ISLANDn an April morning in Sagarmatha National Park, a World Heritage Site in the Himalayas that includes Mount Everest, Domi Sherpa looks out on rocky black slopes that stand sharply against snow-capped mountains. In the past, these dark swathes would also have been covered in snow and ice. But, Sherpa says, the region’s melting glaciers have increasingly exposed the rocks below.
The Hindu Kush Himalayas have the world’s third largest concentration of glaciers, after the Arctic and Antarctic. For this reason, they are sometimes referred to as “the third pole.“However, the region has been warming up faster than the global average. The glaciers are retreating, an erasure that has accelerated in the last few decades – and they can affect the water supply to local communities both near and far.
According to one 2017 survey published in Nature, by 2100, only 37 to 49 percent of Himalayan glacier mass will remain (compared to 2005 figures) if global temperatures rise 1.5 degrees Celsius above pre-industrial levels. Climate experts say the changes will continue to alter the hydrological cycle in the region. “Glaciers and glacial lakes in the high mountains are very sensitive indicators of ongoing climate change,” Sudeep Thakuri, a glaciologist at Tribhuvan University in Nepal, wrote in an email to Undark. The Himalayas are such an important source of water in Asia that they are sometimes referred to as the continent’swater towers.”
Locals have noticed the differences over the years. Anu Sherpa started climbing Everest in 1970 when he was 24 years old; he retired in 1994 and now runs a shop at Namche Bazaar. Over the years, Anu Sherpa has noticed changes in the area’s climate. The seasons are less predictable, he said. The rain doesn’t come when expected, he added, and “this time it should have been warm, but it’s not.” Across the region, the changes in water levels in local rivers are likely to affect agriculture, sanitation and fresh drinking water.
Even people far away will feel the effects of melting glaciers. And these changes will affect a lot of people: Rivers downstream supply water to nearly one fifth of the global population. The low-lying plains of Nepal and the coastal areas of Bangladesh, for example, would initially experience a rise in water levels, Thakuri said — a situation that would lead to more flooding. Over time, however, the situation can reverse. Because the glaciers would no longer hold as much ice and snow, he added, rivers downstream could receive less water during the dry seasons.
Zakir Hossain Chowdhury is a visual journalist based in Bangladesh covering climate change and human rights. His work has appeared in TIME, The Guardian, The Telegraph and The Wall Street Journal, among others. All photos by the author.