What repealing the ‘endangerment finding’ means for public health
The EPA has scrapped a rule stating that climate change harms human health. Here’s what that could mean
The Trump administration’s decision to scrap the “endangerment finding” on Thursday will have wide-reaching consequences for greenhouse gas emissions and, ultimately, could hasten climate change, increase risk to human health and raise fuel costs.
But what is the “endangerment finding,” and what does the revocation of this 2009 conclusion mean for you? Let’s break down the facts.
What is the endangerment finding?
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To understand the endangerment finding, we need to rewind the clock to the Clean Air Act, the landmark 1970 law that allows the Environmental Protection Agency to regulate air pollutants.
The act was originally used to target pollutants such as sulfur oxides and particulate matter, but it was intentionally written broadly so that Congress wouldn’t have to revisit the it every time a new pollutant emerged, said Camille Pannu, associate clinical professor of law at Columba Law School, to Scientific American last year.
In 1999 a group of environmental organizations and eventually states began petitioning the EPA to regulate greenhouse gases under the Clean Air Act. Eventually, in 2007, the Supreme Court decided in the case Massachusetts v. EPA that greenhouse gases, including carbon dioxide, qualified as “air pollutants” under the Clean Air Act. The EPA was required to determine whether or not emissions from cars and trucks would endanger public health or if the science was too uncertain.
Flash forward to 2009: Lisa P. Jackson, then administrator of the EPA, issued the “endangerment finding,” which identified six greenhouse gases and held that they did indeed “threaten the public health and welfare of current and future generations.” The rule became the bedrock on which all subsequent EPA regulations of greenhouse gases have been based. While it was in place, the EPA could not legally ignore climate change or completely cut greenhouse gas regulations.
What effect does repealing the endangerment finding have?
In the short term, EPA regulations on greenhouse gas emissions and fuel efficiency standards for new cars and trucks will be repealed and not replaced. The decision to repeal the rule, however, will face lengthy legal challenges.
The EPA has also proposed repealing regulations on industrial emissions and delaying rules designed to reduce methane emissions, one of the most potent greenhouse gases, from oil and gas facilities.
Rescinding the endangerment finding will also make it harder for future administrations to regulate carbon dioxide and other greenhouse gases under the Clean Air Act without a new law or amendment passed by Congress.
How does climate change affect public health?
There is a robust body of evidence showing the harms of climate change on health. One of the most direct risks is through heat waves, which have become more intense, more frequent and longer-lasting as global background temperatures have risen. Children, pregnant people, older people and those who work outdoors are particularly susceptible to heat illness—causing issues from dehydration to death.
Climate change has also been linked to worsened seasonal allergies and higher risks of preterm birth. Additionally, it exacerbates smog and other air pollution that has been linked to asthma, cardiovascular disease and adverse pregnancy outcomes. More extreme rains fueled by a warmer climate also raise the risks of drinking water being contaminated with toxic bacteria such as Salmonella and Campylobacter. And as temperatures warm and precipitation patterns change, insects that spread diseases—such as mosquitoes that spread malaria and West Nile virus and ticks that spread Lyme disease—are expanding their ranges.
Climate change also exerts a toll on mental health, causing mental trauma—as well as physical injury—from climate-fueled weather extremes such as hurricanes, floods and wildfires. And research has shown that the effects from events such as hurricanes can cause deaths long after the storms.
Has the endangerment finding been at risk before?
In President Donald Trump’s first term in office, then EPA administrator Scott Pruitt sought to replace Obama-era emissions regulations with weaker ones that were favored by fossil fuel companies, the industrial sector and car companies. This strategy would have allowed the endangerment finding to stand, dodging potential legal challenges.
When President Joe Biden took office in 2021, his EPA replaced those weakened regulations with more stringent ones. At the end of his presidency in 2024, Biden announced his pledge to reduce U.S. emissions by up to 66 percent by 2035. Overturning Biden’s updated laws has become a focal point of Trump’s second term.
How does this fit in with the rest of Trump’s climate policy?
Trump has long referred to climate change as a “hoax” despite decades of rigorous research and evidence in support of global warming. He began his second presidency by once again removing the U.S. from the Paris climate agreement to limit warming to below 1.5 degrees Celsius. In 2026 Trump also withdrew the U.S. from the United Nations Framework Convention on Climate Change, the treaty under which the Paris Agreement was negotiated.
The current Trump administration has also sought to hobble the build-out of renewable energy in the U.S., particularly offshore wind turbines, which the president has falsely linked to the deaths of whales. And the administration has sought to bolster fossil fuels by opening more federal lands to drilling and ordering coal plants that were marked for retirement to stay open.
Editor’s Note (2/12/26): This article was edited after posting to correct the descriptions of Massachusetts v. EPA and the endangerment finding.
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