In a city built on islands and inlets, the wind off the Øresund smells faintly of salt and cycling grease. Copenhagen’s answer to climate change is not a single icon so much as a choreography: heat the homes with shared pipes, cool the business core with seawater, turn rainstorms into parks, and turn trash into watts—then capture the carbon on the way out. The system hums in buried mains and pump rooms, but its logic is legible on the street.