Will the EPA’s Zeldin Uphold His Agency’s Mission or Reverse the Endangerment Finding?

Among the many attacks in U.S. President Donald Trump’s Day One Executive Order on “unleashing” American (fossil) energy, is a directive to Environmental Protection Agency Administrator Lee Zeldin to reevaluate the agency’s bedrock 2009 scientific determination of the harms caused by heat-trapping emissions and submit recommendations within 30 days (i.e. this week). The “”“Endangerment Finding” establishes that heat-trapping emissions harm people and the environment, and it forms a core legal basis for the agency’s subsequent actions to set standards to limit global warming pollution from vehicles and power plants, as well as methane pollution from oil and gas operations.

The fact remains that any science-based update to the Endangerment Finding would conclusively demonstrate that the actual harms and projected risks from climate change have only grown grimmer since the 2009 endangerment finding was issued.

It’s no surprise that this anti-science, pro-fossil fuel administration wants to go after the Endangerment Finding. Of course, an honest assessment of the latest climate science will show that since 2009 the evidence has become even more compelling and dire. Climate change, driven by rising heat-trapping emissions, is already causing significant harm to people’s health and well-being and to vital ecosystems. Those harms will worsen rapidly as global warming emissions, primarily from burning fossil fuels, increase.

This blatant attempt to do an end-run around scientific evidence deserves to fail.

What Is the Endangerment Finding?

Back in 2007, the Supreme Court reached a landmark judgment in Massachusetts et al. v. Environmental Protection Agency et al. establishing that heat-trapping emissions (or greenhouse gas emissions) are air pollutants covered by the Clean Air Act. The court further mandated that, under the Clean Air Act, the EPA must set protective standards for global warming pollutants if the agency found them to be harmful to human health and welfare.

The 2007 case was brought by petitioners (which included several state attorney generals and NGOs, including the Union of Concerned Scientists) in the context of greenhouse gas emissions from new motor vehicles.

The EPA subsequently undertook an extensive process, including hearings and a public comment period, and concluded that a vast body of scientific evidence showed that heat-trapping pollutants do indeed harm public health and welfare and that motor vehicles contribute to that pollution.

In 2009, the agency issued the Endangerment and Cause or Contribute Findings for Greenhouse Gases, summarized below:

• Endangerment Finding: The administrator finds that the current and projected concentrations of the six key well-mixed greenhouse gases—carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF₆)—in the atmosphere threaten the public health and welfare of current and future generations.
• Cause or Contribute Finding: The administrator finds that the combined emissions of these well-mixed greenhouse gases from new motor vehicles and new motor vehicle engines contribute to the greenhouse gas pollution that threatens public health and welfare.

The findings have subsequently been extended to other major sources of heat-trapping emissions, including power plants and oil and gas operations, and have been upheld in court.

For more on the legal and political twists and turns in the history of the Endangerment Finding, please check out this blogpost: “Endangered Science: Why Global Warming Emissions Are Covered by the Clean Air Act.”

What Is Zeldin Being Directed to Do?

President Trump’s Day One executive order directs the EPA administrator to work with other relevant agencies to submit recommendations, within 30 days, to the director of the Office of Management and Budget (OMB) on the “legality and continuing applicability” of the agency’s Endangerment and Cause or Contribute Findings for Greenhouse Gases under the Clean Air Act.

Opponents of climate action have long understood the power of the Endangerment Finding and tried unsuccessfully to dismantle it during the first Trump administration. Project 2025 also includes a call to “Establish a system, with an appropriate deadline, to update the 2009 endangerment finding.”

With a new more dangerous Trump administration, thoroughly corrupted by fossil fuel interests—and with the architect of Project 2025, Russell Vought, now confirmed as OMB Director—this time the risk to the Endangerment Finding is definitely greater. Gutting the Endangerment Finding would completely undermine EPA’s ability to regulate greenhouse gas emissions and put a stop to all of EPA’s regulations to limit global warming pollution, a gift to the fossil fuel industry.

