New Delhi, Feb. 18 -- Human societies have long found ingenious ways to cope with extreme weather; and India is no exception. The ancient Kallanai dam in southern India, for example, built to divert the Kaveri River for irrigation, sustained fertile delta farming for centuries. The stepwells of western India-subterranean reservoirs that stored water-offered relief from extreme heat and helped local communities endure long dry seasons.

The world today spends about $190 billion a year on climate adaptation through 20 proven cost- effective measures-ranging from sea dikes to air-conditioning-to protect against heat, drought, wildfire and flooding, finds a McKinsey Global Institute research study, 'Advancing Adaptation: Mapping Costs from Co...