Swelling lakes in Tibet due to climate change could cause heavy losses for China: Study

BEIJING: Numerous lakes in Tibet dotting the picturesque Himalayan region are set to swell with billions of tonnes of water due to increased rainfall caused by climate warming and the melting of glaciers which could cause massive economic losses for China, a study by a group of international scientists has said.

By the end of the century, the surface area of some lakes in the Qinghai-Tibet Plateau could increase by more than 50 per cent with the water volume of the lakes in the plateau estimated to expand by more than 600 billion tonnes, according to the study published in the peer-reviewed journal Nature Geoscience last month.

If these predictions are correct, the researchers said it could have a massive economic impact on China, running into the billions of dollars, the Hong Kong-based South China Morning Post reported on Monday, quoting the study's findings.

“Our results suggest that by 2100, even under a low-emissions scenario, the surface area of endorheic lakes on the Tibetan Plateau will increase by over 50 per cent (around 20,000 sq km or 7,722 sq miles) and water levels will rise by around 10 metres (32 feet) relative to 2020,” the study said.

Endorheic lakes, also known as closed lakes, do not have an outlet to drain into.

The scientists from China, Wales, Saudi Arabia, the United States and France said this would correspond to a four-fold increase in water storage compared to what the area experienced over the last 50 years.

If steps are not taken to mitigate this, “more than 1,000 km of roads, approximately 500 settlements and around 10,000 sq km of ecological components such as grasslands, wetlands and croplands,” will become submerged, the study said.

Observers say that the swelling lakes and melting glaciers could also impact neighbouring countries including India as Tibet is the origin of several rivers including the mighty Brahmaputra.

The Qinghai-Tibet Plateau, known as the "Water Tower of Asia", is the highest and largest plateau in the world and is home to more than 1,000 lakes with large reserves of water in both liquid and ice form.

“[It is] one of the regions that is most vulnerable to climate change acting as an early warning signal for the wider effects of global warming,” the researchers wrote.

China has invested billions of dollars in developing rail, road, and aerial infrastructure in the remote region to consolidate its hold over the strategically important Himalayan region.

While large lakes in other parts of the world have been experiencing a decline in water storage due to rising temperatures and human activity, lakes in the plateau have been expanding in recent decades due to warmer and wetter conditions, the study said.

Increases in net precipitation have mostly driven this. While melting glaciers also contribute to this phenomenon, the researchers said the remaining glaciers have “limited storage”.

Despite the northern parts of the plateau being projected to experience the largest increase in water storage, roads in the northeast, where there is more human activity and infrastructure, will be the most vulnerable to inundation.

Looking at the researchers’ middle socioeconomic scenario, the study estimated that inundated roads could directly lead to an economic loss of 20 billion yuan to 50 billion yuan (USD 2.7 billion to USD 6.9 billion) by the end of the century.

This “is a serious threat that should be considered in future rail and road planning”, the study said.