The Paris agreement is a mostly voluntary climate pact originally written to both try to reduce warming and withstand the changing political winds in the U.S.

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.

The president on Monday announced his intention to withdraw the country, for the second time, from the global emissions reduction pact.