This story was originally published by Grist and is reproduced here as part of a collaboration with Climate Desk.
In 2007, the Supreme Court held that the Environmental Protection Agency has the authority to regulate greenhouse gases because it meets the definition of the Clean Air Act for Air Pollutants. This was a crucial moment for US climate control. The ruling led the EPA to find six major greenhouse gases that put carbon dioxide, public health and welfare at risk.
The agency then exploited this so-called dangerous finding to issue rules that would limit tailpipe emissions from vehicles during the Obama and Biden administrations. This is an important tool to reduce nearly 30% of US emissions caused by transportation. For many years, the EPA has relied on dangerous discoveries to regulate climate-warming gases from coal plants, aircraft and other industrial sources.
The discoveries that underpin some of the major EPA rules are currently at risk. According to a Washington Post report, EPA administrator Lee Zeldin recommends the White House break through danger findings. While Trump officials don't appear to have made a decision, the move has long been on the Republican wish list. Project 2025 is an initiative led by the Conservative Heritage Foundation, which outlines policies of the second Trump administration, and proposes establishing a system that “renews 2009 danger discoveries.”
However, experts told Grist that such a dramatic policy change is not easy given that the finding is based on laws passed by Congress and has been supported by courts multiple times.
“It's extremely difficult for the EPA to overturn that finding,” said Romany Webb, deputy director of the Sabin Climate Change Law Center at Columbia University. “There is a huge portion of scientific evidence demonstrating that greenhouse gas emissions contribute to climate change and that climate change is at risk for public health and welfare.
Trump, who attempts to reverse his findings, will almost certainly be challenged in court in his own right. Litigants could refer to the law passed in 2022, when Congress took steps to solidify the findings of the dangers of the law. The Inflation Reduction Act is part of a groundbreaking law that is expected to reduce carbon emissions by about a third by 2030, and includes a provision that amended the Clean Air Act to define carbon dioxide and five other greenhouse gases as air pollutants.
“The fact that Congress has identified greenhouse gases as air pollutants under the Clean Air Act adds to the challenges the EPA faces when revoking dangerous findings,” Webb said.
This finding is also solidified in case law. Over the past 15 years, industry groups and climate skeptics have raised many challenges for danger detection. No one has succeeded. The court has repeatedly reaffirmed the EPA's authority to regulate greenhouse gases. If a new lawsuit is filed, it will likely end before the DC Court of Appeals. The court upheld the authority of government agencies in 2012, noting that the interpretation of the law was “clearly correct.” In December 2023, the Supreme Court recently refused to hear of cases that challenged the discovery.
During Trump's first term, the competitive Enterprise Institute, a conservative think tank and three other groups petitioned the EPA to reconsider its danger findings. However, the Trump EPA refused to do so on the last day of his inauguration, noting that several EPA rules, including some issued by the Trump administration, rely on discoveries.
If the White House is directing the EPA to reverse danger findings, and if Congress moves to repeal the provisions of the Inflation Reduction Act codified the discoveries, the Trump administration will set stages to unravel some key climate regulations. They will do so at a time when it is difficult to ignore the effects of climate change.
“Americans are already devastatingly affected by climate pollution, which has driven worse disasters such as heat waves, floods, more severe fires and hurricanes and dangerous smog levels,” Vicki Patton, general counsel for the nonprofit Environmental Defense Fund, said in a statement. “Efforts like this are reckless, illegal and will ignore the EPA's fundamental responsibility to protect Americans from destructive climate pollution.”
Editor's Note: The Environmental Defense Fund is an advertiser with Grist. Advertisers have no role in Grist's editorial decisions.
