Threats to Glaciated Landscapes

Glaciated landscapes face a range of threats from both natural processes and human activities. Climate change is the most significant and far-reaching threat, but tourism pressure, resource extraction and infrastructure development also pose serious challenges. This lesson addresses Edexcel A-Level Geography Enquiry Question 2 (EQ2) by examining how these threats interact and impact glaciated environments.

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Climate Change: The Primary Threat

Glacier Retreat

Global warming is causing widespread glacier retreat:

Region	Rate of Change	Key Data
European Alps	Rapid retreat	Lost ~60% of ice volume since 1850; Switzerland's glaciers lost 10% of remaining volume in 2022 and 2023 alone
Himalaya	Accelerating retreat	Glaciers melting ~65% faster since 2010 compared to 2000–2009 (ICIMOD, 2023)
Greenland Ice Sheet	Mass loss accelerating	Losing ~280 Gt/year (2006–2018); contributed ~13.7 mm to sea level rise since 1972
Tropical glaciers	Near elimination	Kilimanjaro has lost ~85% of its ice cover since 1912; Peruvian glaciers retreated ~30% since 1980
Arctic glaciers	Widespread retreat	Svalbard glaciers thinning; Alaska glaciers losing ~75 Gt/year
Antarctic Peninsula	Ice shelf collapse	Larsen B Ice Shelf collapsed in 2002 (~3,250 km²); Thwaites Glacier at risk

Consequences of Glacier Retreat

Consequence	Impact	Scale
Sea level rise	Glacier melt contributes to global sea level rise	~21 mm since 1961 from glaciers alone (excluding Greenland/Antarctic ice sheets)
Water insecurity	Reduced glacier storage → less reliable dry-season water supply	Affects ~1.9 billion people in Himalayan, Andean and Central Asian regions
Glacial lake formation	Retreating glaciers leave moraine-dammed lakes	Growing risk of GLOFs (see below)
New landscapes	Glacier forelands exposed to weathering, erosion and colonisation	Opportunities for ecological succession research
Loss of scientific record	Glaciers contain climate archives that are being lost	Irreversible loss of palaeoclimate data
Cultural loss	Glaciers are central to Alpine, Arctic and Andean cultures	Loss of identity and heritage
Tourism change	"Last chance tourism" increases pressure; ski industry threatened	Economic restructuring required

Exam Tip: When discussing the impacts of glacier retreat, always consider scale (local, regional, global) and timescale (short-term, long-term). The impacts on sea level and water supply are global and long-term; the impacts on tourism and culture are regional and more immediate. This multi-scale analysis is essential for top marks.

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Permafrost Thaw

As discussed in Lesson 7, permafrost thaw is a critical consequence of climate change with wide-ranging impacts:

Infrastructure Damage

Location	Impact	Detail
Russia (Siberia)	Building collapse	~40% of buildings in some Siberian cities (e.g., Norilsk, Yakutsk) are experiencing structural damage from permafrost thaw
Alaska	Road and pipeline damage	The Dalton Highway and Trans-Alaska Pipeline require continuous monitoring and adaptation
Canada	Airport and building damage	Inuvik and other northern communities experiencing foundation instability
Svalbard	Seed vault threat	The Svalbard Global Seed Vault experienced unexpected meltwater ingress in 2017 due to permafrost warming

Carbon Release

The permafrost carbon feedback loop is one of the most concerning aspects of Arctic warming:

• 1,500 Gt of carbon stored in Arctic permafrost (twice the current atmospheric content)
• Thawing releases CO₂ (aerobic decomposition) and CH₄ (anaerobic decomposition)
• Current estimates suggest permafrost thaw could release 50–100 Gt of carbon by 2100 under moderate warming scenarios
• This is equivalent to approximately 5–10 years of current global fossil fuel emissions
• Creates a positive feedback loop that could accelerate warming beyond current projections

Slope Instability

Permafrost thaw destabilises slopes, increasing the risk of:

• Landslides and rockfalls in mountain areas (e.g., the 2017 Bondo landslide in Switzerland — 3 million m³ of rock, partly attributed to permafrost degradation)
• Coastal erosion — Arctic coastlines are retreating rapidly as permafrost bluffs thaw and collapse (e.g., the Beaufort Sea coast of Alaska is retreating at up to 15–20 m per year)
• Solifluction — accelerated downslope soil movement

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Glacial Hazards

GLOFs (Glacial Lake Outburst Floods)

GLOFs occur when a moraine-dammed glacial lake bursts, releasing enormous volumes of water in a catastrophic flood. The frequency of GLOFs is increasing as glacier retreat creates more and larger moraine-dammed lakes.

Event	Location	Impact
Dig Tsho GLOF (1985)	Langmoche, Nepal	Destroyed the Namche Small Hydro Plant and 14 bridges; 5 deaths
Lake Palcacocha GLOF (1941)	Huaraz, Peru	Killed approximately 1,800–6,000 people; destroyed one-third of the city
Chamoli disaster (2021)	Uttarakhand, India	Rock and ice avalanche triggered a debris flow/GLOF; killed ~200 people; destroyed two HEP plants