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?

Trump’s day-one actions on energy come as climate change-fueled fires ravage Southern California, following the globe’s hottest year on record.

With the US out of the tent, the rest of the world can get on with climate action without Trump’s corrosive influence.