EPA Endangerment Finding Rescinded: Science, Law, and Climate Regulation

In this Science Friday episode, Flora Lichtman talks with Dr. Andy Miller, an original author of the endangerment finding, about the Obama-era ruling that greenhouse gases are air pollutants and the legal pathway it created for EPA regulation under the Clean Air Act. They explore how the Massachusetts versus EPA decision triggered the process, what it enabled on vehicles and power plants, and Miller’s view that the science behind climate change remains robust even as the finding is rescinded. The conversation also examines potential regulatory fragmentation and ongoing global pressures that will continue to push for cleaner vehicles and power generation, regardless of this legal change.

Background: Endangerment Finding and its Legal Basis

The episode opens with Flora Lichtman outlining the rescission of the 2009 endangerment finding, a cornerstone EPA rule that defined greenhouse gases as air pollutants under the Clean Air Act. Dr. Andy Miller, an original author on the finding with more than 30 years at EPA, explains that the finding provided the legal framework for EPA regulation, especially for vehicle emissions standards. The Massachusetts versus EPA decision, decided by the Supreme Court in 2007, is described as the trigger that forced EPA to treat greenhouse gases as pollutants and begin the regulatory process. Miller notes that without the endangerment finding, EPA would have faced major regulatory hurdles.

“The science wins” - Dr. Andy Miller

Miller emphasizes that the internal scientific work proceeded through standard review channels, culminating in a rule during the Obama administration that allowed vehicle emissions standards to be set without new congressional action. The segment also highlights how the shift from coal to natural gas and more renewables was already driving emissions down, complicating efforts to quantify the regulatory impact beyond vehicles.