The ruling in this case was unanimous but the conservatives and the liberals wrote separate decisions reaching the same conclusion. The conservative decision was written by Justice Kavanaugh and the liberal one by Justice Sotomayor. Justice Gorsuch recused himself from this one because Democrats and environmental groups had complained a billionaire ally of his, Philip Anschutz, had a financial stake in the case. If they were hoping his recusal would help their chances, it didn't work out that way. It's an 8-0 decision instead of 9-0.

Ultimately, the decision limits the scope of environmental reviews mandated by a Nixon-era law called the National Environmental Policy Act (NEPA) in a way that should make it easier for developers to build big projects. It's being seen as a big setback for environmentalists. 

The case is about a railway which was proposed in northern Utah. If built, the railway would allow production of oil in the north of Utah by connecting it to refineries along the Gulf Coast. Before it could be approved, the developers had to perform a time-consuming environmental review known as an environmental impact statement (EIS). They did so, producing a report that was 3,600 pages long.

The environmental impact statements required by a 1970 federal law, the National Environmental Policy Act, can be quite elaborate. Paul D. Clement, a lawyer representing seven Utah counties that support the project, told the justices when the case was argued in December that the law was “the single most litigated environmental statute.”

He added that the board had acted responsibly.

“It consulted with dozens of agencies, considered every proximate effect and ordered 91 mitigation measures,” he said, referring to measures intended to, among other things, dampen noise pollution and protect wildlife. “Eighty-eight miles of track should not require more than 3,600 pages of environmental analysis.”

But environmental groups said that wasn't enough. They sued and argued that the review of the 88-mile railway did not look at possible upstream and downstream consequences of its construction. For instance, if completed, the railway would lead to more jobs in northern Utah drilling oil which could impact the environment there. And the delivery of more of that oil to the Gulf Coast (using the new rail line) could impact the Gulf Coast environment as well.

A DC Court of Appeals heard the case and sided with the environmental groups, saying the 3,600 page EIS didn't go far enough. They vacated the approval of the project until the other possible consequences could be considered.

But today the Supreme Court unanimously said enough is enough. Environmental reviews are limited to consideration of the project at hand, not every conceivable consequence. From the decision written by Justice Kavanaugh:

Simply stated, NEPA is a procedural cross-check, not a substantive roadblock. The goal of the law is to inform agency decision making, not to paralyze it...

The Board's EIS addressed the environmental effects of the railroad line. But the U. S. Court of Appeals for the D. C. Circuit nonetheless faulted the EIS for not sufficiently considering the environmental effects of projects separate from the railroad line itself—primarily, the environmental effects that could ensue from (i) increased oil drilling upstream in the Uinta Basin and (ii) increased oil refining downstream along the Gulf Coast of Louisiana and Texas.

On that basis, the D. C. Circuit vacated the Board's EIS and the Board's approval of the 88-mile railroad line. As a result, construction still has not begun even though the Board approved the project back in December 2021.

We reverse. First, the D. C. Circuit did not afford the Board the substantial judicial deference required in NEPA cases. Second, the D. C. Circuit ordered the Board to address the environmental effects of projects separate in time or place from the construction and operation of the railroad line. But NEPA requires agencies to focus on the environmental effects of the project at issue. Under NEPA, the Board's EIS did not need to address the environmental effects of upstream oil drilling or downstream oil refining. Rather, it needed to address only the effects of the 88-milerailroad line. And the Board's EIS did so.

As mentioned above, the court's liberals reached the same conclusion but came at it in a somewhat narrower way.

The court’s three liberals – Justices Sonia Sotomayor, Elena Kagan and Ketanji Brown Jackson – agreed with the outcome of the case but had different reasoning. Writing for the three, Sotomayor said that such environmental reviews conducted by federal agencies should be limited to their own expertise. The Surface Transportation Board, which conducted the review in this case, is primarily focused on transportation projects, not oil refining.

“Under NEPA, agencies must consider the environmental impacts for which their decisions would be responsible,” Sotomayor wrote. “Here, the board correctly determined it would not be responsible for the consequences of oil production upstream or downstream from the railway because it could not lawfully consider those consequences as part of the approval process.”

This decision should limit environmentalists' ability to endlessly multiply the federal requirements put upon developers trying to complete a project. From now on they only need consider the project at hand.