Studies hint at faster glacial retreat
THE HINDU KUSH HIMALAYAN REGION EXPERIENCED A TEMPERATURE RISE OF ABOUT 1.3 DEGREES CELSIUS FROM 1951 TO 2014
NEW DELHI: The Chamoli glacial breach and the disaster it has unleashed may be, in a manner of speaking, the tip of the iceberg.
Latest scientific research suggests that the retreat of glaciers in the entire Himalayan region, except some parts of the Karakoram range, has gathered pace. This, scientists say, will lead to more frequent disasters induced by glacier melt.
A report modelled on the Intergovernmental Panel on Climate Change’s assessment reports, “Assessment of Climate Change over the Indian Region”, flagged last year that the Himalayas and the Tibetan plateau recorded a warming of 0.2 degrees Celsius per decade during 1951–2014. In the higher reaches, the warming was at the rate of 0.5 degrees Celsius per decade — a much higherthan-average warming experienced over the entire country.
The Hindu Kush Himalayan (HKH) region — which covers 3,500 km across Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal and Pakistan — experienced a temperature rise of about 1.3 degree Celsius between 1951 and 2014 compared to average temperature rise of around 0.7 degrees Celsius during 1901 to 2018 over the country, the report by the Union ministry of earth sciences said. This, the report added, has led to several areas of HKH recording a steep decline in snowfall, and led to a retreat of glaciers. The Karakoram Himalayas — which are the northwestern extension of the Himalayas and cover Gilgit-baltistan, Ladakh, and parts of China — however, have experienced higher winter snowfall and therefore far less glacial retreat, the report said.
“There is now consensus that most glaciers in the Himalayas are retreating with the pace accelerating from the beginning of 21st century. As several studies have shown, warming is much higher in the upper reaches of Himalayas, with loss of glaciers, glacial lake formations have increased. These lakes can burst and there can be flash floods... Our team is likely to have some conclusions on the Chamoli disaster soon,” said Professor Anil Kulkarni, distinguished scientist at the Divecha Centre for Climate Change.
Two other reports underlined that more Chamoli-like disasters were likely. One was the IPCC special report on Oceans and Cryosphere in a Changing Climate, in September 2019, and the Hindu Kush Himalaya Assessment by International Centre for Integrated Mountain Development (Icimod), in February 2019.
The IPCC report said glacier retreat and snow cover changes have contributed to localised declines in agricultural yields in some high mountain regions, including the Hindu Kush Himalayas and the tropical Andes. Changes in frequency and intensity of extreme rain events vary according to season and region.
The Icimod report, while warning that glaciers have thinned, said the glacier volume in HKH is likely to decline by 36% in a 1.5-degree global warming scenario, and by 64% by the end of century if current emissions continue.
“Rapid retreat of glaciers result in formation of glacial lakes. Therefore, with warming there is increased risks of glacial lake outburst floods… There is an urgent need to strengthen our network in these locations thereby providing continuous monitoring of our weather and river flow conditions...,” said Mandira Shrestha, water resources and disaster specialist at Icimod, Kathmandu.