The Trump Administration Has Clean Air Protections in Its Crosshairs

Many U.S. clean air policies rest on one key assertion by the Environmental Protection Agency (EPA). In 2009, it found that greenhouse gases are air pollutants that endanger public health and welfare by driving climate change. As such, gases like carbon dioxide and methane are subject to regulation under the Clean Air Act.

Now, despite increasing and intensifying droughts, wildfires, and other climate-change fueled disasters, Trump’s EPA is changing course. It is seeking to withdraw the endangerment finding entirely or weaken its role in regulating pollution sources such as cars and trucks, power plants, and fossil fuel drilling.

The stakes could not be higher for the health and well-being of communities across the U.S. Earthjustice will see the administration in court if it attempts to revoke this commonsense determination.

Read on to learn more about where the finding came from and why it matters.

A Supreme Court order and a pile of scientific evidence

The EPA’s determination was the result of a historic Supreme Court case. In 2007, the court ruled in Massachusetts v. EPA that the agency had the authority to regulate greenhouse gases under the Clean Air Act.

This meant that the EPA was required to determine whether greenhouse gases pose a risk to public health, and make rules to protect the public if so. Faced with a trove of scientific research that links greenhouse gases to a warming, chaotic climate, the agency released the endangerment finding in 2009. Since then, it has served as a basis for rules limiting greenhouse gas emissions.

Firefighters battle the Palisades Fire as it burns multiple structures in the Pacific Palisades neighborhood of Los Angeles, Tuesday, Jan. 7, 2025. (Ethan Swope / AP)

The case for the finding has only gotten stronger

As of 2024, the last 10 years have all been the hottest on record amid increasing extreme weather events. The cost of natural disasters driven by climate change is skyrocketing. As just one example, the wildfires that ravaged L.A. this winter are estimated to have caused more than $250 billion in damage.

Meanwhile, the endangerment finding has withstood several industry-backed legal challenges, including one that Earthjustice helped defeat in court. In 2023, the U.S. Circuit Court in D.C. unanimously rejected the most recent challenge by an oil industry group and a collection of climate deniers, and the Supreme Court declined their request to appeal.

Looming threats from the Trump administration

In March, EPA Administrator Lee Zeldin announced that the agency would begin to “formally reconsider the Endangerment Finding” in response to President Trump’s day-one executive order, “Unleashing American Energy.” Project 2025, the polluter-friendly agenda that has guided many of the Trump administration’s policy decisions, called for exactly this move.

What are some of the major regulations that depend on the finding?

Emissions from the Linden Cogeneration Plant is seen in Linden, New Jersey. (Kena Betancur / Getty Images)

Limits on power plant emissions

Power plants are responsible for roughly a quarter of climate pollution in the country — particularly carbon dioxide, which makes up 80% of greenhouse gas emissions. Yet until last year, these plants had a free pass to dump climate-warming emissions into the air.

In 2024, the EPA proposed standards that require new gas and existing coal-fired power plants to reduce their carbon pollution by 90%. The agency projected that the new standards would cut annual carbon emissions by the same amount as taking 328 million gas-powered cars off the road. The rule also has significant public health benefits, potentially averting up to 1,200 premature deaths a year by 2035.

A technician uses a hammer while working on the underside of an Altima sedan at Nissan’s Canton Vehicle Assembly Plant in Canton, Mississippi. Nissan plans to build two all-new electric models at the plant starting in 2025. (Rogelio V. Solis / AP)

Limits on vehicle emissions

Another giant source of carbon dioxide is transportation. Emissions from gas-powered vehicles make up the largest source of CO₂ in the country. In March 2024, the EPA finalized new car pollution standards that move us towards a pollution-free future. The agency lowered the maximum amount of tailpipe emissions allowed from new cars, starting in model year 2027.

This isn’t a ban on gas cars; instead, it pushes automakers to increase the amount of zero-emissions vehicles per fleet each year to balance out emissions from gas-powered cars and light trucks. The new standards represent an almost 50% reduction in CO₂ emissions compared to existing standards for model year 2026 vehicles.

A gas flare is seen at an oil well site outside Williston, North Dakota. (Andrew Burton / Getty Images)

Limits on methane emissions from oil and gas drilling

As the country transitions to a clean energy economy, the fossil fuel industry has tried to frame “natural” methane gas as a climate-friendly energy source. It’s not: Methane traps over 80 times more heat in the atmosphere than CO₂. It is responsible for approximately one-third of the global warming we are experiencing today. (Both CO₂ and methane are major contributors to the climate crisis, and CO₂ remains the most abundant greenhouse gas.)

Each year, fossil fuel companies leak or deliberately vent 13 million metric tons of methane into the atmosphere during oil and gas operations. In 2023, after years of legal advocacy by Earthjustice, the Biden administration issued a final rule that cuts 80% of methane from those oil and gas facilities, which are the main source of methane emissions.

The rule requires industries to adopt precise methane detection technology, update facility equipment to run on zero emissions, and reduce “fugitive emissions” — unintended methane emission leaks from oil and natural gas equipment, like pipelines and storage tanks.

For decades, Earthjustice’s litigation has helped strengthen the laws that protect communities from dirty air and reduce climate pollution. We will not cede this progress.