In a 6–2 decision, the Supreme Court upheld the Environmental Protection Agency’s (EPA) Cross-State Air Pollution Rule, also known as the Transport Rule.

The Clean Air Act includes a “good neighbor” provision to deal with air pollution emitted in one state that causes harm in another. The EPA interpreted this provision and adopted the Transport Rule, which affects 28 states, to attempt to reduce nitrogen oxide and sulfur dioxide emissions that cross state lines; the air quality of some states is affected by the emissions from other states.

In 2012, the U.S. Court of Appeals for the D.C. Circuit held that the rule exceeded the EPA’s authority because “upwind States may be required to reduce emissions by more than their own significant contributions to a downwind State’s nonattainment.” In other words, some states would be responsible for more than their fair share of reducing emissions.

The D.C. Circuit also held that the rule failed to give states an opportunity to implement their own plans to reduce emissions.

Today, in an opinion by Justice Ruth Bader Ginsburg, the Court upheld the rule, giving deference to the agency’s decision in how to allocate responsibility among upwind states because it was a “permissible construction” of the Clean Air Act and holding that states don’t have to be provided a chance to develop their own plans to reduce emissions.

Justice Antonin Scalia, joined by Justice Clarence Thomas, in dissent, captured the problems with the rule:

Too many important decisions of the Federal Government are made nowadays by unelected agency officials exercising broad lawmaking authority, rather than by the people’s representatives in Congress. With the statute involved in the present cases, however, Congress did it right. It specified quite precisely the responsibility of an upwind State under the Good Neighbor Provision: to eliminate those amounts of pollutants that it contributes to downwind problem areas. But the Environmental Protection Agency was unsatisfied with this system. Agency personnel, perhaps correctly, thought it more efficient to require reductions not in proportion to the amounts of pollutants for which each upwind State is responsible, but on the basis of how cost-effectively each can decrease emissions.

[T]he majority relieves EPA of any obligation to announce novel interpretations of the Good Neighbor Provision before the States must submit plans that are required to comply with those interpretations. By according the States primacy in deciding how to attain the governing air-quality standards, the Clean Air Act is pregnant with an obligation for the Agency to set those standards before the States can be expected to achieve them. The majority nonetheless approves EPA’s promulgation of federal plans implementing good-neighbor benchmarks before the States could conceivably have met those benchmarks on their own. [Emphasis in original.]

This decision goes against the cooperative federalism Congress embodied in the Clean Air Act. States should be concerned that they weren’t given a chance to develop state implementation plans. They should be particularly concerned about whether this is a sign of more to come. The Transport Rule is further proof of a growing trend by EPA bureaucrats to force one-size-fits-all policies on the states and their citizens.