The National Environmental Policy Act, or N.E.P.A., was signed into law by President Richard M. Nixon in 1970, after several environmental disasters including a crude oil spill off the coast of Santa Barbara, Calif., and a series of fires on the heavily polluted Cuyahoga River in Ohio that shocked the nation.
It mandates federal agencies to assess the potential environmental impacts of proposed major federal actions before allowing them to proceed. Agencies are not required to reject projects that might worsen climate change — only to examine and report the impacts.
The Trump administration had freed the government from considering the ways in which proposed new dams or pipelines, for example, might increase emissions of greenhouse gases like carbon dioxide and methane that are warming the planet to dangerous levels. It required agencies to analyze only “reasonably foreseeable” impacts. Mr. Trump said the change would eliminate “mountains and mountains of red tape” that he said had delayed projects across the country.
Under the changes announced Tuesday, agencies would have to consider the direct, indirect and cumulative impacts of a decision — including the effect a new project would have on neighborhoods already burdened by pollution.
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Thawing permafrost. Climate scientists, policy experts and environmental justice advocates announced a $41 million project aimed at assessing the contribution of thawing permafrost to global warming. The project is financed by private donors, including the philanthropist MacKenzie Scott.
The administration’s changes also encourage agencies to study alternatives to projects that are opposed by local communities, and it says the law’s requirements are “a floor, rather than a ceiling” when it comes to environmental reviews.
Republicans and some business groups are hostile to the changes, arguing that additional reviews would delay the development of badly needed infrastructure.
The American Road and Transportation Builders Association, a trade organization, wrote in comments to the Council on Environmental Quality that federal reviews for many transportation projects take five to seven years, with some lasting as long as 14 years. The new rule, it argued, would make matters even worse.