The Tibetan Plateau will experience significant water loss this century due to global warming, according to a study published Monday, which warns of serious supply shortages in a climate change “hotspot”.
The reservoirs of the Tibetan Plateau, which cover much of southern China and northern India, are fed by the monsoon and currently provide most of the water needs of nearly two billion people.
However, the plateau’s complex terrain has made it difficult for scientists to predict how warming temperatures and changing weather patterns associated with climate change will affect the region’s water supplies.
Researchers in China and the United States used satellite-based measurements to determine the net change in water and ice mass over the past two decades.
They added direct measurements of glaciers, lakes and subsurface water levels to estimate changes in water mass, and then used a machine learning technique to predict storage changes under scenarios such as higher air temperature and lower cloud cover.
They found that the Tibetan Plateau has lost just over 10 billion tons of water annually since 2002 due to an increasingly warm and humid climate.
Writing in the journal Nature Climate Change, the team projected changes in water storage across the plateau under an intermediate emissions scenario in which carbon pollution remains around current levels before gradually decreasing after 2050.
They found that two river basins were particularly vulnerable to water loss.
In the Amudarya, Central Asia’s largest river, the water loss could equal 119 percent of current needs.
The study showed that communities that depend on the Indus Basin for water supplies could see a loss of 79 percent of current needs.
The authors recommended governments explore alternative water supply options, including increasing groundwater abstraction, to make up for expected shortages.
Michael Mann, director of the Penn Center for Science, Sustainability and the Media, said “significant reductions in carbon emissions over the next decade” would limit global warming and the “predicted collapse of the Tibetan Plateau’s water towers.”
“But even in the best-case scenario, further losses are likely to be inevitable, which will require significant adjustment to dwindling water resources in this vulnerable, densely populated region of the world.” Exactly what that would look like is hard to say — we’re in uncharted waters,” Mann, a co-author of the study, told AFP.
“Suffice it to say that a certain amount of suffering is involved.”
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