Climate Change and Its Impact on Mountain Glaciers

Rising global temperatures are causing changes in mountain ranges worldwide. A recent UNESCO report marks the alarming rate of glacier melting, permafrost thawing, and erratic snowfall patterns. These changes threaten ecosystems and human populations reliant on mountain water resources.

Glacier Melting

Glaciers are melting at an unprecedented rate. The last three years have recorded the largest loss of glacier mass. Since 1975, over 9,000 billion tonnes of glacial mass have been lost. This is equivalent to an ice block the size of Germany. In 2024, glaciers lost 450 gigatons of mass, with notable losses in Scandinavia and North Asia. Factors like wildfires and dust storms contribute to accelerated melting by darkening ice surfaces, increasing solar absorption.

Accelerating Permafrost Thaw

Permafrost, ground that remains frozen for at least two years, is rapidly thawing due to rising temperatures. This thaw releases organic carbon into the atmosphere, exacerbating climate change. Permafrost also stabilises mountain slopes. Its melting increases vulnerability to erosion and landslides, posing risks to both landscapes and human settlements.

Decline in Snow Cover

Snow cover in mountain regions is decreasing, especially in spring and summer. A global decline of 7.79% in persistent snow cover was reported between 1979 and 2022. This reduction affects water availability in downstream areas, as less snow translates to less meltwater in warmer months.

Erratic Snowfall Patterns

The transition from rainfall to snowfall is shifting to higher elevations. Warmer climates are experiencing reduced snow cover depth and duration. Some mountain ranges now receive more rain than snow, resulting in earlier snowmelt and a decrease in the overall snow-covered area.

Significance of Changes

Mountains cover 33 million square kilometres and are vital for freshwater resources. Approximately 2 billion people depend on melting glaciers for water. Continued glacier melting could lead to erratic water flow, affecting water quality and availability. Furthermore, the risk of glacial lake outburst floods (GLOFs) increases, which have historically caused loss of life and property. Melted glaciers contribute to 25-30% of global sea level rise, exposing millions to flooding risks.

Questions for UPSC:

1. Discuss the implications of glacier melting on global sea levels and human populations.
2. Critically examine the role of permafrost in climate regulation and its impact on mountain ecosystems.
3. Explain the relationship between climate change and the decline in snow cover in mountain regions.
4. With suitable examples, discuss the risks associated with glacial lake outburst floods in the context of climate change.

Answer Hints:

1. Discuss the implications of glacier melting on global sea levels and human populations.

1. Glacier melting contributes 25-30% of the observed rise in global sea levels.
2. Between 2006 and 2016, glaciers lost 335 billion tonnes of ice annually, raising sea levels by nearly 1 mm per year.
3. Melting glaciers threaten freshwater supplies for approximately 2 billion people downstream.
4. Erratic water flow patterns can lead to water scarcity and quality issues.
5. Increased flooding risk from glacial lake outburst floods (GLOFs) can displace communities and damage infrastructure.

2. Critically examine the role of permafrost in climate regulation and its impact on mountain ecosystems.

1. Permafrost stores amount of organic carbon, which, when thawed, releases greenhouse gases into the atmosphere.
2. Thawing permafrost destabilizes slopes, increasing erosion and landslide risks in mountainous areas.
3. Permafrost plays a critical role in maintaining the integrity of ecosystems and habitats in mountain regions.
4. Its loss can lead to shifts in vegetation and wildlife patterns, affecting biodiversity.
5. Permafrost degradation can disrupt hydrological cycles, impacting water availability downstream.

3. Explain the relationship between climate change and the decline in snow cover in mountain regions.

1. Rising temperatures are causing reduction in snow cover, especially in spring and summer.
2. A global decline of 7.79% in persistent snow cover was observed from 1979 to 2022.
3. Warmer conditions shift the elevation at which precipitation falls as snow, affecting snow depth and duration.
4. Less snow results in reduced meltwater availability during warmer months, impacting water resources.
5. Erratic snowfall patterns can lead to earlier snowmelt, further complicating water management in affected regions.

4. With suitable examples, discuss the risks associated with glacial lake outburst floods in the context of climate change.

1. GLOFs occur when natural dams formed by glaciers fail, leading to catastrophic flooding downstream.
2. Historically, GLOFs have caused over 12,000 deaths and damage to infrastructure and farmland.
3. Examples include the 2002 GLOF in the Himalayas, which displaced thousands and destroyed villages.
4. Increased glacier melting due to climate change raises the risk of GLOFs, threatening communities and ecosystems.
5. Effective monitoring and risk management strategies are crucial to mitigate the impacts of GLOFs in vulnerable regions.