The U.S. officially rejoins the Paris Climate Agreement Friday after President Joe Biden signed an Executive Order on his first day in office (Jan 20). The order comes into effect Friday. Donald Trump formally pulled out of the agreement on November 4, 2020. Later this year, the Biden administration will submit a new official commitment pledging reductions in emissions. Biden and his climate envoy John Kerry will host a climate leaders’ summit on Earth Day, April 22.