Global warming accelerates glacier melting, raising Himalayan disaster risks, experts say

Experts said global warming was a major factor behind the catastrophic mudslide on August 26, caused by a massive glacier collapse in Nepal.

Driven by global warming, glaciers around the world, including those on China's Qinghai-Xizang Plateau, are shrinking at an accelerating pace each year, increasing the risk of such geological hazards.

Glaciers shrinking rapidly

Experts said China's long-term glacier inventory work has provided important support for the glacier monitoring and early-warning systems in the region.

China has completed three nationwide glacier inventories over the past 60 years. Data show that glacier coverage on the Qinghai-Xizang Plateau has declined significantly, from about 61,000 square kilometers recorded in the first inventory to 44,000 square kilometers in the second, and the latest inventory shows the glacier area has fallen to about 39,000 square kilometers.

Kang Shichang, director general of the Institute of Mountain Hazards and Environment (IMHE) under the Chinese Academy of Sciences, said glaciers on the plateau have retreated rapidly over the past 60 years.

Glacier area on the Qinghai-Xizang Plateau has shrunk by about 24% over the past six decades, nearly a quarter, Kang said, adding that the most severe retreat has occurred in the southern part of the plateau, including the Gangdise Mountains, Nyenchen Tanglha Mountains and the Himalayas, where glacier area has decreased by about 40%.

Kang attributed this mainly to global warming, noting that glaciers worldwide are declining.

Expanding glacial lakes

One direct consequence of glacier retreat is the significant expansion of glacial lakes. Monitoring data show that more than 14,000 glacial lakes now cover more than 1,100 square kilometers across the Qinghai-Xizang Plateau.

Glacial lakes have generally expanded rapidly over the past decades, especially in the Himalayan region along China's southern border, said Nie Yong, a researcher at the IMHE. "Glacial lakes in this area are growing by about 1% each year."

Chain disasters

Experts said glacier-related disasters are often interconnected rather than isolated events. Glacial lake outbursts, ice avalanches and ice-rock avalanches can trigger a chain of cascading hazards.

In the Himalayas, more than 100 glacial lakes are currently considered high risk.

For example, after a glacier collapse in Nepal, debris blocked river channels and formed a barrier lake along the China-Nepal border. If the barrier lake breaches, it could further trigger a chain of secondary disasters, creating a chain reaction that amplifies the overall impact.

The cascading effect makes monitoring, early warning, and disaster prevention for such geological disasters challenging.

The Himalayas cross national borders, said Liu Qiao, an IMHE researcher. When an event occurs in Nepal and affects China, the two countries need to share information, conduct joint monitoring and respond together.

Improving the cross-border joint prevention and control system is a key area that needs continued strengthening to prevent and manage disasters in high-altitude border areas now and in the future, Liu said.