Melting glacier can lead to less water supply
CHINESE scientists have warned that the melting glaciers in the Qinghai-Tibet Plateau, known as the world’s Third Pole, will cause a reduced water supply in coming decades, affecting billions of people downstream.
The plateau, with tens of thousands of glaciers, is the headwaters of Asia’s 10 largest rivers, including the Yangtze, Yellow, Indus, Yarlung Zangbo and Syr Darya rivers, which provide water for 3 billion people across Asia.
By 2060 to 2070, rising temperatures due to climate change will lead to ever-stronger glacier retreat on the plateau, and rivers fed by the seasonal melting will provide less freshwater, said Yao Tandong, an award-winning glaciologist and director of the Institute of Tibetan Plateau Research with the Chinese Academy of Sciences.
A team of scientists led by Yao completed a research mission to the plateau in September. They found that from 1960 to 2012 temperature hikes in the polar region reached a staggering 0.3 to 0.4 degrees Celsius per decade, over two times that of the global average, and the glacier lost 15 percent of its mass.
“If temperatures increase 2 degrees Celsius globally as indicated by the Paris Conference on Climate Change, this region could see a hike as high as 4 degrees Celsius,” said Yao.
Though the glacier melting on the hotter plateau so far has not caused less river flow but created more water, it has resulted in ice avalanches, floods and other risks to the region.
In 2016, two glaciers collapsed and ravaged meadows, causing a lake and killing nine herders and hundreds of livestock at Aru Village in Ngari Prefecture of the Tibet Autonomous Region. Another glacier collapsed in October at the Yarlung Zangbo River in Tibet, blocking the river and forming a barrier lake. The backwater destroyed a bridge above the river.
Without actions to mitigate global warming, the rise in temperatures will aggravate evaporation and accelerate glacier retreat, causing small glaciers that cover less than 2sq km to disappear, large glaciers to shrink and main rivers to lose water, said Yao.