What matters to me today is the Endangerment Finding Is Dead. Massachusetts v. EPA May Be Next.
The U.S. Environmental Protection Agency has finalized and will publish tomorrow (2/18/2026) its rescission of the 2009 Endangerment Finding—the legal foundation for federal regulation of greenhouse gases from motor vehicles. That single administrative action launched the modern era of federal climate regulation. Its repeal may mark the beginning of the end.
Importantly, EPA did not base its decision on new climate science. Instead, it concluded that the Clean Air Act was never meant to address global climate change in the first place. In EPA’s view, Congress empowered the agency to regulate pollutants causing local or regional harm—not global atmospheric conditions driven by worldwide emissions. The agency also invoked the Supreme Court’s “major questions doctrine,” arguing that sweeping climate policy decisions belong to Congress, not regulators.
Which brings us to the elephant in the room: Massachusetts v. EPA. In 2007, the Supreme Court held that greenhouse gases fit within the Clean Air Act’s definition of “air pollutants,” forcing EPA to confront the Endangerment Finding. EPA now argues that decision was misunderstood—and did not require regulating climate change.
That argument will be tested. Litigation is inevitable, and the Supreme Court may soon revisit its landmark climate precedent.
Whatever your views on climate policy, one thing is certain: the Endangerment Finding was the legal keystone of federal greenhouse gas regulation. With its rescission, the entire regulatory arch is now in question.
That’s what matters to me today in 250 words or less. What matters to you? I’d really like to know.