US Paris climate pact exit, vote may dictate how world warms

The United States is out of the Paris climate agreement on the day after the presidential election. Experts say the outcome will determine to some degree just how hot and nasty the world will get in the future. The two presidential candidates have stark differences on fighting human-caused climate change. Joe Biden has promised to return the U.S. to the agreement, while Donald Trump took the country out of the 189-nation accord. Experts say the U.S., the second biggest carbon polluting nation, w