UNESCO Report on Mountains and Glaciers: Global Warming Impact
Why in the news
The report, issued on the first World Day for Glaciers, warns that warming is changing mountain ecosystems quickly and mostly irreversibly.
Key facts
- The last three years saw the largest glacier mass loss on record.
- Since 1975 glaciers (excluding Greenland and Antarctica) lost over 9,000 billion tonnes, an ice block the size of Germany.
- Black carbon darkens ice and speeds melting.
- A 2024 Nature study found a 7.79% fall in persistent snow cover from 1979 to 2022, mostly in spring and summer.
Changes in mountain regions
| Change | Effect |
|---|---|
| Permafrost thaw | Releases organic carbon; destabilises slopes, raising landslide risk |
| Rising snow-rain transition elevation | More rain than snow at lower heights; earlier melt |
| Melting glaciers and unstable permafrost | Greater risk of glacial lake outburst floods (GLOFs) |
Why it matters
- Water security: over 2 billion people depend on glacier water; flows become unpredictable.
- Sea level: glacier melt causes 25-30% of observed rise; glaciers lost 335 billion tonnes yearly in 2006-2016, adding nearly 1 mm a year.
- Each millimetre of rise can expose 300,000 people to annual flooding.
Way forward
- Immediate policy action, awareness and resource mobilisation.
Exam angle
- World Day for Glaciers: March 21.
- GLOF = Glacial Lake Outburst Flood.