A recent study has revealed that 110 glaciers have disappeared in the eastern Himalayas of Arunachal Pradesh during a period of 32 years (1988-2020). This indicates rapid melting of glaciers, which can have serious impacts on the water system and climate of the region.
Key findings of the study
- Research and technical application: The study was conducted by researchers from Nagaland University and Cotton University, using remote sensing and GIS technology to detect glacier boundaries.
- Reduction in number of glaciers: The number of glaciers in Arunachal Pradesh declined from 756 to 646 during the study period.
- Reduction in glacier cover: The total glacier area declined from 23 sq km to 309.85 sq km, indicating a reduction of more than 47%.
- Location and position of glaciers: Most glaciers are located at an altitude of 4,500–4,800 m, face north and lie on slopes of 15°–35°.
- Consequences of glacier loss: This rapid glacier loss has exposed bedrock and created glacier lakes, increasing the risk of Glacial Lake Outburst Floods (GLOFs).
Glacier retreat
- Glacier retreat is the process in which glaciers decrease in size as their ice melts faster than the amount of new ice being added. It is a major indicator of global climate change and is occurring at an alarming rate, especially in high altitude regions such as the Himalayas.
Causes of glacier retreat
- Climate change: Increased global temperatures have caused ice melting to exceed the accumulation of ice.
- Changes in Precipitation Patterns: Abnormal snowfall and reduced winter rainfall slows glacier growth.
- Black Carbon Deposition: Pollutants from human activities accumulate on glaciers, which absorb more heat and accelerate the melting process.
- Geological Factors: Geographic factors such as slope, elevation, and rock types affect how glaciers respond to warming.
Effects of Glacier Retreat
- Freshwater Crisis: Retreating glaciers will severely impact water availability and distribution, adversely affecting agriculture and drinking water supplies.
- Increased GLOF Risk: The formation of glacial lakes increases the risk of natural floods. For example, the 2023 Sikkim disaster killed at least 55 people and destroyed a 1,200 MW hydropower project.
- Ecosystem Disruptions: Changes in temperature and rainfall patterns can destabilize ecosystems, negatively impacting biodiversity.