Himalayas losing glaciers and snow: more hazards in the offing, a new study finds

Subject: Environment

Section: Climate change

Context:

A recent report on the effect of climate change on the Hindu Kush Himalaya warns of glacier volume loss of 30% to 50% by 2100.

Details:

The rapid melting of glaciers, snow and permafrost is making the mountain region more hazardous. More meltwater will be drained into the rivers till mid-century after which the water availability will steadily decline.
The ecosystem and societies in the region are facing a hard limit for adaptation if the global warming levels are allowed to escalate.

Water, ice, society and ecosystems in the Hindu Kush Himalaya or the HI-WISE report:

Released by Nepal-based International Centre for Integrated Mountain Development (ICIMOD).
The HI-WISE report follows the HKH Assessment Report (2019), which assessed literature published till 2017, focusing on aspects of climate change, cryosphere, water and biodiversity.
The report focuses on the cryosphere-hydrosphere-biosphere-society linkages in the Hindu Kush Himalayan region.
The HI-WISE report aims to inform the people of the Hindu Kush Himalaya, as well as decision-makers, practitioners and the global community on the rapidly changing cryosphere in the region and its impacts on water, biodiversity, and societies.
The report highlighted the ecosystem degradation and changes in species structure and composition.

Significance of Himalayan glaciers:

The Himalayas are known as the Water Tower of Asia, as Himalaya is the water source for 16 countries, including India and China, feeding over two billion people living in various river basins.
Even the people living downstream are heavily reliant on meltwater originating from mountains for agricultural, domestic, and industrial uses.

Karakoram anomaly:

A projected 30%-50% loss in glacier volume by the end of the century at the global warming level between 1.5 degrees Celsius to 2 degrees Celsius.
The Karakoram range, too, is losing glaciers, making the “Karakoram Anomaly” a thing of the past.
Karakoram Anomaly refers to the anomalous growth and stability of glaciers in central Karakoram, in contrast to the retreat of glaciers in other parts.
Consequences:
- It would result in increased water discharge into the rivers.
- More extreme weather events like glacier lake outburst floods (GLOFs) that happened in Chamoli or Melamchi are a possibility.
- The snow cover days have declined at an average rate of five days per decade with most of the changes at lower elevations.
- Seasonal shift in the snow cover with a notable decrease during the summer and winter months.

Climate change and permafrost thawing:

Permafrost is essentially any ground that stays frozen — 0 degree Celsius or lower — for at least two years straight.
These permanently frozen grounds are often found in Arctic regions such as Greenland, Alaska (the United States), Canada, Russia and Eastern Europe. Permafrost is also present in higher altitudes of the mountains like the Himalayas.
Thawing permafrost in the Himalayas has been reported to be a cause for impending climate disasters.
- Permafrost thaw makes surfaces, slopes and infrastructure unstable, making a good case for a change in government policies on large hydropower projects in the region.
- Permafrost thaw leads to increased sedimentation in rivers which damages dams and turbines.