The United States’ second exit from the Paris Agreement wasn’t unexpected. Even before he was reelected, now-president Donald Trump had promised for months that he would pull the country out of the United Nations pact to limit global warming: the Paris climate “ rip-off ,” as he called it.

Trump's executive order called for an immediate withdrawal from the Paris Agreement. The agreement requires one year notice, but there's room for interpretation.

It is a pact that is part of the United Nations Framework Convention on Climate Change, which started in 1992 with the Rio Earth Summit. Technically, the Paris agreement itself is not a treaty so its adoption by America did not require U.S. Senate approval.