By Mark Gongloff / Bloomberg Opinion

In 2023, the U.S. Supreme Court declared, contrary to established science and object permanence, that water ceases to exist when it goes underground and is therefore no longer subject to meddlesome environmental protections.

Frothing lefties like Justice Brett Kavanaugh warned the decision was a recipe for widespread pollution. This week, President Donald Trump’s Environmental Protection Agency agreed … with the Supreme Court.

The EPA’s announcement on Wednesday that it would find the narrowest possible definition of the word “water” for regulatory purposes was just one of dozens of ways it plans to attack environmental protections during Trump’s second term in office. Supposedly meant to spark some sort of “Great American Comeback,” these actions would mainly bring back an era of poisoned skies and waters while hurting the very economy they’re supposed to help.

“Today is the greatest day of deregulation our nation has seen,” EPA Administrator Lee Zeldin bragged in a news release. “We are driving a dagger straight into the heart of the climate change religion to drive down cost of living for American families, unleash American energy, bring auto jobs back to the U.S. and more.”

Wherever the EPA is aiming its dagger, its ultimate victim will be the environment. If it succeeds in gutting the targeted rules, then oil and gas producers, utilities, chemical plants, factories and other major polluters will have freer rein to pump mercury, arsenic and other toxins into our air and water. They’ll be able to spew more of the greenhouse gases that are heating up the planet, creating climate chaos and driving up insurance costs for those same American families. Coal-burning plants and gasoline-guzzling cars will stay in service for much longer, making the climate problem even worse.

During his Senate confirmation hearings, Zeldin, a former New York congressman, admitted climate change was “real,” echoing the vast majority of scientists and most American voters. Now that he’s in the job, the mask is off and climate action has been downgraded to a “religion,” with Zeldin in the vanguard of the Trump administration’s crusade against it.

Along with his assault on environmental rules, Zeldin has asked Trump to overturn the government’s key 2009 finding that greenhouse gases endanger the public and are thus subject to EPA regulation. He has revoked $20 billion in grants issued under the Inflation Reduction Act, the biggest climate law in U.S. history. He has asked Congress to take away California’s right to sets its own automobile-emissions standards. He ended the EPA’s environmental justice unit, meant to protect Americans most vulnerable to pollution and natural disasters. He has vowed to slash his agency’s budget by at least 65 percent.

Hopefully, the slow-grinding gears of bureaucracy will soften or at least delay some of these blows. As Bloomberg News notes, Zeldin doesn’t have a big red MORE POLLUTION button in his office. His agency will have to rewrite these rules, subject them to public opinion and fight the already mounting court challenges from local governments and environmental groups. The process could take years, particularly given the sheer number of rules in question and a rapidly diminishing number of employees available to rewrite them.

As for overturning that 2009 “endangerment” finding, the EPA will have to conjure up some scientific evidence to disprove that greenhouse gases are harming the environment. Good luck with that. Otherwise, it might be tough to convince even the Supreme Court, which decided in 2011 that people couldn’t sue polluters over greenhouse gases because it’s the EPA’s job to regulate them. Project 2025 wants to turn back the clock on that one, but many oil and gas companies probably don’t.

In fact, for all of Zeldin’s big talk about freeing business from the shackles of woke regulation, most businesses benefit from predictable rules, even if they don’t always like them. How many will overhaul their operations in anticipation of a regulatory regime that could take much of Trump’s term to develop and still be overturned if and when an environmentalist next takes the White House in an even hotter, more chaotic and polluted future? Will Detroit automakers ditch electric vehicles after years of gearing up to make them, wasting $200 billion in investment and surrendering this growing market to China, as my Bloomberg Opinion colleague Liam Denning has noted?

Still, every move the EPA makes against climate action is energy pushing in exactly the wrong direction at the worst possible time. Cutting greenhouse-gas emissions and limiting global heating to merely catastrophic levels will be that much harder as a result. Rather than healing the American economy as Trump claims, this will deliver another self-inflicted wound (see also tariffs, pointless).

A new study by the consulting firm BCG finds that letting the planet heat to 3 degrees Celsius above preindustrial averages could erase up to a third of global economic output by the end of the century (more, if tipping points accelerate heating). A separate National Bureau of Economic Research study last year suggested every 1C of heating shaves 12 percent from global GDP. Already the U.S. is experiencing an insurance crisis because of the rising costs of climate-fueled natural disasters such as wildfires and floods. Environmental protection is economic protection. We’re about to learn that the hard way.

Mark Gongloff is a Bloomberg Opinion editor and columnist covering climate change. He previously worked for Fortune.com, the Huffington Post and the Wall Street Journal.