The Trump administration will instruct federal agencies to no longer take climate change into account when measuring the impact of major infrastructure projects, according to two senior administration officials — a sweeping overhaul of one of the nation’s most consequential environmental laws.

The proposed changes to the 50-year-old National Environmental Policy Act are aimed at speeding approvals for pipelines, oil and gas leases, highway construction and other kinds of development. The law, which was last updated in 1978, has proved one of the most potent stumbling blocks to President Trump’s push to accelerate oil, gas and coal extraction across the country.

Under NEPA, agencies are required to analyze the extent to which proposed federal actions affect everything from endangered species to water quality to greenhouse gas emissions linked to climate change.

Under the Obama administration, the Environmental Protection Agency raised objections during a NEPA review of the giant Keystone XL pipeline that delayed it. More recently, federal judges halted oil and gas leasing in Wyoming as well as the Trump administration’s push to restart coal leasing on public land on the grounds that the Interior Department did not properly assess the climate impacts of these decisions.

Two administration officials, who spoke on the condition of anonymity because the proposed changes will not be announced until next week, said the plan will shorten the time frame for the environmental reviews. The reviews also will no longer consider the cumulative effects of a project, they said.

“Climate change is no longer a top priority for these reviews,” one official said.

The New York Times first reported details of the proposal Friday evening.

In a statement on Jan. 1, the law’s 50th anniversary, Trump criticized the extent to which it has delayed projects.

“While the goals of NEPA remain the same as they did 50 years ago, the environmental review process designed to improve decision making has become increasingly complex and difficult to navigate,” the president said in the statement. “Project sponsors and ordinary Americans seeking decisions on permits from the federal government can face significant uncertainty and delays that can increase costs, derail important projects, and threaten jobs for American workers and labor union members.”

Stephen Schima, senior legislative counsel for the nonprofit organization Earthjustice, said in an interview that the effect of the proposal could be enormous. NEPA “sets the floor” for how more than 80 federal agencies solicit public input and evaluate the government’s impact on the environment, he said.

“They’re clearly trying to institutionalize climate denial into federal decision-making,” Schima said. “This is the existential threat to how the government incorporates climate change into their decision-making process.”

The regulations would have to be finalized before they could take effect, and environmental groups are sure to challenge them in court.

Industry and some union officials have urged the White House to overhaul the decades-old policy and make it easier to launch transit and highway projects, drilling and other developments. Trump is particularly interested in the plan because he thinks it will accelerate the construction of pipelines across the country.

“POTUS is obsessed with pipelines,” one official said. “He wants to get these pipelines built.”

Barely a month ago, a collection of major industry groups — including the American Petroleum Institute, the National Association of Home Builders and the American Chemistry Council — wrote to administration officials that overhauling NEPA would boost the economy.

“Reducing delays and uncertainties associated with infrastructure investment and related projects has the potential to support more and better-paying jobs throughout the country,” the coalition wrote to the head of the White House’s Council on Environmental Quality. “Improved regulatory predictability would allow businesses to plan and invest with confidence while enhancing economic productivity and efficiency.”

Daniel Schneider, a spokesman for the White House council, declined to comment in detail about the proposal. But in an email, he noted, “CEQ’s NEPA regulations have not been comprehensively updated in more than 40 years.”

“President Trump promised a more efficient process to provide Americans timely decisions on permits for vital infrastructure projects that provide good jobs, reduce traffic congestion, and enhance the quality of life in neighborhoods across our great country,” Schneider said. “The Trump administration is focused on improving the environmental review and permitting process while ensuring a safe, healthy, and productive environment for all Americans.”