Josh Siegel of the Washington Examiner explains the convoluted details of U.S. involvement with the Paris deal on climate change.

No matter the result of the presidential election, one thing will be immediately clear: The United States will become the only country in the world not a part of the Paris climate change agreement.

President Trump rejected the global climate pact, negotiated in the Obama administration, during a Rose Garden ceremony in June 2017. But he can’t officially leave it until Nov. 4, the day after the election.

That’s the one-year anniversary of Trump’s State Department submitting paperwork to the United Nations notifying of its intent to withdraw, setting in motion a 12-month waiting period to get out officially as required under the Paris deal’s terms.

Despite those logistics, the ultimate fate of the U.S. relationship with the Paris pact hinges on the outcome of the election.

If he were to win, Joe Biden has pledged to reenter the agreement on day one of his presidency, Jan. 20, a move that would make the lame-duck period during which the U.S. will be absent from the pact a forgotten footnote.

“If Biden wins, the gap is kind of meaningless because people will know the U.S. is right back in and will treat the Trump years like a bad memory,” said Alden Meyer, U.S. manager of the International Climate Politics Hub.

Trump is unlikely to reengage with the Paris agreement, or prioritize mitigating climate change more broadly, if he were to win a second term. Trump has complained the Obama administration’s ambition to cut emissions was too much compared to other major polluters such as China and India. Under the Paris agreement, all of the nations of the world set their own nonbinding targets for reducing carbon emissions.

“There’s not going to be a reversal of that decision. I can’t imagine the president changing his mind on Paris by himself,” said George David Banks, Trump’s former international energy adviser. …