The new U.S. president and Congress are taking a hard look at environmental rules—none harder than a freshman U.S. representative whose new bill would “terminate the Environmental Protection Agency.”

Republicans have been known to threaten this from time to time, with the understanding that it was red meat for ideological or business interests with no real chance of success. “Everybody hates regulation,” said Republican Christine Todd Whitman, a former EPA administrator and New Jersey governor, “because it makes you either spend money or change behavior for a problem you may not see.”

This year, as we all know, is a little different.

Donald Trump has modulated his position on the EPA’s existence since the presidential campaign. And yet the concept that the preeminent guardian of clean air, soil, and water in the U.S. would go the way of the 20th century is now, if nothing else, no longer confined to the realm of fantasy.

Rule-of-thumb holds that once countries pollute their way into economic progress, they’ll pause for a second and check to see if they can still breathe the air and swim in the water. If not, they fix it. China is currently the leading example, with India coming up behind. There are fewer examples of nations unwinding national environmental efforts.

Internationally, the U.S. does pretty well when it comes to protecting its environment and doing its part to combat global climate change. It ranks 26th among 180 nations in the 2016 Environmental Performance Index, a collaboration of the World Economic Forum and Yale and Columbia University researchers. That’s just worse than Canada and a bit better than the Czech Republic.

The EPA sits at the forefront of that accomplishment (such as it is). The environmental laws passed under President Richard Nixon, who helped create the agency, have cleaned up the excesses of mid-century American industrialization. The statutes were written to anticipate new problems, too. While the Clean Air Act doesn’t address climate change—only a small group of scientists and far fewer (if any) politicians were aware of the question back then—the law is flexible enough to address new dangers.

In July 1970, the Republican president cobbled together the new agency from about a dozen offices distributed throughout the federal government. An additional dozen functions were reorganized into the National Oceanic and Atmospheric Administration, the biggest entity within the Department of Commerce. By creating the EPA, “I am making an exception to one of my own principles,” Nixon wrote. “That, as a matter of effective and orderly administration, additional new independent agencies normally should not be created.” But in this case, he said, there was just no better option.

That many EPA functions predate the agency is one element of the department’s complexity. “EPA is not an entity in the typical Washington agency sense,” said Bill Reilly, who was the agency’s administrator under Republican President George H.W. Bush. “It was established by President Nixon as an amalgamation of several different entities, from Interior and Agriculture and so forth,” he explained.

Undoing Nixon’s reorganization could be accomplished by a Trump executive order, Reilly said. But “what that does not take into account is that every statute I’m aware of specifically confers authority on the administrator of EPA to carry them out,” Reilly said. “And that’s true for air, water, safe drinking water, Superfund, toxics, ‘Tosca’ [the Toxic Substances Control Act, not the opera]—the whole gamut.”

Dismembering the EPA could require that Congress individually change 45 years of environmental statutes, a feat that would require an enormous amount of time, organization, and political capital.

Jeff Holmstead is a former EPA assistant administrator and now a partner at Bracewell LLC in Washington. Charged with the hypothetical (and extraordinarily unlikely) task of dismantling the agency, he zeroed in on the two dozen or so statutes that assign responsibilities to the EPA administrator. Most of these laws have “citizen suit provisions” that let Americans sue the agency for not doing its job. “You’d have a huge mess on your hands,” if environmentalists started suing a government official that no longer exists.
Shredding the EPA willy-nilly would also hamstring businesses, which rely on it for approval and permits. The most recent Congress demonstrated an expanded appetite for EPA work by amending Tosca to include permitting for existing (in addition to new) chemicals. “The chemical industry needs EPA to act,” Holmstead said.

Expect Scott Pruitt, Trump’s nominee to run the agency, to preside over an EPA that (a) continues to exist, and (b) sets to work undoing President Barack Obama’s Clean Power Plan, Clean Water Rule, and reopening carbon pollution rules for new coal plants.

“I would predict with great confidence that those three things will happen,” Holmstead said.

The selection of Pruitt, Oklahoma’s attorney general, has triggered protest among retired EPA staffers and people who would work for him if he’s confirmed. Environmentalists have made hay of Pruitt’s tenure in Oklahoma, where he joined more than a dozen lawsuits against the EPA and shuttered a unit focused on environmental protection. Until he’s confirmed, it’s unclear how Pruitt may lead the agency, although the New York Times had some reasoned insight.

The EPA’s Office of Public Affairs declined to comment for this story.

Americans still need environmental protection, Whitman warned. In 2013, the most recent year with complete data, 91,000 people died of causes related to bad air, almost three times the total deaths from car accidents. “This is real, people,” the former EPA administrator said in a Feb. 3 interview.

Whitman criticized Trump’s executive order requiring federal agencies to undo two regulations for every one they create. “It’s fine to want to go back and scrutinize all regulations and make sure that none have out lasted their usefulness,” she said. “But it’s got to be a thoughtful determination,” and not an arbitrary rules-trashing quota.