The melting of Himalayan glaciers is more severe than expected, a new study has found, in the latest warning against the region’s accelerating ice loss and its far-reaching consequences, including flood risks and threats to water security.

A total of 270 million tons of lost glaciers terminating into lakes in the greater Himalaya between 2000 and 2020 was not measured in the previous estimation, an underestimation of approximately 6.5%, according to a study published in Nature Geoscience on Monday. The study, conducted by the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences, said that the largest underestimation was 10% for the central Himalaya.

The number of proglacial lakes, which are formed by melting glaciers, increased by 47% and the amount of lake water rose by 42% in the same period, according to the study. The findings are based on measurements of volume changes in 16 major proglacial lakes between 2018 and 2021 and data collected from satellite images.

“This study shows that glacier mass loss in the greater Himalaya is even larger than previously thought,” Zhang Guoqing, one of the authors of the study, said in the study. “Moreover, subaqueous mass loss in the greater Himalaya will continue to be a major contributor to total ice mass loss throughout the 21st century because more lakes are projected to develop.”

The new findings have added to the mounting concerns over climate change rapidly melting the Himalayan glaciers. It is estimated that they will shrink by two-thirds by the end of this century if global warming continues. Known as the “Third Pole,” the region has the third largest concentration of glaciers in the world and feeds a major river system that serves a significant source of water and energy in many Asian countries, including China, India, Pakistan, and Nepal.

The thawing in the region is accelerating and happening faster than some other places, according to a 2021 study published in Scientific Reports, which said that the Himalayan glaciers were melting 10 times faster than during the Little Ice Age, around 400 to 700 years ago. The size of the glacier coverage was only 60% compared to the Little Ice Age.

The huge loss of ice in the region, which directly affects the solidity of frozen soil, could lead to increasing landslides or glacial lake outburst floods in Asian countries, according to scientists. In 2021, a major rock and ice avalanche killed 200 people in India, and the melt, coupled with extreme rainfall, contributed to the deluge that caused the massive flooding in Pakistan last year.

The melting glaciers could also pose greater risks to long-term water supply and electricity and have implications for many dams planned in downstream regions, scientists warned. As two of the largest hydropower producers in Asia, China generated around 1,300 terawatt hours of electricity from hydropower, while India produced one-tenth of that in 2021.

Editor: Bibek Bhandari.

(Header image: An aerial view of Zhanqiong Glacier on the Tibet Plateau, Aug. 25, 2015. VCG)