WASHINGTON — President Trump sharply changed the federal government’s approach to the environment on Tuesday as he cleared the way for two major oil pipelines that had been blocked, and set in motion a plan to curb regulations that slow other building projects.
In his latest moves to dismantle the legacy of his predecessor, Mr. Trump resurrected the Keystone XL pipeline that had stirred years of debate, and expedited another pipeline in the Dakotas that had become a major flash point for Native Americans. He also signed a directive ordering an end to protracted environmental reviews.
“I am, to a large extent, an environmentalist, I believe in it,” Mr. Trump said during a meeting with auto industry executives. “But it’s out of control, and we’re going to make it a very short process. And we’re going to either give you your permits, or we’re not going to give you your permits. But you’re going to know very quickly. And generally speaking, we’re going to be giving you your permits.”
The decisions expanded an effort to unravel much of the policy structure left by former President Barack Obama, who made fighting climate change a central priority. Just a day earlier, Mr. Trump formally abandoned the Trans-Pacific Partnership, an ambitious 12-nation trade pact negotiated by Mr. Obama.
In his opening days in office, Mr. Trump has also modified or reversed Mr. Obama’s policies on health care, abortion and housing while ordering a freeze of any pending regulations left behind by the former administration.
The pipelines were more about symbol than substance but generated enormous passion on both sides of the debate. Mr. Obama rejected the proposed Keystone pipeline in 2015, arguing that it would undercut American leadership in curbing the reliance on carbon energy. The Army sidetracked the Dakota Access pipeline in North Dakota last month in the waning days of the Obama administration.
Environmental activists quickly denounced Mr. Trump’s decisions. “Donald Trump has been in office for four days, and he’s already proving to be the dangerous threat to our climate we feared he would be,” said Michael Brune, the executive director of the Sierra Club.
Mr. Trump made clear on the campaign trail that he saw Mr. Obama’s environmental policies as a threat to the economy and dismissed climate change as a hoax perpetrated by China. Myron Ebell, a climate change denier who headed Mr. Trump’s Environmental Protection Agency transition team, has drafted a 50-page blueprint for how he could eliminate Mr. Obama’s climate change policies. “It is designed to implement all of the president’s campaign trail promises — every single one,” Mr. Ebell said this week in an interview.