President Trump got a step closer to pulling America out of the Paris Climate Agreement by sending a withdrawal letter to the United Nations, Secretary of State Mike Pompeo announced in a statement Monday.

Driving the news: While Trump indicated this intention in June 2017, today marks the first day his administration could begin the formal process, which will be completed on Nov. 4, 2020 — a day after the 2020 presidential election.

Why it matters: While today is more procedural than symbolic in nature, the U.S. beginning the exit process is likely to further dampen the 2015 climate deal's aspirations and remove any slim chance that Trump would ever re-engage on the matter, like he suggested in 2017 he would be willing to.

What they're saying: A White House spokesman didn't comment beyond writing by email that "the president has already announced that the U.S. is not a part of the Paris Climate Agreement."

Pompeo wrote on Twitter: "Today we begin the formal process of withdrawing from the Paris Agreement. The U.S. is proud of our record as a world leader in reducing all emissions, fostering resilience, growing our economy, and ensuring energy for our citizens. Ours is a realistic and pragmatic model."

The big picture: The U.S. is the only country in the world not to support the accord, whose goal is to drastically slash greenhouse gas emissions in the coming decades to keep Earth's global temperature from rising 2°C within this century.

Where it stands: The planet's temperature has already increased about 0.8°C since 1880, according to NASA, and the world isn't even close to meeting the Paris goals. In fact, trends are going in the opposite direction. Global carbon dioxide emissions just reached an all-time high.

Reality check: In a Rose Garden speech in June 2017, Trump criticized the accord as a bad deal for America because it allowed China to continue increasing its emissions and because it would hurt the bottom lines of U.S. businesses. But most big companies — even oil producers — say they support the accord.

What we're watching: If a Democrat wins the White House in 2020, he or she would have to submit a letter to rejoin the accord, at which point there is a 30-day delay. The U.S. could then be back into the agreement as soon as Feb. 21, 2021.

Go deeper: Paris + 2: Climate jolted faster than projected