Retreating Himalayan Glaciers

Syllabus: GS3/Environment; Climate Change

Context

  • A recent study has revealed that the eastern Himalayas of Arunachal Pradesh have lost 110 glaciers over a span of 32 years (1988-2020) and highlights the rapid retreat of glaciers, which has significant implications for the region’s hydrology and climate.

Key Findings of Study

  • Glacial Lakes: The study found that the glaciers, covering an area of 309.85 square kilometers, retreated at a rate of 16.94 square kilometers per year.
    • It exposed bedrock and created glacial lakes, increasing the risk of Glacial Lake Outburst Floods (GLOFs).
    • The number of glaciers in the region decreased from 756 to 646 during the study period.
  • Causes of Glacial Retreat:
    • Rise in Temperature: The eastern Himalayas have been warming at a rate surpassing the global average, with temperature increases between 0.1°C and 0.8°C per decade.
      • It is expected to continue, with potential temperature rises of 5-6°C and precipitation increases of 20-30% by the end of the century.
      • Over the past century, the region has seen an increase in temperature by approximately 1.6°C, with the eastern Himalayas warming at a rate surpassing the global average.
  • Implications: For the region’s freshwater supply, which supports over 1.3 billion people living downstream.
    • The Himalayan glaciers, often referred to as the ‘Third Pole’ due to their vast ice reserves, play a crucial role in maintaining the region’s hydrological balance and the global sea level.
    • The retreat of glaciers also affects the region’s biodiversity and agricultural practices. Additionally, the reduced glacial mass can lead to changes in river flow patterns, affecting hydropower generation and irrigation systems.
Himalayan Glaciers in the India
– These are broadly divided into three river basins, namely Indus, Ganga and Brahmaputra.The higher altitudes (temperate climates) receive heavy snowfall during winters.
Indus River
– It originates in the Tibetan plateau near Lake Mansarovar and Mount Kailash and flows westward, south of Karakoram Range and north of the Great Himalayas to Mt. Naga Parbat where it turns sharply to the south flowing through Pakistan into the Arabian Sea near Karachi after travelling for 2,880 kilometres.
Ganga River
– It originates from the Gangotri Glacier where it is known as Bhagirathi which is joined by Alaknanda at Devprayag and combined together it is called Ganga.
Brahmaputra River (Yalu Zangbu or Tsang Po)
– It rises in the glacier of the Kailash range, just south of Lake Konggyu Tsho in Tibet.
– It ranks amongst the longest rivers of the world. It traverses its first 1,625 kilometres in Tibet, 918 kilometres in India and the remaining 337 kilometres in Bangladesh before it drains into the Bay of Bengal.
Importance of Snow Fields & Glaciers of the Himalaya
Earth’s Radiation Balance: Albedo from snow. 
Attracting SW Monsoon: The difference in temperature between the Himalayan snow-fields and glaciers and the Indian Ocean pulls the South-West monsoon towards the Indian landmass during summer.
Key Indicator of Climate Change: Snow-fields and glaciers govern the climate system of the Indian land mass at regional and global scales. 
1. Sensitivity of snow-fields and glaciers to variations in temperature makes them a key indicator of climate change.

Mitigation and Adaptation Strategies

  • Addressing glacier retreat requires a multi-faceted approach, including reducing greenhouse gas emissions, enhancing climate resilience, and implementing sustainable water management practices.
  • International cooperation and local community involvement are essential to mitigate the impacts and adapt to the changing environment.

Source: TH