24 states are suing the Trump administration following the administration’s repeal of the “Endangerment Finding” in mid-February. Established in 2009, the Endangerment Finding gave the federal government the authority to regulate air pollutants such as carbon dioxide, methane and nitrous oxide to protect human health and welfare.
Stan Meiburg, former deputy administrator of the Environmental Protection Agency (EPA) and current professor at Wake Forest University, said the repeal is a sweeping rejection of the government’s ability to regulate climate.
“The reason for this approach was that this move was a kind of ‘swing for the fences,’” Meiburg said. “If you could overturn the Endangerment Finding, you could eliminate all authority under the Clean Air Act for regulating carbon emissions.”
The Endangerment Finding historically allowed the EPA to set limits on carbon and vehicle emissions, as well as require carbon capture systems on coal power plants.
However, what the EPA chooses to regulate largely depends on who’s serving as president. Many presidents commenced their time in office by rolling back regulations, just for a successor to come in and expand regulations, until the repeal of the Endangerment Finding.
Without the Endangerment Finding, the federal government cannot regulate greenhouse gases at all.
History of the Endangerment Finding
The Obama administration issued the Endangerment Finding in 2009. This allowed the federal government to issue the Clean Power Plan in an attempt to reduce emissions from power plants by 30%, tighten vehicle emission standards and increase regulations on methane and other toxic emissions from the oil and natural gas industry.
When Donald Trump entered office in 2017, despite rollbacks on these regulations, the U.S.’s carbon emissions were not increasing.
“Wind and solar dramatically outperformed expectations and delivered 13 times more generation than had been projected in 2020,” Meiburg said. “Progress happened anyway… energy consumption between 2000 and 2025 was basically flat because of the increases in efficiency and other technological improvements.”
The Biden administration stepped away from regulations and took a different approach. They passed the Inflation Reduction Act in 2022, focusing on incentives by awarding tax credits for clean energy and electric vehicles. The IRA also invested in electric vehicle charging stations and the greenhouse gas reduction fund.
“It seemed like the Inflation Reduction Act was representing a historic shift from a more regulatory approach of carbon reductions to an incentive approach,” Meiburg said.
When Trump took office again in 2025, his administration argued that regulations were too expensive.
“The Endangerment Finding has been the source of 16 years of consumer choice restrictions and trillions of dollars in hidden costs for Americans,” EPA Administrator Lee Zeldin said in a Feb. 12 press release.
The federal government could still use incentives to lower greenhouse gas emissions, but it’s unclear what will happen now that the Endangerment Finding, the basis for air pollution regulation since 2009, is no longer in effect.
What’s next?
Nearly half of U.S. states are suing the Trump administration, claiming the repeal was illegal.
“The one certainty of this is litigation,” Meiburg said. “It’s certain this will be back in front of the Supreme Court again.”
Meiburg added that the Endangerment Finding’s reveal could push the federal government to pass more climate legislation.
“The Clean Air Act is not going away, but its application to climate is probably the most profound question that stands,” said Meiburg. “If it turns out the Clean Air Act cannot be used in a direct way for regulating carbon emissions, it will throw the ball back into Congress’s lap to decide what it might do.”
The future of climate policy will not be based on science — it will be based on politics. What happens next depends on who is serving in Congress. As the November midterm elections approach, voters may determine the future of environmental regulations.
