An appeals court rejected federal regulators' approval of a $3.5 billion natural gas pipeline project on Tuesday over the issue of climate change.

The United States Court of Appeals for the District of Columbia Circuit ruled that the Federal Energy Regulatory Commission (FERC) failed to fully consider the impact of greenhouse gas emissions from burning the fuel that would flow through the Southeast Market Pipelines Project when the commission approved the project in 2016.

"FERC's environmental impact statement did not contain enough information on the greenhouse gas emissions that will result from burning the gas that the pipelines will carry," the judges wrote in a divided decision. "FERC must either quantify and consider the project's downstream carbon emissions or explain in more detail why it cannot do so."

The 2-1 ruling ordered the commission to redo its environmental review for the project, which includes the approximately 500-mile Sabal Trail pipeline and two shorter, adjoining pipelines. With its first phase complete, the project is already pumping fracked gas from the Marcellus-Utica shale basins of Ohio, Pennsylvania and West Virginia through Alabama, Georgia and Florida.

The appeals court's decision will not immediately affect the flow of gas in the Sabal Trail pipeline, which began operations on June 14, said Andrea Grover, a spokesperson for Enbridge Inc. Enbridge has a 50 percent ownership stake in the Sabal Trail Pipeline through its company Spectra Energy Partners.

FERC declined a request for comment.

The Sierra Club had sued FERC following its approval of the project.

"For too long, FERC has abandoned its responsibility to consider the public health and environmental impacts of its actions, including climate change," Sierra Club staff attorney Elly Benson said in a statement. "Today's decision requires FERC to fulfill its duties to the public, rather than merely serve as a rubber stamp for corporate polluters' attempts to construct dangerous and unnecessary fracked gas pipelines."

The ruling supports arguments from environmentalists that the 1970 National Environmental Policy Act (NEPA), a landmark law that governs environmental assessments of major federal actions, requires federal regulators to consider greenhouse gas emissions and climate change in its environmental assessments.

The ruling is the second federal court decision this month to come to such a conclusion.

On August 14, a U.S. District Court judge rejected a proposed expansion of a coal mine in Montana. The judge ruled that the U.S. Department of Interior's Office of Surface Mining violated NEPA by failing to take into account the project's climate impacts.

In February, outgoing FERC chair and Obama appointee Norman Bay urged the commission to take greenhouse gas emissions from the Marcellus and Utica shale basins into account when reviewing pipeline projects.

"Even if not required by NEPA, in light of the heightened public interest and in the interests of good government, I believe the commission should analyze the environmental effects of increased regional gas production from the Marcellus and Utica," Bay wrote in a memo during his last week in office. "Where it is possible to do so, the commission should also be open to analyzing the downstream impacts of the use of natural gas and to performing a life-cycle greenhouse gas emissions study."

Newly appointed commissioners nominated by President Donald Trump, however, appear unlikely to seek broader environmental reviews for pipeline projects. Before he was confirmed by the Senate to serve as a FERC commissioner earlier this month, Robert Powelson said that people opposing pipeline projects are engaged in a "jihad" to keep natural gas from reaching new markets.