Tuesday began with news that the Trump Administration had imposed a comprehensive gag order on employees of the Environmental Protection Agency. According to a leaked memo, “no press releases,” “no blog messages,” and “no social media will be going out,” and “no new content can be placed on any website” until further notice—perhaps an attempt to camouflage the other big E.P.A. announcement, which was that the agency’s grants and contracts had been temporarily frozen, effectively halting its work. Then, at nine o’clock, the President had breakfast with a group of beaming auto executives. Trump told them that he was “to a large extent an environmentalist,” but apparently his long participation in that movement had persuaded him that “environmentalism is out of control.” The last time Detroit’s C.E.O.s came to the White House, in 2011, President Obama got them to agree, grudgingly, to increase average fuel economy to 54.5 miles per gallon, a pledge they now hope to recant. The day went on. Just before noon—surrounded by his increasingly familiar cast of white guys in suits—Trump signed an executive order expediting approvals for the Keystone and Dakota Access pipelines, thus overturning perhaps the two biggest environmental victories of the Obama years, both of which the advocacy organization I helped found, 350.org, fought for vigorously.

There is, in other words, a new day dawning, and we’re sure as hell not going to use any of that sunlight for energy. Instead, it’s clear that we’re about to witness the steady demolition, or attempted demolition, of the environmental protections that have been put in place over the past five decades. Another leaked memo, released on Monday and attributed to Myron Ebell, the veteran climate-change denier overseeing Trump’s E.P.A. transition team, made clear some of the Administration’s first priorities: stopping Obama’s Clean Power Plan, which uses the Clean Air Act to regulate power plants; revising the rules on development in crucial wetlands; and even such granular tasks as reining in efforts to halt the rampant pollution of Chesapeake Bay. The full list, I imagine, will stretch on and on. The nascent effort to prevent leakage from fracking wells, for instance, will likely be abandoned, meaning that we’ll continue to spew methane as well as carbon dioxide into the atmosphere. At the Department of the Interior, they’re getting ready to start leasing coal from public lands again; at State, Rex Tillerson says he wants a “seat at the table” in international climate negotiations, but probably won’t push them forward. The drive to free up polluters is so strong and ingrained that it overrides even the usual Republican commitment to states’ rights: Scott Pruitt, who sued the E.P.A. fourteen times before being named to head it, ominously said at his confirmation hearing that he couldn’t promise California would continue to receive the waiver that allows it to set its own vehicle-emissions standards.

“You say you’re going to review it?” Senator Ed Markey, of Massachusetts, asked him.

“Yes, senator,” Pruitt said.

“When you say ‘review,’ I hear ‘undo,’ ” Markey said.

There’s not the slightest evidence that Americans want laxer environmental laws. A poll released last week showed that nearly two-thirds of Americans would prefer that the E.P.A.’s powers be preserved or strengthened. Solar power, meanwhile, polls somewhere in the neighborhood of ice cream among Democrats, Independents, and Republicans alike. But the survey that counts in the Trump Administration is of plutocrats, and, as Jane Mayer demonstrated in her book “Dark Money,” the moguls of the right-wing funding network, whose disciples are now in place across the Cabinet, hate environmental regulation with a passion. We know some of them—the Koch brothers, for instance. But there is a whole league of cartoonish villains, including John Menard, Jr., the richest man in Wisconsin, whose company was once charged with labelling arsenic-tainted mulch as “ideal for playgrounds.” Having paid hundreds of millions in fines, these people paid tens of millions in campaign contributions, and now their bill has come due.

Against them stands reality, as a rogue employee of the National Park Service reminded us on Tuesday afternoon, defying another gag order by tweeting out climate data from the official Badlands National Park account. The reason we have environmental regulations is because, when we didn’t, the air was filthy and the water sour. Cleaning up our skies and our streams has been an enormous success in every way, including economically: any attempt to tally things like lost work days or visits to the emergency room shows that curbing pollution has huge returns on investment. (Just ask the Chinese, who are desperately trying to cobble together their own system of environmental protections.) As in so many other cases, the returns on deregulation will go to a handful of very wealthy Americans, and the cost will be spread across society, falling particularly hard on those who live near the highways and on the flood plains. Reality gets plainer every day on a planet that just saw the hottest year ever recorded, where sea ice is at an all-time low, and where California’s epic drought has suddenly given way to epic flooding. History will judge the timing of Trump’s crusade with special harshness—it is, you might say, a last-gasp effort.