Latest study shows Bhutan has lost 22% of its glaciers in last decade

Three reports published by International Centre for Integrated Mountain Development (ICIMOD) on December 4 coinciding with the Mountain Day in Durban, South Africa, provide the latest information on the status of climate change in the Hindu Kush Himalayan (HKH) region. It is the first comprehensive account of glacier cover and pattern of snowfall in the region.

The report titled ‘The Status of Glaciers in the HKH Region’ says the glaciers appear to be shrinking in both the central and eastern Himalayas. The glaciers in the Himalayas have shrunk by as much as a fifth in the last 30 years.

Country-specific studies have found that depletion of glacial area over the past 30 years was 22 percent in Bhutan and 21 percent in Nepal. The clean glaciers of the Tibetan plateau are retreating at a faster rate than those of the rugged central Himalayas, which have higher debris cover.

The HKH region, which is home to 30 percent of the world’s glaciers, has more than 54,000 glaciers covering an area of 60,000 sq km. This number has been known for the first time through remote sensing mechanism.

“This research provides a baseline to measure the potential impact of climate change in the region and develop options for mitigating the impact of dynamic changes the region is expecting in the coming years,” said Basanta Shrestha from ICIMOD.

Increases in glacial melting are projected to limit the natural water storage provided by snow and ice, and it will increase the risk of glacial lake outburst floods. Mass losses from glaciers and accelerating reductions in snow cover are expected to ultimately reduce water supplies and hydropower potential, according to the report.

The scientists have also predicted some changes in the seasonality of flows in river basins supplied by melt water from snow and ice. Droughts will most likely affect greater areas, and there will be need for greater reliance on irrigation even as water sources become more restricted. The risk of flooding will also increase with this impact of climate change.

The HKH region spreads over 4.2 million sq km in the eight countries of Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal, and Pakistan. The water from melting of snow and ice feeds 10 large river systems of Amu Darya, Brahmaputra, Ganges, Indus, Irrawaddy, Mekong, Salween, Tarim, Yangtze, and Yellow River. The river basins cover an area of about 9 million sq km, of which 2.8 million sq km lie within the HKH region.

The other publication titled ‘Snow-Cover Mapping and Monitoring in the HKH’ analyses the snow cover data documenting the first complete status report of snow cover in the region.

Using a decade’s data on snow cover, the authors saw an indication of an overall decrease in snow cover in the central HKH region and a slight increase in the western and eastern parts of the region. Snow cover below 5,500 metres above sea level was seasonal and above 6,000 metres permanent, with the snow line fluctuating between 5,500 and 6,000 metres above sea level. The snow cover area between these levels showed a slight decrease.

The HKH region is one of the world’s hotspots for global warming. The rise in temperature has been greater at higher altitudes and more pronounced during the cooler months than in the warmer months.

Warming across the region was seen greater than the global average of 0.74°C over the past 100 years. However, this change is not evenly distributed, and it is more pronounced in higher altitude areas. In Lhasa, for example, temperatures had increased by 1.35°C between 1950 and 1980.

At the mountain day event in Durban, Agriculture Minister Pema Gyamtsho (PhD) said the HKH region is one of the most ecologically sensitive and fragile areas in the world. The effects of climate change will likely become more evident first in the region than anywhere else since the ecosystem supports the livelihood of more people than any other ecosystem in the world.

He reiterated that meeting the challenge will require increased regional cooperation between governments and other actors. “This research, which involved eight countries in the HKH region, represents the kind of cooperation needed to meet the climate challenge,” he said.

The compilation of information on the region was considered the first vital step to launch a renewed fight against climate change. “From here, greater focus needs to be put on providing people and governments with options for climate-resilient development,” said David Molden, the director general of ICIMOD.

Findings from the reports highlight the region’s extreme vulnerability to climate change, as rising temperatures disturb the balance of snow, ice and water, threatening millions of mountain people and 1.3 billion people living downstream in Asia’s major river basins.

The region offers livelihood to 210 million people. And being rich in biodiversity, it is home to some 25,000 plant and animal species, and contains a larger diversity of forest types than the Amazon. Yet, poverty is rife in the region.

By Sonam Pelden

One Response to “Latest study shows Bhutan has lost 22% of its glaciers in last decade”

1. Himalayan Glaciers Receding says:

   January 9, 2012 at 9:22 pm

   [...] to be Chicken Littles yelling about the sky falling, but when a bunch of scientists announce that Himalayan glaciers have shrunk as much as 20 percent in the last 30 years, we take [...]

   Reply