If cosmic justice prevails, Donald J. Trump could live to see the Atlantic Ocean roll through his beloved Mar-a-Lago resort from the sea to the intracoastal waterway. His children almost certainly will.

The plush country club is built upon what geologists call a barrier beach — essentially a sandbar between the ocean and the bay. Already, water pools form on parts of the property during coastal storms and extreme high tides, as sea levels driven by global warming rise a bit faster every year.

OPINION

Within 30 years, climatologists estimate, Mar-a-Lago could be vulnerable to flooding as many as 210 days a year. It’s a growing problem across South Florida. Even mighty Donald cannot command the sea.

Indeed, disaster could come as early as this year’s North Atlantic hurricane season, predicted to be an active one. Experts calculate that the storm surge from even a Category 2 storm could leave parts of the “Southern White House” property under a foot or more of water. Maybe the president can change it from a golfing to a surfing resort.

Perhaps he might then get around to appointing somebody to head FEMA, the Federal Emergency Management Agency, which he hasn’t done — too busy conducting a one-sided Twitter feud with the mayor of London. He’s also named no U.S. Attorneys and only a small handful of ambassadors.

But then, hey, who needs diplomats? Trump can insult and belittle America’s strongest allies entirely on his own.

Evidently, Trump thought sophisticates were laughing at him in Europe and became determined to make them pay the price in symbolic gestures. Them and Barack Obama, whose negotiation of the Paris Climate Accords was rightly seen as the diplomatic high point of his presidency — not because it bound the United States to what Trump falsely called a “draconian” regulatory regime, but because China, India and other developing countries agreed to participate for the first time.

Why falsely? Because everything in the Paris agreement is strictly voluntary. There are no penalties and no enforcement mechanisms in the agreement whatsoever. Each nation remains free to set its own goals for greenhouse gas abatement and to change them at any time.

It’s a cooperative, not a coercive thing.

So if Trump had merely chosen to cancel Obama’s Power Plan to please Koch Industries and other industrial polluters, all he had to do was say so. Issue an executive order countermanding President Obama’s and bingo, it’s done.

Sure, China’s free to build all the coal-fired electrical plants it wants, although it’s canceled more than 100 of the damn things. But then, contrary to Trump, the United States is also free to do so, although hardly anybody wants to.

Hillary Clinton may have been smug and impolitic when she said during the campaign that her climate policies would “put a lot of coal miners and coal companies out of business.” But it’s going to happen anyway.

Coal is too expensive and dirty, a 20th-century technology that pollutes the air and fouls the water. Natural gas and solar are winning in the marketplace everywhere but Wyoming and West Virginia.

So it follows that no, the Paris Agreement isn’t up for renegotiation. Nor was it imposed by France, merely negotiated there. Anyway, what would Trump demand? The same free hand he’s already got? That $100 billion Green Climate Fund Trump railed against actually contains $10.3 billion — a comparative pittance. Nor does America’s share come out of anti-terror funds.

Former Secretary of State John Kerry may have put it best: “He’s going to go out and find a better deal? . . . I mean, that’s like O.J. Simpson saying he’s going to go out and find the real killer.”

“Meanwhile, the earth is still warming,” writes Politico’s Michael Grunwald, “the polar ice caps are still melting, and the seas are still rising, heedless of the inspiring words committed to paper in Paris, and just as heedless of a noisy American politician’s decision to reject them … Trump can call global warming a hoax, but 2014 was nevertheless the hottest year on record, until it was displaced by 2015, which was overtaken by 2016.”

And if 2017 were to come in a little cooler, industry-funded denialists would call the science disproved. Because if tomorrow’s cooler than today, there will be no summer. It’s the climatological equivalent of “creation-science,” based upon the screwball belief that researchers worldwide have concocted a conspiratorial hoax. “The concept of global warming,” Trump tweeted in 2012, “was created by and for the Chinese in order to make U.S. manufacturing non-competitive.”

Which is ultimately what this is all about: an attack on expertise by a politician who basically ran against sophistication. An assault on diplomacy by a leader who has defiantly abdicated his role as “leader of the free world.”

In short, Trump’s actions have gained him nothing while weakening the United States in what he mistakenly sees as a show of strength.

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