US president Donald Trump may or may not survive the fury he has unleashed after firing the FBI director who likely helped him get elected. But the decision he takes most likely next week on whether or not to stay in the Paris climate agreement could have far-reaching consequences regardless of Trump’s own future.

The US emits a sixth of the world’s net greenhouse gases. Even though the Paris agreement is not legally binding, pulling out of it opens the US to do what it wants without repercussions. Already Trump’s climate-denying staff has launched a full-scale attack on the regulations meant to help honor US’s contributions to reducing emissions. Though some of these attacks are unlikely to survive the courts, the uncertainty they create is enough of an excuse for the many actors, including the world’s most-polluting corporations, to halt their march towards a cleaner future. Such has been the harm in mere four months of his presidency that the EU’s former chief climate negotiator said this week that the Paris accord may be stronger without the US.

Within the White House, there are two factions. Steve Bannon, chief strategist, is leading the nationalist charge with EPA administrator Scott Pruitt to get Trump to pull out of the accord. Rex Tillerson, secretary of state, is leading the globalist charge with Ivanka Trump and Jared Kushner to remain. Reports suggest that Trump is leaning on Bannon’s side, but he may yet decide to downgrade US commitments and choose Tillerson’s side. A meeting with all these players to be held on May 9 was postponed, but it’s likely to happen next week before Trump leaves for his first foreign trip. In any case, he has to announce his decision before the G7 meeting at the end of the month.

The US pulling out could prove to be a great tragedy. Ever since the first United Nations climate talk in 1995, getting global agreement has been like walking the world’s most dangerous tightrope. Big emitters like India, Russia, and Saudi Arabia are just waiting for the slightest excuse to reversing their own stance. To be sure, the US leaving won’t doom climate progress. But it would almost certainly mean that we will go beyond a 2°C rise in global average temperature compared to pre-industrial period, and it’s a line that most scientists agree could lead to irreversible changes and devastating consequences.

The Paris agreement is the culmination of a long and arduous journey, and it stands testament to the fact that humanity can come together to deal with the greatest challenge it has faced so far. Rational arguments don’t sway Trump, but let’s hope he will come to realize that his actions on the climate are likely to earn him the worst legacy of all US presidents.