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Traces: Landscapes in Transition

The Tibetan Plateau spans an area five times the size of Spain and has an average elevation of 4500 metres. After the Antarctic and Arctic, the plateau has the third highest reserve of ice which has led scientists to call it the 'Third Pole', thus highlighting its significance to the earth's climate. Like the North Pole, the Tibetan Plateau has been warming much faster than the rest of the world over the past 50 years and of the 46,000 glaciers on the plateau, many are shrinking. The plateau's height gives these temperature changes great importance because its land mass rises so high into the earth's atmosphere that it regulates the Asian weather system, concocting the annual monsoonal rains and steering westerly wind currents as far as the Mediterranean. Its lakes, glaciers and wetlands act like a huge water tower for all of Asia, supporting about 1.4 billion people downstream.

Outside the window as we travel in an SUV with independent Chinese geologist and environmentalist Yang Yong are undulating hills covered in snow. He has been surveying the source of China's major rivers on the Tibetan Plateau for the past 30 years. He’s agreed for me to tag along on the segment of the trip where he revisits and monitors certain regions near the headwaters of the Yellow River in Madoi County where desertification has advanced significantly. Yang Yong’s goal, he says, is the gathering of scientific data on the Tibetan Plateau in order to better understand how best to protect and develop the 'Three River Source' National Nature Reserve or Sanjiangyuan in Chinese, an area roughly the size of Great Britain, from which headwaters of China’s three major rivers - the Yellow, the Yangtze and the Mekong - flow. The nature reserve, formed in 2000, was an effort to address the drying up of the Yellow River, where decades of overuse and pollution had caused a national alarm when it failed to reach the sea for several months in the late 90s.

There are many causes of desertification on the plateau, driven both by natural and physical processes and human mismanagement. Geology and climate change as well as human activities all play a role in exacerbating desertification. The semi-arid and fragile nature of this land is unable to sustain high densities of human and wildlife population. The vulnerability of the plateau to desertification from wind erosion, or aeolian desertification, originates from its cold and dry climate, a result of high altitude, since this climate greatly reduces vegetation growth and when vegetation is damaged or removed, recovery is slow or unlikely.

Rising temperatures accelerate the melting of permafrost, causing plants to lose their structural support, which in turn exposes the once frozen top soil to the winds and burrowing rodents such as pikes. The number of yaks and sheep have also increased rapidly since the 1970s, which in turn has placed increased ecological pressure on the grasslands through overgrazing. This combination of factors makes this region particularly susceptible to desertification. A 2015 a Chinese Academy of Science (CAS) study stated that over the last three decades an extra 2,745 square kilometres of land have been claimed by desertification in the headwaters of the Yellow River.

In 2012 Yang Yong noticed a new desert forming in Madoi county in Qinghai province on satellite images. Since he first spotted this phenomenon, the scattered patches of degraded land have connected up to form larger deserts. Madoi county is now the most severely impacted of the many affected areas in the region with 35% of its total land of 25,000 square kms classified as decertified.

This work is supported by The Pulitzer Center of Crisis Reporting
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