EPA wants to reverse a legal finding that greenhouse gas pollution harms public health

America is arguing over how to handle climate change, but the science is clear that greenhouse gases warm the planet and affect health. That scientific picture is colliding with a major shift in federal policy.

In July 2025, the United States Environmental Protection Agency (EPA) proposed to rescind the 2009 endangerment finding, the legal determination that greenhouse gas pollution endangers public health and welfare.

That proposal, if finalized, would remove the basis for federal limits on emissions from new vehicles and some other sources.

What is changing at EPA

Ralph Keeling of Scripps Institution of Oceanography (SIO) has spent decades tracking carbon dioxide in the atmosphere.

His name surfaces here because policy debates about emissions only make sense alongside measured changes in the air.

The endangerment finding is not a minor memo. It is the trigger in the Clean Air Act (CAA) that lets the agency set standards when pollutants harm health or welfare.

Without it, national rules on heat trapping emissions from new cars and trucks would not stand.

“If finalized, rescinding the Endangerment Finding and resulting regulations would end 1 trillion dollars or more in hidden taxes on American businesses and families,” said EPA Administrator Lee Zeldin.

The statement illustrates how the agency is framing the change as economic relief.

Understanding the U.S. Clean Air Act

The Clean Air Act is a law that the U.S. government passed to protect people and the environment from air pollution.

It gives the EPA the power to set limits on how much pollution cars, factories, and power plants can release into the air.

The Act focuses on harmful pollutants such as carbon monoxide, lead, sulfur dioxide, nitrogen oxides, ozone, and tiny particles that can damage our lungs.

By controlling these pollutants, the law helps reduce smog, acid rain, and health problems like asthma or heart disease.

What makes the Clean Air Act especially important is that it doesn’t just set limits once and stop there – it keeps adjusting as science discovers more about how pollution harms us.

For example, over the years, the law has pushed automakers to build cleaner cars and has required industries to use better technology to cut down emissions.

Because of this, the air in the U.S. is much cleaner today than it was fifty years ago, even though the population and number of vehicles have grown.

Why the science matters

In September of 2025, the National Academies Press (NAP) in Washington DC released a consensus report reviewing evidence gathered since 2009.

The committee affirmed that the earlier EPA finding was accurate, has stood the test of time, and is now reinforced by even stronger evidence.

Atmospheric data strengthen that point. NOAA reports a Mauna Loa monthly average of 425.48 ppm for August of 2025, up from 422.99 ppm a year earlier. That steady climb reflects long term human influence on the climate system.

Health research adds context. A 2024 report concluded that climate change is already worsening health risks and straining health systems. Its authors describe “record breaking threats” to wellbeing and survival.

Law links climate to health

The finding connects science to law in a specific way. When a pollutant is deemed to endanger health or welfare, the agency must set standards that are protective.

Pulling back that determination would not just pause one rule. It would remove the legal foundation for a suite of greenhouse gas standards for new vehicles, leaving states and courts to sort out gaps.

Climate project halted

Federal policy is also affecting projects that are already moving forward.

Last month, a nearly complete 65 turbine offshore wind project valued at about $6 billion was ordered to stop work, with developers reporting about 80 percent completion and power planned for roughly 350,000 homes in Rhode Island and Connecticut.

Halting a large buildout mid stream disrupts jobs, local supply chains, and grid planning. Communities that counted on a new source of electricity must now plan around a delay that may last through litigation.

Missing climate data harms health

Climate decisions depend on shared facts. In July of 2025, the federal climate research program that hosts the legally mandated National Climate Assessment was reported inactive by the Congressional Research Service.

Losing easy access to assessments and datasets slows down work that cities and states do to prepare for floods, heat, and wildfire smoke.

Emergency managers, planners, and school districts rely on those tools to decide where to invest and how to protect vulnerable residents.

Checks and balances still apply

A proposal is not a final rule. The endangerment rollback must go through notice and comment, respond to evidence, and survive court review.

States, public health groups, and industry will weigh in with data and legal arguments. That process matters because decisions at this scale shape the cars we buy, the air we breathe, and the bills we pay.

Climate, health and politics

Two things can be true at once. The nation can debate how to reach energy goals while the scientific case for the harms of greenhouse gases continues to tighten.

Policy choices should account for costs and benefits that show up in real lives.

Heat waves, smoke days, and flood risks do not care about political cycles, and health impacts land hardest on people with the fewest options.

What to watch next

Watch the docket for the final EPA decision and the evidence it cites. Also watch whether Congress moves to protect, or constrain, the agency’s authority.

Keep an eye on the NAP follow-through and on whether federal data portals return to full service. Communities will need timely, transparent information to plan for heat, water, and energy reliability.

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