerged over the past decade: advances in carbon capture, zero emissions transport, decentralized power generation, and atmospheric modeling, all of which may affect the risk calculus surrounding GHG emissions.

It is intellectually dishonest to suggest that asking hard questions about evolving science and changing law undermines environmental protection. Quite the opposite. A regulatory regime that is responsive to updated information, rather than beholden to policy goals fixed in a different era, is more resilient and better suited to serve the public interest.

Courts Have Left the Door Open for Change

Legal critics of the proposed reversal have already pointed to Coalition for Responsible Regulation v. EPA, in which the D.C. Circuit upheld the 2009 Endangerment Finding. But as the court made clear, its review was grounded in the record then before the agency. The law does not bind the EPA to one path forever. What it requires is consistency and rationality. If the agency believes, after reasoned analysis and public comment, that the previous findings are flawed or overstated, it has both the authority and the responsibility to correct course.

Moreover, the 2024 Supreme Court decision in Loper Bright explicitly overruled the Chevron doctrine, removing the judicial obligation to defer to agency interpretations of ambiguous statutes. Courts will now review the EPA’s statutory interpretation de novo. That legal sea change alone justifies a fresh look at the Clean Air Act’s applicability to climate regulation (cf., when the Clean Air Act was approved by Congress in 1970, we were not yet stringing the words “climate change” together).

This Is Not Deregulation – It’s Re – Regulation

Let’s be clear: reversing the Endangerment Finding will not, by itself, eliminate any existing climate rule. Each regulation, whether for vehicles, power plants, or buildings, has its own legal and scientific basis and would need to be reviewed independently (.. remember the original petition for rulemaking was only about new motor vehicles). EPA has announced that it intends to do just that.

This reconsideration is not an attack on the environment. It is an affirmation that sweeping federal regulations must be justified by sound science and grounded in clear statutory authority. Americans deserve an environmental policy that is legally durable, economically sound, and scientifically current.

Again, this is not a repeal by fiat; this is a rulemaking in accordance with the Administrative Procedure Act and Section 307 of the Clean Air Act. And to suggest otherwise is to ignore the rule of law.

A Call for Constructive Engagement

The upcoming public notice and comment period is a critical opportunity for all stakeholders, environmental groups, energy producers, scientists, state governments, and individual citizens to make their voices heard. That process will shape the final rule and ensure its legitimacy in both the court of law and the court of public opinion.

Key to all of this is that Congress has never acted on GHG emissions. If lawmakers disagree with EPA’s new direction, they can codify the Endangerment Finding or direct EPA through statute. That is how our constitutional system works: the legislative branch writes the laws; the executive implements them; and the judiciary ensures both stay within their bounds.

Conclusion

EPA’s reconsideration of the Endangerment Finding is not an attack on science; it is a reaffirmation of law. It invites a long overdue national dialogue about how best to address climate change within the constitutional structure of our republic and in the context of other environmental matters.

What is certain is that the conversation over what will be the biggest environmental issue of the year is beginning in earnest. We urge all that it be guided not by fear or partisanship, but by facts and law, seeking to protect human health and the environment.

If you’d like to participate in the public comment period when the EPA’s proposed rule is published, or if your business may be particularly affected by changes in the federal climate regulatory framework, our law firm can advise you on your options and help prepare tailored legal and policy responses.