In August, the D.C. Circuit Court of Appeals ruled FERC did not properly evaluate the effects of greenhouse gas emissions from the natural gas shipped by the pipeline, in issuing a prior approval of the project.

The ruling applied to the Southeast Market Pipelines Project, a network that includes the Sabal Trail pipeline to move natural gas across a number of states for delivery at Florida power plants.

That means FERC’s environmental impact statement for the project should quantify the emissions from the power plants that ultimately burn natural gas delivered by the pipelines, a process the court said is required under the National Environmental Policy Act.

But on Wednesday, FERC reinstated its approval of the project, saying it could not determine the significance of the greenhouse gas emissions of burning the gas transported by the pipeline, an analysis that does not change the commission’s conclusion that the project is environmentally safe.

FERC’s two Democratic commissioners dissented from the majority’s contention that it could not evaluate the significance of carbon emissions.

“Willful ignorance of readily available analytical tools to support an enhanced qualitative assessment for the single largest environmental threat in our lifetime will undermine informed public comments and informed decision-making,” said commissioner Richard Glick, a Democrat nominated by President Trump. “The commission should not fear adding transparency to its decision-making process. Rather, we should embrace the opportunity to disclose the effects which may not always be adverse.”

Cheryl LaFleur, a fellow Democrat, said she supports the proposed pipeline network “after carefully balancing the need for the project and its environmental impacts.”

But she said she is “troubled by the manner in which today’s order addresses the significance” of greenhouse gas emissions.

“The order fails to even concede that GHG emissions are an indirect impact that must be quantified in NEPA,” LaFleur, a nominee of former President Barack Obama, wrote in dissent. “More broadly, the order asserts that GHG emissions quantifications cannot ‘meaningfully inform’ our public interest determination. I fundamentally disagree. I reject the contention that the commission is unable to discern the significance of GHG emissions.”

FERC, an independent government agency that approves and regulates the interstate transmission of electricity, natural gas, and crude oil, approved the nearly 700-mile long Southwest Market pipelines in 2016, but it hasn’t been built.

In the past, FERC had minimal obligations in considering greenhouse gas emissions and the effect on climate change when reviewing pipeline permits.

FERC has examined the environmental effects of physically building the pipeline, not the effects of using the fuel it transports.

LaFleur said she was hopeful FERC will soon adopt a broader approval policy for pipelines that better incorporates climate change considerations.

FERC is currently reviewing its nearly 20-year-old policy for approving pipeline projects as the agency evaluates how to best manage the transport of bountiful shale natural gas to market, while balancing environmental and climate change concerns.

As it stands, FERC makes decisions about pipelines based mostly on the economic need for the project, seeing whether developers have secured contracts with companies that want to use the pipeline to ship fuel.

“I believe that the best way to address climate change… in pipeline dockets would be for the commission to develop a more complete record on costs and benefits of the proposed project, including more information on the need for a project, the likely end-uses of the transported gas, and the alternatives,” LaFleur said.