The mountains of the Hindu Kush Himalaya (HKH) are called the “water towers of Asia,” as they are the source of 10 major Asian river systems: the Amu Darya, Indus, Ganges, Brahmaputra (Yarlungtsanpo), Irrawaddy, Salween (Nu), Mekong (Lancang), Yangtse (Jinsha), Yellow River (Huanghe), and Tarim (Dayan). The HKH is also known as the third pole, as it has the highest concentration of snow cover, glaciers, and permafrost outside the polar regions. The HKH supplies freshwater and other ecosystem services to approximately 1.9 billion people – approximately a quarter of the world’s population – living downstream. Along with providing water for agriculture, the mountain systems also provide food and energy. Increasingly skewed, erratic, and rapid development have raised challenges in meeting water, food, and energy demands in all eight countries in the region.