Japanese researchers say three glaciers have shrunk over the past 40 years due to climate change and two may disappear altogether. Reuters reports via The Guardian.
Three Himalayan glaciers have been shrinking over the past 40 years due to global warming and two of them, located in humid regions and on lower altitudes in central and east Nepal, may disappear in the future, researchers in Japan said on Tuesday.
Using global positioning system and simulation models, they found that the shrinkage of two of the glaciers – Yala in central and AX010 in eastern Nepal – had accelerated in the past 10 years compared with the 1970s and 1980s.
Yala’s mass shrank by 0.8 (2.6 feet) and AX010 by 0.81 metres respectively per year in the 2000s, up from 0.68 and 0.72m per year between 1970 and 1990, said Koji Fujita at the Graduate School of Environmental Studies in Nagoya University in Japan.
“For Yala and AX, these regions showed significant warming … that’s why the rate of shrinking was accelerated,” Fujita told Reuters by telephone. “Yala and AX will disappear but we are not sure when. To know when, we have to calculate using another simulation (model) and take into account the glacial flow,” Fujita said, but added that his team did not have the data to do so at the moment.
The Himalayas is an enormous mountain range consisting of about 15,000 glaciers and some of the world’s highest peaks, including the 8,848m-high Mount Everest and K2.
Apart from climate change and humidity, elevation also appears to play a critical role in the lifespan of glaciers, which are large persistent bodies of ice.
The Rikha Samba glacier in the drier region of west Nepal has also been getting smaller since the 1970s, but its rate of shrinking slowed to 0.48m per year in the past 10 years compared to 0.57m per year in the 1970s and 1980s.
This was because the 5,700m-high glacier was located on a higher altitude, which meant that losses in mass from melting could be compensated at least partly by collection of snowfall, Fujita said.
“In the case of Yala and AX, they are situated on lower elevation (altitudes), therefore shrinkage was accelerated. Glaciers that have no chance to get snow mass will eventually disappear,” Fujita said.
- Three Quarters of Himalayan Glaciers Retreating (treehugger.com)
- Himalayan glaciers show mixed response to climate change (chimalaya.org)
- A Seventy-Year History of Change in the Himalayas’ Raikot Glacier (chimalaya.org)
- More than 2000 Himalayan glaciers receding in India (chimalaya.org)