See Candidate Page Joe Biden, Climate, International, South Carolina Biden in South Carolina 2/24/20 Biden has now moved into talking about climate change, which he called the single most important issue. "On day one, I will rejoin the Paris Climate Accord. I will summon other nations to Washington in first 100 days and up the ante." #SC2020— Caitlin Byrd (@MaryCaitlinByrd) February 25, 2020