A Himalayan warning
A new paper published in Nature (Accelerated mass loss of Himalayan glaciers since the Little Ice Age) on Monday said that glaciers are undergoing mass loss at an alarming rate. Around 14,798 glaciers have lost 40% of their Little Ice Age area (400 to 700 years ago). The 10-fold acceleration in ice loss, observed across the Himalayas, far exceeds any centennial-scale rates of change that have been recorded elsewhere in the world, the paper said.
The research paper shows the vulnerability of the Himalayan ecosystem, something several scientific studies, including the one by the Intergovernmental Panel on Climate Change, have highlighted. In the short term, this leads to lake formations due to meltwater, and these could overflow or burst, leading to flash floods. The paper’s authors have warned that the number and size of these lakes are increasing, so continued acceleration in mass loss can be expected. However, there is little consensus on how such glacial retreat will impact hydrological resources in the long run. Some studies suggest a severe water shortage due to glacier loss. The Himalayan Glaciers: Climate Change, Water Resources, and Water Security, a 2012 report by the National Research Council, suggests that at lower elevations, glacial retreat is unlikely to cause significant changes in water availability over the next several decades, but that at higher elevations, there could be altered water flow into river basins. Snow and glacier melt contribute more than 50% of run-off in the Indus river system and around 20% in the Upper Ganga basin, according to Divecha Centre for Climate Change.
The Hindu Kush Himalayas (HKH) experienced a temperature rise of about 1.3 degrees Celsius between 1951 and 2014. As a result, several areas of HKH have experienced a declining trend in snowfall and witnessed significant glacier retreat in recent decades, a report by the ministry of earth sciences has flagged. Future warming in the HKH region, which is projected to be in the range of 2.6–4.6 degrees Celsius by the end of the century, will lead to profound hydrological and agricultural impacts in the region, it has concluded. Therefore, the government should start long-term glacier-monitoring programmes to understand the likely impact on agriculture, water availability, and the possibility of disasters downstream.