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Context :

• Recently, A new UNESCO report shows how global warming is accelerating the melting of glaciers, melting of permafrost, reduction of snow cover & irregular snowfall patterns in mountain ranges around the world.
• The report was released on the 1st World Day for Glaciers on March 21, 2025.
• It also highlights rapid & largely irreversible changes to mountain ecosystems caused by rising temperatures.

Key Findings from the Report

1. Glacier Melting

• Glaciers are disappearing at unprecedented rates.
• largest glacial mass loss was recorded over the last 3 years.
• Since 1975 glaciers (excluding Greenland & Antarctica) have lost over 9,000 billion tonnes of mass. It is equivalent to an ice block the size of Germany with a thickness of 25 meters.
• Accelerating loss: The last 6 years have seen the largest losses. 450 gigatons lost in 2024
• Impact of Impurities: The deposition of black carbon & other particulate matter from wildfires & dust storms darkens snow & ice surfaces. It is increasing solar radiation absorption. And it is also leading to more rapid melting.

2. Accelerating Permafrost Thaw

• Permafrost ground that remains frozen for at least 2 years. It is rapidly thawing due to rising temperatures in high altitude regions.
• Organic carbon release: Thawing permafrost releases 5% of the global soil organic carbon. It is contributing to increased greenhouse gas emissions & exacerbating climate change.
• Impact on stability: As permafrost melts then mountain slopes become more unstable. Because it is increasing the risk of landslides & other hazards.

3. Decline in Snow Cover

• Snow cover in mountain regions has been consistently declining in spring & summer. And further decreases are expected in the coming decades.
• A study published in Nature (2024) found a global mean decline of 79% in persistent snow cover between 1979 & 2022.

4. Erratic Snowfall Patterns

• The transition elevation between rainfall & snowfall is shifting upward due to atmospheric warming. It is also reducing the depth & duration of snow cover at lower elevations.
• Increased rainfall: Some mountain ranges now experience more rain than snow with earlier snowmelt & reduced snow covered areas.

Why Is This Significant?

1. Impact on Water Resources

• Mountains are important as water towers. They provide freshwater for 2 billion people downstream who depend on melting glaciers.
• Glacier melting & erratic water flow can result in:
  • Increased erosion & sediment loads.
  • Changes in the timing & volume of water flow. It is affecting water quality & availability

2. Increased Risk of Glacial Lake Outburst Floods (GLOFs)

• GLOFs occur when natural dams formed by glaciers or ice break. It is causing catastrophic floods.
• These floods have caused 12,000 deaths in the past 200 years. and It is significant damage to infrastructure, including farmland, homes, roads, & hydropower plants.

3. Contribution to Rising Sea Levels

• Glacier melting accounts for 25-30% of the current rise in global sea levels.
• From 2006-2016 glaciers lost 335 billion tonnes of ice They are contributing to a 1 mm per year rise in sea levels.
• Even a 1 mm rise can expose up to 300,000 people to annual flooding.

What are the Global Implications ?

• The changes in mountain ranges due to global warming are affecting millions of people
• Because temperatures rise, we face increasing challenges in managing water resources, natural hazards, & climate induced displacement.
• Raising awareness & taking urgent action is critical to mitigating these impacts. It is affecting everyone  from local communities to global populations.

Source: IE