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.

U.S. withdrawal from the world's primary climate pact will have a bigger impact - in the U.S. and globally - than the country's first retreat in 2017, analysts and diplomats told Reuters.