Each year, enough water flows from the Tibetan plateau to fill the entire Yellow River, the mother river of Chinese civilization.
Today in China alone, 300 million people depend on water from the Tibetan plateau.
With its profound effect on Asia's weather and water systems, the Tibetan plateau helps to sustain almost half the world's population.
For the moment, at least. Close to the summit of Mount Everest, a forest of ice once covered much of the area. But now, thanks to climate change, much of it has gone.
Within the next 30 years it's predicted that 80% of the Tibetan glaciers could disappear.
In many ways, Tibet's fragile environment is the barometer of our world. What happens to it today, in time, will affect us all.