But getting rid of the Endangerment Finding is not going to be easy and is by no means a foregone conclusion, as even Lee Zeldin knows. It would require such a brazen effort to lie about climate science evidence that it’s hard to imagine courts going along with that even if the EPA were to take that unwise route.

The Latest Climate Science Is Clear and Alarming

There’s no question that this is a bad faith effort to try to find ways to undercut EPA’s responsibility and authority to regulate heat-trapping emissions under the Clean Air Act. The fact remains that any science-based update to the Endangerment Finding would conclusively demonstrate that the actual harms and projected risks from climate change have only grown grimmer since the 2009 endangerment finding was issued.

As heat-trapping emissions, primarily from burning fossil fuels, continue to rise, global average temperatures too continue their relentless climb with 2024 once again the hottest year on record. Extreme climate-related disasters—including heatwaves, storms, droughts, wildfires, and flooding—are worsening, taking a fearsome toll on people, the economy, and ecosystems. Accelerating sea-level rise, ocean acidification, and loss of major ice sheets also continue apace, with profound consequences for the planet.

If Lee Zeldin is looking for a recent authoritative assessment of the science, he should turn to the 2023 Fifth U.S. National Climate Assessment, produced under the direction of the U.S. Global Change Research Program (USGCRP). The Global Change Research Act of 1990 mandates that the USGCRP—which collaborates across 15 federal agencies—deliver a report to Congress and the president at least every four years.

Here’s the headline from the NCA5:

The effects of human-caused climate change are already far-reaching and worsening across every region of the United States. Rapidly reducing greenhouse gas emissions can limit future warming and associated increases in many risks. Across the country, efforts to adapt to climate change and reduce emissions have expanded since 2018, and U.S. emissions have fallen since peaking in 2007. However, without deeper cuts in global net greenhouse gas emissions and accelerated adaptation efforts, severe climate risks to the United States will continue to grow.

Another valuable source is the IPCC sixth assessment report, which reflects the work of thousands of scientists around the world—including many from the United States—in assessing the latest climate science, impacts, and opportunities to cut heat-trapping emissions and adapt to climate change.

The National Academy of Sciences would also be a good source of information. Here, for example, is a handy booklet on the evidence for and causes of climate change.

NOAA and NASA, premier federal science agencies, also closely monitor and track global climate change and its impacts. (And hopefully will continue to do so—although recent attacks on NOAA, foreshadowed in the Project 2025 manifesto, do not bode well.)

An Anti-Science, Pro-Fossil Fuel Administration

Barely a month into the term of this second Trump administration, it’s clear that the president and his cabinet are hell-bent on doing everything they can to boost fossil fuels and shred climate and clean energy policies, catering to deep-pocketed fossil fuel interests.

They clearly intend to use every means at their disposal (lawful or not) to roll back regulations to help address global warming pollution. Those actions will be rightfully challenged in court, and it takes time to undo regulations in a legal way. However, any delay in implementing strong standards is harmful when the climate crisis is so acute. If the Trump administration succeeds in weakening or stopping EPA’s efforts to cut heat-trapping emissions, that will just leave people bearing the costs while fossil fuel polluters rake in profits.

Revisiting the endangerment and cause or contribute findings is just one more backdoor way to try to advance that harmful agenda. This directive shouldn’t fool anyone. It’s not a genuine effort to engage with scientific facts and listen to climate scientists. After all, the president has called climate change a hoax and many of his cabinet are climate science deniers.

The question for Lee Zeldin is whether he will just pander to that destructive agenda, or will he actually defend the mission of the agency he leads, which is to protect public health and the environment. He has already overseen a series of harmful actions at the EPA—including firing staff, cutting budgets, gutting its environmental justice work, and illegally freezing already-allocated funds for clean energy. So, I doubt we can count on a courageous defense of the endangerment finding from him.

Regardless of how Zeldin responds to President Trump’s directive, this administration cannot hide the reality of climate change. Undoing the Endangerment Finding is such an extremist anti-science endeavor, it is hard to imagine how it could succeed.