In equatorial Singapore, the late-afternoon thunderheads pile up like mountains, then dissolve into warm rain that runs from green roofs to canals and finally to the sea. The city’s response to climate change is not a single showpiece but an interlocking loop: cool the homes, power the water, harden the shores, and close the carbon cycle. The hum here is chilled water in buried pipes, biogas in co-digesters, and solar panels riding the reservoir’s skin. The strategy is small-state pragmatism at system scale.