Report: Asia’s top 10 river systems at risk from climate change

Asia’s top 10 river systems, which play a vital role in the economies and energy security of 16 countries, face major disruptions due to climate change, a new report warns, calling for urgent action to safeguard regional water flow .

The basins of the 10 rivers originating from the Hindu Kush-Himalayan water towers are inhabited by 1.9 billion people and contribute US$4.3 trillion to annual gross domestic product, according to the “No River, No Power” report. ” by China Water Risk (CWR), a Hong Kong-based non-profit think tank.

The risk of climate change means that as many as one in two Asians could be affected by increasing water scarcity due to accelerated melting of glaciers, reduced snowfall, changing monsoon patterns and overexploitation of water resources. underground, according to the report released Wednesday.

Asia gets most of its water from the Himalayas, the Hindu Kush, the Karakorum Mountains, and the Tibetan Plateau. Collectively, they are often called the “Third Pole” or “Water Towers of Asia”, making up 10 major river basins.

These include the Amu Darya, Brahmaputra, Ganges, Indus, Ayeyarwady, Mekong, Salween, Tarim, Yangtze, and Yellow rivers. They flow through 16 countries, including China and most of Central, South and Southeast Asia before reaching the seas or ending up in a desert.

Known as the continent’s cradles of civilization, they are also responsible for nearly three-quarters of the world’s rice production.

The report says most countries are developing, which means more people will flock to more than 280 big cities along rivers, adding pressure to already stressed systems.

According to the report’s projection, all rivers face increasing and exacerbating water risks due to climate change, and four of the 10 rivers will experience an overall decline in river flows by 2050 if the land warms at the threshold. from 1.5 to 2 degrees Celsius set by the climate of Paris. agreement.

Such impacts will affect power generation from the 10 river systems, currently responsible for 865 gigawatts (GW), or 46% of the total electrical capacity in the 16 countries, according to the report. It is more than the combined capacity of Brazil, Canada, Germany, Japan and Russia.

More than 94% of this installed capacity (865 GW) needs water to generate electricity, with coal and hydropower making up the majority, while more than a third is already in river basin areas facing water stress of “High” to “Extremely High”. or are in arid regions.

“Uncertain future flows of the 10 rivers and extreme weather mean we must select mountain-to-ocean hydronomic roadmaps and energy systems that are resilient to climate change,” said Debra Tan, director of the think tank and lead author of the paper. report.

“Therefore, national energy and water security plans must fit together. The need to do all of this is ever more urgent, as doing so will help us manage the growing and exacerbating risks of water, as well as meet the growing demand for water.”

Laos, Cambodia and Myanmar highest risk countries

According to the report, landlocked Laos is the most exposed among the risk groups, along with Myanmar and Cambodia in the overall high-risk group, while China is considered a medium-high risk and Vietnam a low risk. .

In Laos, the Mekong accounts for two-thirds of its surface water and is home to more than 90% of its population and gross domestic product, according to the report, with nearly 100% of Laos’ national installed capacity in the Mekong.

Similarly, Cambodia receives 26% of its surface water from the Mekong, home to 79% of its population and 85% of its GDP. About two-thirds of Cambodia’s national installed capacity as hydropower is located in the Mekong River basin.

In Myanmar, Ayeyarwady, Salween and Mekong provide 35% of the country’s surface water and are home to 58% of its population and contribute 46% of its GDP. Almost two thirds of its installed power capacity is in Ayeyarwady and one third in Salween.

The report also noted that an increase in “just in case” coal-fired power additions in China after severe droughts along the Yangtze in 2022 is just one of many cascading effects of climate change impacts.

Of the 10 rivers, only the Amu Darya does not flow through China. The other nine rivers provide half of China’s surface water, support about 44% of its population, and contribute about 30% of its GDP.

China has about half of its national power scattered among seven rivers, with the lion’s share in the Yangtze and Yellow river basins.

Asia-Pacific is home to 80% of global coal generation, while power sector emissions in the region account for 62% of the global total.

Asia’s heavy reliance on an expanding coal-fired power fleet is only accelerating climate change and exacerbating water scarcity, according to the report, which warns that such power generation requires water to cool and drive steam turbines. , making energy security even more vulnerable during a water crisis.

The transboundary nature of river systems also increases the risk, he said, giving an example of the Mekong flowing through five countries.

“This means that transboundary management of eight of the 10 rivers must not only focus on water sharing, but also on energy policy and development,” said CT Low, CWR’s geospatial risk lead and co-author of the report.

Edited by Mike Firn.