Democrats, anticipating Chevron’s demise, gave E.P.A. more power in recent climate law.

The Biden administration has been preparing for the overturn of Chevron, knowing that conservative activists have pushed cases like this, and that the majority of justices on the Supreme Court were expected to look favorably on it.

That’s why two years ago the White House worked with congressional Democrats to squeeze through legislation that could help protect the Environmental Protection Agency’s authority to craft climate change regulations, even if the Chevron doctrine was struck down.

Climate change rules could be particularly vulnerable to legal attack in a post- Chevron world. That’s because the E.P.A. wrote them under the authority of the 1970 Clean Air Act, a sweeping law that directs the agency to regulate all pollutants that endanger human health.

But the legislators of 1970 did not specify anywhere in the law that carbon dioxide emissions, the chief cause of climate change, should be regulated. It doesn’t even mention climate change.

Democrats changed that in the 2022 Inflation Reduction Act, a law chiefly focused on spending billions of dollars on clean energy technology to fight climate change. But the law amends the Clean Air Act to define the carbon dioxide produced by the burning of fossil fuels as an “air pollutant.”

That language, according to legal experts as well as the Democrats who worked it into the legislation, explicitly gives the E.P.A. the authority to regulate greenhouse gases and to use its power to push the adoption of wind, solar and other renewable energy sources.

The specificity of that legal language should protect E.P.A.’s authority to regulate carbon dioxide pollution by limiting their emission from tailpipes and smokestacks.

However, opponents of the rule — chiefly, the fossil fuel industry