BILLINGS, Mont. (AP) — Down to its final weeks, the Trump administration is working to push through dozens of environmental rollbacks that could weaken century-old protections for migratory birds, expand Arctic drilling and cripple future regulation of public health threats.

The pending changes, which benefit oil and gas and other industries, deepen the challenges for President-elect Joe Biden, who made restoring and advancing protections for the environment, climate and public health a core piece of his campaign.

“We’re going to see a real scorched-earth effort here at the tail end of the administration,” said Brian Rutledge, a vice president at the National Audubon Society.

The proposed changes cap four years of unprecedented environmental deregulation by President Donald Trump, whose administration has worked to fundamentally change how federal agencies apply and enforce the Clean Water Act, Clean Air Act and other protections.

Most of the changes are expected to sail through the approval process, which includes the White House releasing the final version and publication in the Federal Register.

Some decisions, if they go into effect, will be easy for Biden to simply reverse. He already has pledged to return the United States to the Paris climate accord as a first step in his own $2 trillion climate plan. But he faces years of work in court and within agencies to repair major Trump cuts to the nation’s framework of environmental protections.

One change that Trump wants to push through would restrict criminal prosecution for industries responsible for the deaths of the nation’s migratory birds. Hawks and other birds that migrate through the central U.S. to nesting grounds on the Great Plains navigate deadly threats — from electrocution on power lines, to wind turbines that knock them from the air and oil field waste pits where landing birds perish in toxic water.

Right now, the Migratory Bird Treaty Act of 1918 is a vital tool for protecting more than 1,000 species of birds including hawks and other birds of prey. Federal prosecutors use the act to recover damages, including $100 million from BP for its 2010 oil-rig spill into the Gulf of Mexico, which killed more than 100,000 seabirds.

But the Trump administration wants to make sure companies face no criminal liability for such preventable, unintentional deaths.

Federal officials advanced the bird treaty changes to the White House, one of the final steps before adoption, two days after Biden was called by the Associated Press as the winner of the presidential race.

For industry, “that’s an important one,” said Rachel Jones, vice president of the National Association of Manufacturers. Jones lobbied for the changes in the Migratory Bird Treaty Act at a meeting last year between private-sector representatives and staff from the White House and Interior Department. “It really matters in relation to the infrastructure we need for a modern society.”

Earlier moves by the Trump administration, which are now facing court challenges, remove protections for millions of miles of waterways and wetlands, narrow protections for wildlife species facing extinction, and open more of the hundreds of millions of acres of public land to oil and gas drilling.

Asked about the push now, as Trump and many of his supporters continue to deny his election loss. Environmental Protection Agency spokesman James Hewitt said, “EPA continues to advance this administration’s commitment to meaningful environmental progress while moving forward with our regulatory reform agenda.”

Pushing to get new rules on the books before the end of a president’s term is not unusual — former Presidents Barack Obama and George W. Bush both did it, said Cary Coglianese, an expert on administrative law and rule-making at the University of Pennsylvania Carey Law School.

Obama agency heads, after the 2016 Trump victory, pushed through rules that sought to protect funding for Planned Parenthood and toughen pollution rules on the oil and gas industries, among others.

But environmentalists and some former federal officials said the actions being taken in Trump’s final days reflect a pro-industry agenda taken to the extreme, in disregard for imperiled wildlife, climate change and damage to human health from air pollution.

“What we’re seeing at the end is what we’ve seen all along, which is a fealty to private interests over public interests,” said David Hayes, former deputy secretary of the Interior Department under Obama and now adjunct professor at the New York University School of Law. “They seem intent on finalizing these as a kind of ideological point.”

Many of the final rollbacks still pending under the Trump administration have significant implications for oil and gas companies. That includes the administration’s steps this week toward a sale of energy leases in the Arctic National Wildlife Refuge.

Monday’s announcement of upcoming sale drew rebukes from environmentalists and Democrats in Congress.

Brett Hartl with the Center for Biological Diversity said backers of drilling are playing the long game and know that another Republican administration favorable to drilling will come along eventually.

“Any time you’ve officially got an area under lease … it makes it harder to keep the land protected in the long run,” Hartl said.

Another proposal that arrived at the White House last week would set emissions standards for small but dangerous particles of pollution emitted by refineries and other industrial sources. Other changes would allow more drilling and mining on thousands of square miles of public lands around New Mexico’s Chaco Canyon National Historical Park and deep in the Alaska wilderness.

The Trump administration from its first days pursued American “energy dominance,” in which imported oil would no longer be needed and U.S. companies would produce a surplus of fuels that could be sold to other countries.

Finalizing the pending changes is critical to maintaining the nation’s “energy leadership,” said American Petroleum Institute senior vice president Frank Macchiarola. For the oil and gas industry, he said, the opening of the Arctic refuge to drilling was long overdue and would provide jobs and needed revenue for the state of Alaska.

But people are looking to two pending Senate contests in Georgia for insight into how easily any of his administration’s last-minute changes can be undone.

If Democrats win both, they’ll control the Senate and the House and will be in position to invoke the Congressional Review Act, which allows Congress to strike down newly approved regulations. Otherwise, outside parties could sue or the Biden administration would have to undertake the often lengthy process of reversing changes that are fully enacted before Trump leaves office.

“Regulations are not like diamonds,” said Coglianese, the Penn law professor. “They don’t last forever.”