"The largest global store of frozen water after the polar regions” serves water to nearly two billion people, yet changes in climate mean it too has been affected, as are the countries that are dependent on it.
The Tibetan Plateau is being affected adversely from “a water imbalance so extreme that it could lead to increase in international conflicts.”
“Climate change is disrupting weather patterns, leading to extreme weather events, unpredictable water availability, exacerbating water scarcity and contaminating water supplies. Such impacts can drastically affect the quantity and quality of water that children need to survive,” says UNICEF.
Writing in the journal Nature Reviews Earth and Environment, they say “The Hindu Kush–Karakoram–Himalayan system, named the Third Pole because it is the largest global store of frozen water after the polar regions, provides a reliable water supply to almost 2 billion people. Marked atmospheric warming has changed the balance of this so-called Asian water tower and altered water resources in downstream countries.”
The Asian water tower (AWT) functions as a complex water distribution system for several countries, including parts of China, India, Nepal, Pakistan, Afghanistan, Tajikistan and Kyrgyzstan.
However, the Tibetan Plateau cannot sustainably support the continued growth of the developing nations that depend on it because of the rapid melting of snow and upstream glaciers.
“Populations are growing so rapidly, and so is the water demand,” said Lonnie Thompson, distinguished university professor of earth sciences at The Ohio State University and senior research scientist at the Byrd Polar Research Center.
“These problems can lead to increased risks of international and even intranational disputes, and in the past, they have.”
Thompson has studied climate change for almost five decades and is highly familiar with the delicate nature of the region’s hydrological situation. In 1984, he was one of the members of the first Western team that was sent to explore the glaciers in China and Tibet.
Since then, he and a team of international colleagues have been poring over ice core-derived climate records and the area’s rapidly receding ice along with the impact it has had on the local settlements that rely on the Asian water tower for their freshwater needs.
Thompson is one of the co-authors of the paper. The authors evaluated temperature change data between 1980 and 2018 to record regional fluctuations. Their findings laid bare the fact that “warming of the Asian Water Tower (AWT) was 0.42 °C per decade, twice the global average rate.”
“This has huge implications for the glaciers, particularly those in the Himalayas,” Thompson said. “Overall, we’re losing water off the plateau, about 50% more water than we’re gaining.”
The study documents the the water loss as: “From 2000 to 2018, total glacier mass in the AWT decreased by about 340 [Gigatonnes] whereas total water mass in lakes increased by 166 Gt.”
The authors also wrote: “Global warming is expected to amplify this imbalance, alleviating water scarcity in the Yellow and Yangtze River basins and increasing scarcity in the Indus and Amu Darya River basins.”
The study’s authors, noting that many vulnerable societies live by these downstream basins, warn that the worsening disparity could increase conflicts or exacerbate already tense situations that share these river basins, such as the long-term irrigation and water struggles between India and Pakistan.
“The way that regional climate varies, there are winners and losers,” Thompson said. “But we have to learn to work together in order to ensure adequate and equitable water supplies throughout this region.” As local temperatures continue to rise and water resources become depleted, more people will end up facing ever diminishing water supplies, he said.
On the other hand, overall increases in precipitation by themselves will not be able to satisfy the increasing water demands of downstream regions and countries.
In order to counter this, the authors suggest using more comprehensive water monitoring systems in data-scarce areas, explaining that better atmospheric and hydrologic models are needed to help foresee what’s happening to the area’s water supply.
The authors say “Comprehensive monitoring systems, advanced modelling capacity and sustainable water management are needed to develop adaptation policies for the AWT through collaboration between upstream and downstream regions and countries.”
The study explains that people around the world must be aware that changes in one part of the world affect other parts of the world, with long-lasting effects, as is the case with the butterfly effect.
“Climate change is a global process,” Thompson said. “It doesn't matter what country or what part of the world you come from. Sooner or later, you’ll have a similar problem.”