The guidance from President Trump's administration would limit the extent to which federal agencies can calculate their greenhouse gas emissions. (Andrew Harrer/Bloomberg)

The White House proposed Friday that federal agencies no longer have to take a project’s long-term climate impacts into account when assessing how they will affect the environment, reversing a major Obama administration policy.

The draft guidance, issued by the White House Council on Environmental Quality, would change the way the U.S. government evaluates activities ranging from coal mining to gas pipelines and oil drilling by limiting the extent to which agencies can calculate their greenhouse gas emissions. In April 2016, CEQ finalized a directive that agencies quantify to what extent they will contribute to climate change, a move that threw approval of those projects into doubt.

Now, according to the new directive, agencies conducting reviews under the National Environmental Policy Act (NEPA) only have to calculate an action’s greenhouse gas emissions when “a sufficiently close causal relationship exists” between a project and greater carbon emissions. It also tells agencies they can opt not to assess a project’s climate impact if they decide it “would be overly speculative,” and they can put any projected emissions in the context of the local, regional or national carbon output.

The move, which comes two days after the Environmental Protection Agency scaled back greenhouse gas requirements for power plants, is the Trump administration’s latest effort to sideline climate considerations in federal decision-making. But legal experts warned it could cause further problems for the administration in court, where judges have suggested officials need to do a better job of assessing the climate impact of their decisions.

Mary Neumayr, who chairs the CEQ, said in a statement that the proposal would speed the construction of major infrastructure projects in the United States.

“The administration is working to make the environmental review process for major infrastructure projects more efficient, timely and effective,” Neumayr said. “CEQ’s draft guidance is intended to assist agencies in meeting their obligations under NEPA and to improve the timeliness of permitting decisions for projects to modernize our nation’s infrastructure.”

The question of to what extent federal decisions are fueling climate change has emerged as a major legal and political issue under the Trump administration. Federal judges have halted oil and gas leasing on multiple occasions on the grounds that the federal government failed to properly calculate a project’s carbon output, including in March when a judge blocked leasing on 300,000 acres in Wyoming.

According to an analysis by the Center for American Progress, a liberal think tank, the Trump administration has lost a dozen court cases over agencies’ failure to adequately consider climate issues as part of NEPA reviews. In April, for example, a court held that the Interior Department violated NEPA by not considering climate issues when it lifted a federal moratorium on new coal leasing.

“This proposed replacement for the 2016 guidance is softer and may allow for less quantification, but it doesn’t change the underlying statutory requirement” to analyze how government projects are affecting the climate, said Michael B. Gerrard, director of the Sabin Center for Climate Change Law at Columbia Law School.

Because prior court cases have required agencies to take climate change into account, the new guidance is trying to finesse that and require them not to do very much, said Mark Templeton, who directs the Abrams Environmental Law Clinic at the University of Chicago.

“The guidance provides a blueprint for agencies seeking to minimize the costs of greenhouse gas emissions by counseling them to present emissions as an inevitably minuscule percentage of total global emissions,” Templeton said in an email.

Congressional Republicans hailed the new guidance: Senate Environment and Public Works Committee Chairman John Barrasso (R-Wyo.) said it “will help ensure that major energy projects in Wyoming and across the country can move forward without needless delays and litigation."

But Christy Goldfuss, who helped write the Obama administration’s climate guidance and is now at the Center for American Progress, said in an email that global warming will affect Americans even if the current administration fails to account for it. “With record-breaking storms and the recent devastating floods in the Midwest, climate impacts are looming large — the federal government ignores them at their own peril.”

Chris Mooney contributed to this report.