Chinese experts link deadly Tibet-Nepal flood to climate change

The massive flash flood that struck the Tibet-Nepal border on August 26 has put China’s numerous hydropower projects in the region, including the mega dam being built on the Brahmaputra River, under renewed scrutiny, with Chinese climate experts saying global warming and accelerating glacier retreat may have contributed to the gigantic mudslide.

Chinese experts have linked the disaster to a combination of factors, including rising temperatures, accelerated glacier melt and retreat, local geological and geomorphological conditions and broader climatic changes.

The August 26 disaster was triggered by an ice-rock avalanche near the Nepal-Tibet border, sending a massive surge of water and debris downstream through the Bhotekoshi River. The resulting floods devastated settlements in northern and central Nepal, killing more than 1,350 people, while around 5,000 remain missing.

On the Chinese side, 43 people have been killed and 519 remain missing, according to authorities. The missing include 261 foreigners, of whom 49 are from India.

Rising temperatures and extreme weather

Sun Xiaoguang, head of the Meteorological Observatory of the Tibet Autonomous Region, said monitoring had shown changes in rainfall patterns and rising temperatures in Tibet.

“According to our monitoring, we can see the short-time rain days, or the imbalance of the rain pattern and the rising of the temperature in Tibet,” Sun told PTI while travelling to the flash flood-hit area near the Tibet-Nepal border on Sunday.

He said Tibet could be affected by the wider climate change crisis and warned that China could see more extreme weather events as a result of climate change.

The disaster has drawn attention to the increasing volatility of the fragile high-altitude environment of the Qinghai-Tibet Plateau, often described as the “roof of the world”. Around 10 major transboundary rivers originate in the region, including the Brahmaputra, which flows from Tibet into India’s Arunachal Pradesh before entering Bangladesh.

The force of the August 26 mudslide, which carried huge boulders, ice and massive quantities of mud, destroyed the sprawling Chinese immigration centre at Gyirong near the border.

A group of foreign correspondents taken to the area by China’s Foreign Ministry on Sunday found virtually no trace of the building, with only a few metal rods protruding from the debris. Most of the dead and missing foreigners were in and around the immigration centre when the disaster struck.

Glaciers and glacial lakes under scrutiny

Chinese researchers say climate change is becoming an increasingly important factor behind the growing frequency and severity of disasters in high-altitude border regions.

Chinese officials said Tibet has around 33,000 glaciers, of which 187 have been categorised as high-risk and require round-the-clock satellite monitoring to detect possible collapses.

Nie Yong, a researcher at the Institute of Mountain Hazards and Environment of China, said the Qinghai-Tibet Plateau now has more than 14,000 glacial lakes covering a combined area of more than 1,100 square kilometres.

Many of these lakes are continuing to expand, he said, with the area covered by glacial lakes increasing by around 1 per cent a year. Their expansion, Nie told Chinese daily The Paper, was adding to the accumulation of geological disaster risks across high-altitude areas.

Kang Shichang, director and researcher at the Institute of Mountain Hazards and Environment under the Chinese Academy of Sciences in Chengdu, said glaciers across the Qinghai-Tibet Plateau had shrunk by about 24 per cent in area over the past six decades.

The decline has been considerably greater in the southern part of the plateau, particularly in the Gangdise Mountains, Nyenchen Tanglha Mountains and the Himalayas, where glacier area has fallen by about 40 per cent over the same period, Kang told The Paper.

He attributed the dramatic retreat primarily to global warming.

The loss of glacier ice has also contributed to a substantial increase in the number and size of glacial lakes across the plateau, raising concerns over glacial lake outburst floods, landslides and other cascading disasters.

How climate change can amplify the risk

According to specialists cited by The Paper, the chain of events behind the Gyirong Port mudslide is closely linked to the changing climate.

Higher temperatures can accelerate glacier melting. As glaciers retreat, they can leave behind unstable mountainsides, loose rock and sediment and expanding glacial lakes. Heavy precipitation or sudden structural failure can then trigger cascading hazards, including ice-rock avalanches that rapidly transform into enormous mudflows.

The disappearance of glacier ice can therefore leave behind increasingly unstable terrain and expanding bodies of water, creating new hazard zones in remote Himalayan valleys.

The August 26 disaster has consequently added a new dimension to the risks facing the region. Concerns over Tibet’s hydropower infrastructure had previously focused largely on earthquakes, given the plateau’s location along the collision zone of the Indian and Eurasian tectonic plates.

Brahmaputra mega dam faces renewed scrutiny

The disaster has also revived questions over China’s expanding hydropower infrastructure in Tibet, including its massive project on the Brahmaputra upstream of India.

China began construction of the dam in July last year at a gorge in the Himalayan reaches where the Brahmaputra makes a dramatic U-turn before flowing into Arunachal Pradesh and eventually Bangladesh.

The project has been described as the world’s largest construction project, with an estimated cost of USD 167.8 billion. It is expected to generate more than 300 billion kWh of electricity annually — enough to meet the annual electricity needs of more than 300 million people.

China has faced criticism and concern over the potential environmental and downstream implications of its hydropower projects in Tibet. The August 26 disaster has now brought climate-related risks, glacier retreat and the increasing instability of the Himalayan landscape into sharper focus.

Chinese researchers say the event is a warning of how rapidly warming temperatures are reshaping the Qinghai-Tibet Plateau and Himalayan region.

The combination of shrinking glaciers, expanding glacial lakes, extreme precipitation and unstable geological conditions could create increasingly complex risks for communities and infrastructure across the region.

The scale of the August 26 disaster, experts say, underlines the need to account not only for traditional geological hazards such as earthquakes and landslides, but also for the rapidly changing climatic and glacial conditions of the Himalayan highlands.