The Tibetan plateau is being destroyed by rising temperatures, excess livestock and plagues of insects and rodents – and the changes are having a profound impact on the world’s ecology.
Without its grasslands the high plateau is less able to absorb moisture and more likely to radiate heat and this is accelerating climate change. Partly because of this, the Tibetan mountains have warmed two to three times faster than the global average and the permafrost and glaciers are melting.
To make matters worse, the towering Kunlun, Himalayan and Karakorum ranges that surround the plateau act as a chimney for water vapour, which has a stronger greenhouse gas effect than carbon dioxide. The water vapour is mixed with pollution, dust and black carbon from northern India and elsewhere that spreads a brown cloud across much of the Eurasian landmass. This is convected high into the stratosphere by the Tibetan "chimney".
When permafrost melts it can also release methane, another powerful greenhouse gas. Xiao Ziniu, the director general of the Beijing climate centre, says Tibet’s climate is the most sensitive in Asia and influences the globe.
On top of all this, rodent numbers have increased dramatically in 10 years because their natural predators – hawks, eagles and leopards – have been hunted close to extinction. The growing population of pika, gerbils, mice and other rodents is degrading the land because they burrow into the soil and eat grass roots. Zoologists say this highlights how ecosystems can quickly move out of balance.
Yang Yong, a Chinese explorer and environmental activist, told the Guardian that "People have not paid enough attention to the Tibetan plateau. They call it the Third Pole but actually it is more important than the Arctic or Antarctic because it is closer to human communities. This area needs a great deal more research. The changes to glaciers and grasslands are very fast. The desertification of the grassland is a very evident phenomenon on the plateau. It’s a reaction by a sensitive ecosystem that will precede similar reactions elsewhere."