A Seismic Supreme Court Decision

On Friday, the Supreme Court sharply limited the regulatory authority of federal agencies, upending 40 years of legal precedent in a ruling with broad implications for the environment.

The court threw out the so-called Chevron deference, one of the most cited precedents in American law, which has guided courts to defer to the expertise of federal agencies when interpreting unclear laws. Instead, the justices ruled, courts should have more power to interpret these statutes.

As our Times colleagues wrote, environmentalists fear that the decision could lead to hundreds of rules being weakened or eliminated, particularly Environmental Protection Agency limits on air and water pollution, regulations on toxic chemicals, and policies to tackle climate change

The ruling represents a significant win in a decades-long push by conservative organizations to roll back the federal government’s regulatory powers. Mandy Gunasekara, who served as chief of staff at the E.P.A. under President Trump and is a fellow at the Heritage Foundation, celebrated the court’s decision. “It creates a massive opportunity for these regulations to be challenged,” she told The Times. “And it could galvanize additional momentum toward reining in the administrative state writ large if the administration changes in November.”

To find out what could happen next, we reached out to climate experts, legal experts and activists. We asked each expert about the effects of the ruling and how Americans’ lives could be affected.

We’ve excerpted the responses below:

How could everyday life change?

Manish Bapna, president of the Natural Resources Defense Council: “The Court’s actions have put at grave risk the foundational safeguards we depend on, and even take for granted, to protect the mainstays of a modern society. Clean air and water, healthy wildlife and lands; safe food, medicine, workplaces, airplanes, bridges and cars; an economy unhindered by predatory lending, stock fraud and credit card scams.”