High up in the Himalayas in Nepal is a glacial lake that has been growing in length by 60 metres a year, threatening to burst its banks as rising temperatures in the region cause the glacier that feeds it to melt more quickly.
“The Nepalese government has exhausted funds to drain the Tsho Rolpa [Nepal’s biggest glacial lake] which poses an immediate threat to at least 10,000 people,” said Samjwal Bajracharya, the lead author of a new report on the Status of Glaciers in the Hindu Kush Himalayan (HKH) region, also known as the Third Pole.
Besides the imminent threat to lives, if the lake bursts its banks, it could lead to water shortages affecting hundreds of thousands who live in the Rolwaling Valley, about 110 km northeast of the Nepalese capital, Kathmandu.
The phenomenon is known glacial lake outburst floods (GLOFs), and the Intergovernmental Panel on Climate Change (IPCC) has warned of more GLOFs in the HKH region as it becomes warmer.
The report is one of three studies produced by the International Centre for Integrated Mountain Development (ICIMOD), a Kathmandu-based organization funded by eight countries that researches climate change and mountain ecosystems.
The studies compile some of the most recent research on climate change, and snow and glacier melt in the HKH region, which has the largest concentration of snow and glaciers outside of the polar regions.
However, researchers have only been able to assess 10 of the 54,000 glaciers in the region. Information on the state and behaviour of the region’s glaciers is critical because they feed 10 rivers that provide water to 20 percent of the world's population.
Changes in glacier ice or snow-melt affect the glacier’s storage capacity, and the flow of water downstream. The 10 major river systems stretch across eight Asian countries - Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal and Pakistan.
The white spot
The reports, which contain peer-reviewed studies, are a response to the need for robust evidence from the region, as highlighted by the IPCC in its last assessment, said David Molden, director-general of ICIMOD at a side event at the UN climate change conference. "The IPCC called it the white spot," pointed out Molden, because of a lack of robust scientific evidence from the region.
The IPCC has come under fire for citing “grey literature” - a report not peer-reviewed - in a projection of glacier melt in the Himalayas.
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The new reports thus have added significance. Molden said he hoped to get the studies published in a peer-reviewed journal in time for the IPCC’s next assessment, due to be released in 2013/14.
Accurate historical data is the biggest hurdle facing researchers who work on the impact of climate change on the region. Molden pointed out that weather data is hard to record in the higher reaches of this mountainous area, home to some of the world’s highest peaks.
The ICIMOD has been using data recorded by satellites, but “unfortunately we have data from satellites dating back to only the 1970s,” he noted. "We cannot therefore attribute the trends we are recording - glacial melt, a rise in temperature - directly to climate change - we would like to see our studies as a baseline for future research."
Bajracharya, a remote sensing specialist, said he has been poring over images and statistics obtained via satellites and found that within a span of 40 years, glaciers in the stretch of Himalayas in Nepal have reduced in size by 21 percent, while those in Bhutan were down by 22 percent.
“The message to the conference is to keep our global temperature increase below two degrees Celsius,” said Bajracharya. “We are already seeing the evidence of higher temperatures.”
A two-degree Celsius increase by the turn of the century would have a catastrophic effect: water stress in arid and semi-arid countries, more floods in low-lying coastal areas, coastal erosion in small island states, and the elimination of up to 30 percent of animal and plant species.
Some of the studies in the reports show that land use in parts of the region - which is home to 210 million people and affects 1.3 billion people indirectly - is changing, with tree lines and species shifting to higher altitudes. In some areas, the species in higher altitudes have nowhere else to go.
Access all the studies here