An appeals court on Tuesday rejected the federal government’s approval of a natural gas pipeline project in the southeastern U.S., citing concerns about its impact on climate change.

In a 2-1 ruling, the Court of Appeals for the District of Columbia Circuit found that the Federal Energy Regulatory Commission (FERC) did not properly analyze the climate impact from burning the natural gas that the project would deliver to power plants.

The ruling is significant because it adds to environmentalists’ arguments that analyses under the National Environmental Policy Act — the law governing all environmental reviews of federal decisions — must consider climate change and greenhouse gas emissions.

The case concerns the Southeast Market Pipelines Project, which is meant to bring gas to Florida to fuel existing and planned power plants.The Sierra Club sued FERC following its 2016 approval of the project. The environmental group brought a series of objections to the project and its environmental review, but the court denied all of the objections except the one focused on greenhouse gas.

The environmental impact statement for the project “should have either given a quantitative estimate of the downstream greenhouse emissions that will result from burning the natural gas that the pipelines will transport or explained more specifically why it could not have done so,” Judge Thomas Griffith, who was nominated to the court by President George W. Bush, wrote in the opinion. He was joined by Judge Judith Ann Wilson Rogers, one of President Bill Clinton‘s nominees.

“As we have noted, greenhouse-gas emissions are an indirect effect of authorizing this project, which FERC could reasonably foresee, and which the agency has legal authority to mitigate,” Griffith said.

“Quantification would permit the agency to compare the emissions from this project to emissions from other projects, to total emissions from the state or the region, or to regional or national emissions-control goals. Without such comparisons, it is difficult to see how FERC could engage in ‘informed decision making’ with respect to the greenhouse-gas effects of this project, or how ‘informed public comment’ could be possible,” the court wrote, quoting previous cases regarding environmental reviews.

Judge Janice Rogers Brown, another Bush nominee, dissented from the ruling, arguing that FERC does not have the authority to take action to reduce the greenhouse gas impact of pipelines it approves, so it is not obligated to analyze some impacts.

The court’s decision overturns the project’s federal approval and returns the issue to FERC to complete the necessary greenhouse gas analysis.