Kathmandu: Glaciers in the Everest region of the Himalayas could shrink at least 70 per cent or even disappear entirely by the end of the century if greenhouse-gas emissions continue to rise, scientists warned today.
A team of researchers in Nepal, France and the Netherlands have found Everest glaciers could be very sensitive to future warming, and that sustained ice loss through the 21st century is likely.
“The signal of future glacier change in the region is clear: continued and possibly accelerated mass loss from glaciers is likely given the projected increase in temperatures,” said Joseph Shea, a glacier hydrologist at the International Centre for Integrated Mountain Development (ICIMOD), Kathmandu, and leader of the study.
The glacier model used by Shea and his team shows that glacier volume could be reduced between 70 per cent and 99 per cent by 2100. The results depend on how much greenhouse-gas emissions continue to rise, and on how this will affect temperature, snowfall and rainfall in the area, researchers said.
“Our results indicate that these glaciers may be highly sensitive to changes in temperature, and that increases in precipitation are not enough to offset the increased melt,” Shea wrote in the study published in The Cryosphere journal.
Increased temperatures will not only increase the rates of snow and ice melt, but can also result in a change of
precipitation from snow to rain at critical elevations, where glaciers are concentrated.
Together, these act to reduce glacier growth and increase the area exposed to melt, researchers said. Glaciers in High Mountain Asia, a region that includes the Himalayas, contain the largest volume of ice outside the polar regions.
The team studied glaciers in the Dudh Kosi basin in the Nepal Himalaya, which is home to some of the world’s highest mountain peaks, including the 8,848 metre high Mt Everest, and to over 400 square kilometres of glacier area.
“Apart from the significance of the region, glaciers in the Dudh Kosi basin contribute melt-water to the Kosi River, and glacier changes will affect river flows downstream,” said Shea.