CLIMATE CHANGES

LAST FALL, MIAMI-DADE COUNTY COMMITTED to eliminating its entire carbon footprint within three decades. It was an ambitious target, but also a symbolic one: a private utility company, Florida Power and Light, provides the region’s electricity and operates free of county oversight. “We had no control,” says Jim Murley, the county’s chief resilience officer. But then something seemingly miraculous happened: in June, the utility said it would cut emissions on its own—and even faster than county officials had promised. “We were just stunned,” says Murley.

For years, activists, politicians, and academics have tried to transition the global economy away from fossil fuels, with only mixed results. Overnight, it’s as if everything has changed, and for the first time in a long time, there’s a glimmer of hope.