Nepal has never burned much coal or drilled for oil. Its share of global greenhouse gas emissions is negligible. Yet on Aug. 26, a torrent swept away villages, engulfed people and damaged roads and hydropower plants near the Nepal-China border. The death toll has crossed 1,450, and thousands are still missing. Four weeks later, Nepal's Prime Minister Balendra Shah stood before the U.N. General Assembly and asked a stark question: Has the world truly heard this warning, or simply filed it away with the rest? Shah's address rested on a firm premise: Nepal is not a bystander to a remote emergency but its barometer, and the instruments are flashing red. The floods that ravaged the Bhotekoshi and Trishuli valleys ignored borders and spilled downstream into India. His speech asked the world to see mountain regions as the front lines of a shared crisis, not isolated frontiers. The Himalayas hold the largest store of ice outside the poles, and more than 2 billion people rely on their rivers for water, food and power. When permafrost thaws and mountain faces fracture, a landslide triggers a delu