What is the endangerment finding and why does Lee Zeldin want to reverse it?

Lee Zeldin, administrator of the Environmental Protection Agency, has publicly declared his intention to kick away the central pillar of the federal government’s entire climate-mitigation strategy.

On July 29, he formally proposed to do it. The stakes are enormous and affect the entire economy. The provocative move is certain to provoke pushback and tee up court fights that could last for years.

That central pillar—or “holy grail” of climate strategy, as some call it —is the EPA’s “endangerment finding” of 2009. Zeldin’s EPA wants to revoke it.  The consequences of such a revocation, should it be allowed to happen, would be widespread across a range of activities.

The roots of that finding go back to a controversial 5-4 U.S. Supreme Court decision, Massachusetts v. EPA, when the court ruled in 2007 that heat-trapping greenhouse gases—not just carbon dioxide, but nitrous oxide, sulfur hexafluoride and other hydrocarbons — could be classified as “air pollutants” under the 1970 Clean Air Act. Justices John Roberts, Samuel Alito and Clarence Thomas—all of whom are members of today’s court—dissented from Massachusetts v. EPA, along with the late Justice Antonin Scalia.

Before that ruling, “air pollutants” under the CAA meant substances had to directly harm human health by exposure. In Massachusetts v EPA, the court expanded that definition by ruling heat-trapping gases were “air pollutants” through their greenhouse effects. Furthermore, the court said EPA could not decline to regulate them. Under the administration of President Barack Obama, the 2009 endangerment finding followed. Since it was a scientific finding, not itself a regulation, courts couldn’t directly overturn it.

Since virtually any kind of economic activity produces carbon emissions, the 2007 case and 2009 endangerment finding drastically expanded EPA’s authority to regulate broad swaths of the economy.  The finding’s revocation, if allowed, would drastically reduce that regulatory authority.  It would remove the legal justification for electric vehicle mandates, carbon markets, alternative fuels subsidies, and many other activities in which tens of billions of dollars have been invested.

Zeldin released the agency’s proposal to rescind the finding at an auto dealership in Indiana, calling it “the largest deregulatory action in history.” On the EPA’s website, the agency claims that the revocation “would undo the underpinning of $1 trillion in costly regulations [and] save more than $54 billion annually.”

“With this proposal, the Trump EPA is proposing to end 16 years of uncertainty for automakers and American consumers,” said Zeldin, “In our work so far, many stakeholders have told me that the Obama and Biden EPAs twisted the law, ignored precedent, and warped science to achieve their preferred ends and stick American families with hundreds of billions of dollars in hidden taxes every single year. We heard loud and clear the concern that EPA’s GHG emissions standards themselves, not carbon dioxide, which the finding never assessed independently, was the real threat to Americans’ livelihoods. If finalized, rescinding the Endangerment Finding and resulting regulations would end $1 trillion or more in hidden taxes on American businesses and families.”

Legal obstacles and next steps

Whether or not the revocation will take place or be allowed to stand is a very open question. The EPA must instead go through a rule-making process, citing conflicting scientific findings to justify its decision. On the same day, July 29, the Energy Department released a companion report challenging the scientific consensus behind the endangerment finding-which means behind much of climate science.

The EPA said, “Much has changed since the 2009 Endangerment Finding was issued, including new scientific and technological developments that warrant review. Additionally, major Supreme Court decisions in the intervening years, including Loper Bright Enterprises v. Raimondo, West Virginia v. EPA, Michigan v. EPA, and Utility Air Regulatory Group v. EPA, have significantly clarified the scope of EPA’s authority under the CAA. The decisions emphasized that major policy determinations must be made by Congress, not by administrative agencies.”

This last sentence refers to what legal scholars call the “major questions doctrine,” according to which major policy decisions that affect national life have to be made by Congress, not regulatory agencies or courts. In a number of recent decisions cited by EPA, notably Loper Bright, the current Supreme Court has clawed back regulatory authority formerly delegated to federal agencies and the courts.

The finding currently underpins the regulation of vehicle emissions, renewable fuel mandates and power plants. Revoking the finding would jeopardize those regulations and is sure to lead to legal challenges from individual states, environmental groups and industries seeking to keep the status quo. Lawsuits could number in the dozens or hundreds, although they are likely to be consolidated, as were lawsuits in the back-and-forth legal battles over the highly contested but less sweeping “waters of the U.S.” definition. That definition was changed because of lawsuits and counter-suits across several administrations and was suspended for seven to nine years of its existence since 2015, depending on the state. 

Given the scope of the interests at stake in the endangerment finding, and the tens of billions of dollars that have already been invested under its regime, court fights could extend for many years, long outlasting the Trump administration itself.

Despite some websites and publications claiming otherwise, the Supreme Court has never considered or upheld the endangerment finding on its merits. However, it has twice declined to hear challenges to it from lower courts, in 2012 and 2022. That refusal was seized on by its defenders.

Vehicle mandates

“If finalized, this proposal would remove all greenhouse gas standards for light-, medium- and heavy-duty vehicles and heavy-duty engines, starting with EPA’s first greenhouse gas set in 2010 for light-duty vehicles and those set in 2011 for medium-duty vehicles and heavy-duty vehicles and engines—which includes off-cycle credits like the much hated start-stop feature on most new cars,” according to the EPA site.

If the EPA declares that it no longer has authority to regulate or limit higher-octane pure petroleum gasoline or airplane fuel, what happens to renewable fuels from corn, soybeans and other crops? That question is leaving many farm and ag organizations silent on their stance on the revocation. Ethanol from corn and renewable fuels from soybeans, corn and a variety of oilseed crops have become increasingly important to ag producers, a major bloc of President Trump’s supporters.

Many commentators wonder whether society has gone so far in emissions reduction globally that the rollback may not be able to succeed, even in the unlikely event it prevails in court. Large American companies have to operate overseas in countries that show no sign of their own pullbacks of environmental regulations. Entire industries have grown up around emissions reduction and carbon mitigation. And the farm sector has relied on domestic demand for alternative fuels to partly compensate for lower commodity prices and trade uncertainty.

David Murray can be reached at [email protected].