A U.S. appeals court on April 30 upheld federal approvals for a natural gas pipeline system expansion project in Louisiana and Mississippi, rejecting environmentalists’ claims that the government performed an insufficient review of its climate harms.

A unanimous three-judge panel of the U.S. Circuit Court of Appeals for the D.C. Circuit held that the Federal Energy Regulatory Commission (FERC) was right to determine the Evangeline Pass Expansion project is functionally separate from four related gas infrastructure developments being developed independently. FERC therefore did not need to analyze their emissions together, the D.C. Circuit said.

The Kinder Morgan-backed project would expand existing pipelines to feed more fuel to Venture Global's Plaquemines LNG export terminal in the Gulf of Mexico.

The Sierra Club and Healthy Gulf said in their 2022 lawsuit seeking to vacate FERC's approvals that the expansion and the related projects — new pipeline infrastructure projects that connect to the same export terminal and to the terminal itself — would together cause a massive release of greenhouse gas emissions.

But the D.C. Circuit said on April 30 that since the other projects have separate ownership and would likely be built anyway, FERC was not obligated under federal environmental review laws to consider their collective emissions when issuing approvals.

The environmental groups, Kinder Morgan and FERC didn’t immediately respond to requests for comment.

The projects are all part of a major buildup of LNG export capacity in the Gulf. The U.S. last year became the world’s largest LNG exporter, and that capacity is expected to double before the decade ends.

The environmental groups had argued that FERC violated the National Environmental Policy Act when it segmented its analysis of Evangeline Pass' environmental harms from the other projects.

The groups said the projects are connected because the terminal won’t be able to export gas without supply from the pipelines, and the pipelines wouldn’t have anywhere to put the gas without the terminal.

FERC had argued in court that the cumulative analysis demanded by the environmental groups wasn’t necessary because the individual projects would likely proceed regardless of whether the Evangeline Pass project is approved.

The Evangeline Pass expansion is currently under construction. Work on the Plaquemines terminal is also ongoing and its first exports are expected later this year.

The case is Alabama Municipal Distributors Group v. Federal Energy Regulatory Commission, U.S. Circuit Court of Appeals for the D.C. Circuit, lead case No. 22-1101.