Nepal-China floods linked to global warming, say researchers

Chinese researchers say the glacier collapse that led to deadly floods in the Nepal-China border area was influenced by global warming. 

Nepal’s Rasuwa district and China’s Gyirong port in the Tibet Autonomous Region were badly damaged on 26 August. More than 1,270 people have been confirmed dead in Nepal and 4,700 remain missing, reported Al-Jazeera. At least 21 people were killed and 541 remained missing on the Chinese side as of 2 September, Xinhua reported. 

“The disaster was caused by the destabilisation of glaciers due to the long-term effects of global warming,” stated Su Pengcheng, a researcher at the Institute of Mountain Hazards and Environment, at the Chinese Academy of Sciences.  

He said a glacier on the northern face of Mount Langtang Lirung in Nepal ruptured at about 5,200 metres altitude, triggering an ice-rock avalanche. This travelled about 22 kilometres downstream through a valley before reaching Gyirong port at around 1,800 metres above sea level. 

The avalanche took only about 6 to 7 minutes to reach the border, Su said. 

Factors contributing to the destabilisation included warmer spring and summer temperatures, increased meltwater and thawing high-altitude permafrost, reported Xinhua, citing a recent joint research team led by the Institute of Tibetan Plateau Research at the Chinese Academy of Sciences.

The researchers also noted a “gradual expansion” effect – as the debris flowed downstream they incorporated material from the valley and its banks.

The findings come amid growing concerns over climate change and the increasing instability of high-altitude environments. Experts cited by People’s Daily said ice avalanches are expected to become more frequent as global warming continues. 

Ma Lijuan, a senior engineer at the National Climate Center, said the sudden nature of ice avalanches and the limited number of monitoring stations at high altitudes mean existing systems cannot reliably identify warning signs. 

Ma called for an Earth system observation network – meaning a group of instruments based on land, in the air and in space – to monitor the region’s high-risk glaciers and glacial lake areas. She suggested further research be done into the mechanisms behind major glacial hazards. A comprehensive early-warning indicator system is needed to assess and forecast future risks, she added. 

Read Dialogue Earth’s recent Q&A article on the floods.