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.

President Donald Trump on his first day in office again withdrew the U.S. from a landmark global pact to fight climate change. So what is the Paris Agreement? And what happens to it now?

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.