For a U.S. President Joe Biden, rejoining the Paris agreement would be almost as simple as signing an autograph. The hard part would be everything else.
With global warming already fueling wildfires, hurricanes and mass migrations, Biden would face the monumental task of decarbonizing the world’s biggest economy. And he would have to do it quickly at a time when China, the biggest emitter of greenhouse gases, is recasting itself as a climate leader and as the European Union ramps up its environmental ambitions. The stakes are high: Failure would not only erode global confidence in the U.S. but contribute further to the destabilization of the climate, with grave consequences for people and planet.