For millions of years, monsoonal winds have cycled between Asia’s tropical seas and the Tibetan Plateau, delivering snow to its high-altitude mountains and rains to the plains below them. The melting snow and summer rains combine to create a system of rivers that fan out from the mountains, delivering water and fertile soil to East, Southeast and South Asia.
Known as the Great Himalayan Watershed (GHW), this hydrological phenomenon has created richly diverse ecosystems and the right conditions for some of the world’s earliest agricultural and urban centres. The GHW encompasses most of Asia’s rivers—today around 45% of the world’s population depends on the watershed and it is home to many significant manufacturing centres and trade networks. Despite this, the GHW has received little public or political attention.
Increasing attention is now being paid to the watershed’s degraded state. Scientists, environmentalists and locals are particularly concerned about its glaciated headwaters and its deltas. Both are experiencing accelerated climate change and biodiversity loss.