Climate change impact: Himalayan low altitude glaciers melting fast

A new study has revealed that the Himalayan glaciers at low altitudes are melting at a faster rate than the glaciers at higher altitudes, thanks to a rise in temperatures. The degradation of glaciers has put the region under the risk of floods and also pause water scarcity in the long run. 

It is for the first time, a study of 146 glaciers spread over 660 sq km in Chandra Basin located in the western Himalayas is being conducted to estimate the volume of loss caused by climate change. The study conducted by Anil V Kulkarni of the Indian Institute of Sciences, Bangalore, has been published in the international journal Annals of Glaciology.

The glaciers in the Himalayas help sustain the lives of millions of people across India as they are a huge reservoirs of water with several rivers —  Ganga, Brahmaputra and Indus — originating from the glaciers in the Himalayas. 

Kulkarni, who previously headed the glacier monitoring unit of the India Space Research Organisation (ISRO), said: "For the first time, not only in India but globally, we have an estimate of how much volume and mass of glaciers have been lost over a period of time in Chandra basin. Now we can have similar estimates for other glaciers in the Himalayan region."

From 1984 to 2012, the Chandra Basin has lost 11.1 giga-tonnes of water. It is one-fifth of the total estimated volume of water stored in the glaciers in the region. However, the study found that the loss of volume in smaller and low altitude glaciers was about 67 percent during the same period.

"I would like to caution that there is no danger of the glaciers vanishing in near future," Kulkarni was quoted by Hindustan Times as saying, adding that the "small ones" may not be there in the long run. He further added that the study helps in the better understanding of fresh water stored in the Himalayan glaciers. It would also be important for water resource management to implement necessary mitigation measures. 

The study covered 146 glaciers in the basin located in the Lahaul-Spiti Valley of Himachal Pradesh, a region which has seen a rise in temperatures up to two degrees in the last century. The mass balance of the glaciers in the Himalayas was estimated on the basis of satellite data by a team of researchers from various scientific institutes across India.

According to ISRO, the Himalayan region consists of 34,919 glaciers spread over 75,779 sq km of glaciated areas in the Indus, Ganga and Brahmaputra river basins. There were no changes seen in 1,752 glaciers but 18 did show advancement. The remaining glaciers are retreating due to rise in emissions and debris.

In a separate study, Kulkarni had stated that the glaciers in the HImalayan region have retreated by around 13 percent over the last 40 years. The loss in water content rose from nine giga-tonnes per year in 1975-1985 to 20 giga-tonnes per year in 2010-2015.