The rapidly retreating South Annapurna glacier in the Annapurna sanctuary, Nepalese Himalayas. The retreating glacier has left a huge empty chasm that until recent times was filled with ice. All of the Himalaya's glaciers are retreating rapidly due to climate change. The glaciers feed many of Asia's largest rivers that billions of people rely on for water. As these reservoirs disappear, it will have disastrous consequences for water supplies.