Tibetan Plateau

The Tibetan Plateau is the highest and most extensive upland on Earth, a vast tableland averaging some 4,500 metres above sea level - higher than most of the world's mountains - spread across roughly 2.5 million square kilometres of Central Asia. Ringed by the planet's greatest ranges, including the Himalaya to the south, it is fittingly called the Roof of the World. Its thin air, fierce cold, and immense scale shape the climate of an entire hemisphere and feed the rivers on which billions depend.

The plateau rose, and is still rising, from the head-on collision of the Indian and Eurasian plates over the past fifty million years, a slow-motion crash that thickened the crust to nearly twice its normal depth. So massive is the uplift that it deflects the jet stream and powers the Asian monsoon, while its bright snows and high albedo influence weather far beyond its rim. From its glaciers and lakes flow many of Asia's great rivers - the Yangtze, Yellow, Mekong, Brahmaputra, Indus, and Ganges among them - making it the water tower of the continent.

For centuries the plateau was the heartland of Tibetan civilisation, a society of nomadic herders and Buddhist monasteries adapted over millennia to extreme altitude through genetic changes that aid survival in low oxygen. Today it lies largely within China's Tibet Autonomous Region and neighbouring provinces, a focus of cultural and political tension as well as of scientific concern: its glaciers are melting, its permafrost thawing, and the security of Asia's rivers hangs on its fate.

• China
  The world's most populous nation reborn as an economic superpower located in
• Asia
  Earth's largest and most populous continent located on