President Donald Trump announces his decision that the United States will withdraw from the landmark Paris Climate Agreement, in the Rose Garden of the White House on June 1, 2017. REUTERS/Kevin Lamarque While President Donald Trump announced Thursday that he was pulling the US out of the landmark Paris climate agreement, it will take until the day after the next presidential election for the US to fully exit the pact.

The Paris agreement, which 195 nations signed in December 2015, set the global goal to keep the planet from warming by more than 1.5 degrees Celsius above preindustrial levels — a threshold that scientists say could keep the planet from launching into a tailspin of irreversible consequences, from unpredictable superstorms to crippling heat waves.

And with so many moving parts, the accord has quite a few rules.

Beyond signing the overall agreement, each country also submitted a climate-action plan laying out how it would adopt clean energy and phase out fossil fuels. This allowed each nation to individualize and edit their commitments, adding flexibility to the Paris agreement so that it could bend without breaking.

The US's plan, which the Obama administration submitted in March 2015, set the goal of reducing greenhouse gas emissions by 26% to 28% by 2025. The baseline level this reduction is measured against is 2005, when the US emitted 6,132 million metric tons of carbon dioxide.

Because of the way the agreement was designed, it will take years for the US to fully exit it. According to its rules, the earliest Trump could give written notice of the US's withdrawal would be November 2019, and the US wouldn't officially exit it until November 4, 2020 — the day after the next presidential election.

While Obama agreed to the Paris accord through executive action, the US Senate approved the original treaty that was the UN's basis of the overall Paris agreement back when George H.W. Bush was president in 1992.

Exiting the overall UN agreement would take a year, but would likely require Senate approval. Trump didn't indicate that he wanted to abandon the overall treaty.

Of course, Trump also said he was willing to renegotiate the agreement.

"I'm willing to immediately work with Democratic leaders to either negotiate our way back into Paris under the terms that are fair to the United States and its workers, or to negotiate a new deal that protects our country and its taxpayers," he said Thursday.