In our collective imagination, the Himalayas -- the roof of the world -- are an archetype: glistening white, distant, even otherworldly. Climbing them is proof of humanity's daring, courage and drive. And yet, despite rising 6,993 metres above sea level, the summit of Mount Machapuchare in central Nepal resembled a black rock pyramid this winter, devoid of ice and snow. Glaciers near Mount Everest have turned into large lakes.
More than a tourist attraction or a place for high adventure, the Himalayas play a crucial role in regulating the planet's climate. They are also the source of fresh water for billions of people and for the region's rich (though increasingly degraded) ecosystems. As a result, rising temperatures and glacial melt are having far-reaching consequences that already pose grave risks to humanity.
The Tibetan Plateau is at the centre of High Mountain Asia, an area known as the Third Pole -- the Earth's third largest store of frozen water, after Antarctica and the Arctic. The region has about 15,000 glaciers that cover almost 100,000 square kilometres of High Mountain Asia, containing 3,000-4,700 cubic kilometres of ice. The glaciers supply the Amu Darya, Brahmaputra, Ganges, Indus, Irrawaddy, Mekong, Salween, Tarim, Yangtze and Yellow river basins. The Hindu Kush Himalayas stretch across 3,500 kilometres and span India, Nepal, China, Bhutan, Pakistan, Afghanistan, Bangladesh and Myanmar.
