New climate envoy John Kerry is making clear that the United States isn’t just back in the fight to slow climate change, but that it plans to play a driving role again. Kerry is envoy for climate change and national security in President Joe Biden’s administration. He is working to make a long-term success out of the Paris climate accord he helped negotiate during the Obama administration. President Donald Trump rejected the U.N. climate accord and other Obama-era efforts against climate change. Kerry is talking to global leaders, U.S. mayors and others from his Boston home, making clear he plans to push for faster cuts of climate-damaging fossil fuel emissions.