Guwahati: A new study reveals a significant loss of glaciers in a section of the eastern Himalayas in Arunachal Pradesh.
Over a 32-year period (1988-2020), researchers documented the disappearance of 110 glaciers, representing a retreat of 309.85 sq. km, or a loss of over 47% of the total glacial cover.
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The research, conducted by scientists from Nagaland University and Cotton University, was published in the Journal of Earth System Science.
Using remote sensing and GIS technology, the team mapped glacier changes across several districts in Arunachal Pradesh, from Tawang to Lohit. They found the number of glaciers decreased from 756 to 646. The study also utilized the Randolph Glacier Inventory as a reference.
This glacial retreat, a key indicator of climate change, exposes bedrock and creates glacial lakes, increasing the risk of dangerous glacial lake outburst floods (GLOFs).
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The eastern Himalayas are particularly vulnerable, as evidenced by the devastating 2023 Sikkim GLOF that killed at least 55 people.
The researchers focused on glaciers located primarily between 4,500 and 4,800 meters above sea level, facing north and situated on slopes between 15° and 35°. The Himalayan range, often called the “Third Pole” due to its vast ice reserves, is a crucial freshwater source for over 1.3 billion people.
The study pointed out the alarming rate of glacial retreat in the Himalayas compared to the global average. Smaller glaciers, those under 5 sq. km, are shrinking the fastest.
While rainfall patterns have been erratic, no significant trend in precipitation was found, underscoring the complex and unpredictable nature of climate change in the region.
The research confirms that the eastern Himalayas are warming at a rate exceeding the global average, with temperatures increasing between 0.1° and 0.8°C per decade.
This warming trend is projected to continue, with potential temperature rises of 5-6°C and precipitation increases of 20-30% by the end of the century. The study notes that the global average temperature has increased by 1.6°C in the last century, with the northwestern Himalayas experiencing an even higher rate of warming.
Dr. Nabajit Hazarika, one of the study’s authors, said the severe consequences of glacial retreat, including impacts on freshwater availability, ecosystem health, and the increased risk of GLOFs.
He stressed the importance of understanding how climate change affects these vital frozen water reserves.