Scientists warned Tuesday that glaciers providing critical water to nearly two billion people are melting faster than ever due to climate change, exposing communities to unpredictable and costly disasters. The glaciers in the Hindu Kush Himalayan mountain ranges are disappearing at unprecedented rates. According to a report from the Kathmandu-based International Center for Integrated Mountain Development, they could lose 80% of their current volume this century if greenhouse gas emissions aren’t sharply reduced. The accelerated melt threatens flash floods and avalanches and reduces the availability of fresh water to downstream communities.
The ice sheets in the region are losing mass at an average rate of 6.5 kilometers per year from 2011 to 2020 – almost twice as fast as the previous decade. The ice loss is mainly due to rising temperatures fueling surface melting and increasing the speed of ice movement as warm air flows over colder glacial ice. The ice is also melting because the underlying bedrock is heating up as it is exposed.
In addition to the direct impacts of increased melt and lower snow cover on local economies, climate change also contributes to regional conflict as the melting glaciers create new lakes and floodplains, requiring governments to invest in infrastructure less resilient to extreme events. The influx of sediments and debris into rivers from the melting glaciers also drives riverbed erosion, which can trigger landslides and flash flooding that directly threaten populations in the high mountain valleys.
About 240 million people live in the high mountain regions of the Hindu Kush Himalayas, with cultures dating back thousands of years, and another 1.65 billion live downstream of 12 rivers that originate in the mountains. The report said this accelerated glacial loss would cause dangerous flooding and water shortages in both areas. It will also increase the frequency and severity of landslides and avalanches, which threaten the lives of those who rely on their homes and crops in the mountains for food, fuel, and income.
Glaciers across Asia’s highest mountain ranges have been wasting rapidly since the 1980s. While the Himalayas are generally not as warm as the more closely studied European Alps, they are melting similarly. The melting ice and shrinking snow cover will profoundly affect the nearly 2 billion people in Asia dependent on glacier-derived freshwater, including drinking, irrigation, and hydropower.
“As it gets warmer, ice will melt; that was expected,” said Hamish Pritchard, a glaciologist at the British Antarctic Survey not involved in the study. “We’re seeing now that the Himalayas are melting much faster than anyone thought possible.”
Some 200 glacier lakes across the mountains are deemed dangerous, and the region could see a spike in glacial lake outburst floods in the coming decades if global warming continues on its present trajectory. The report said the Himalayas are the source of 10 of the world’s most important river systems, including the Ganges, Indus, Yellow, Mekong, and Irrawaddy, which supply two billion people with food, energy, and clean water.
