Glaciers are important for their beauty, cultural importance, ecosystem services such as water resources, economic value, and potential to raise global sea levels. This is an impassioned plea to recognise the value of our glaciers worldwide, and to protect them to the best of our ability.
Globally shrinking glaciers
Glaciers exist in pretty well every continent, and altogether have enough ice to raise global sea levels by about 32 cm 1,2. That’s excluding the much larger Antarctic and Greenland Ice Sheets, which have another 58 and 7 m sea level equivalent between them. But despite their small scale, glaciers are significant. They occupy pretty well every large mountain range, with glaciers in the tropics, around the edges of the large ice sheets, and the European Alps.
Globally, these glaciers are shrinking. They are losing more mass than is being replenished each accumulation season.
This mass loss is accelerating; glacier (excluding the Antarctic and Greenland Ice Sheets) now lose 266 billion tonnes of ice (Gt) per year, equivalent to 21% of the observed sea level rise. This is accelerating, leading to an acceleration in sea level rise3.
Why are glaciers important to society?
Glaciers are a beautiful part of our landscape
Glaciers are beautiful, and culturally important. They are a unique and special part of our Earth’s landscape. They shape our mountains and our environments, and bring spectacular scenery. They are central to the identity of many mountain communities. Their shrinkage and recession remains one of the most visible impacts of climate change.
Figure 4. Photographs of Juneau Icefield, Alaska
Glaciers are also sites of powerful sacred and symbolic meanings. Mountains are often believed to be the abodes of important gods and deities 4. African tribes living at the base of Mount Kilimanjaro view the mountain’s ice cap as a ‘house of God’ to be adored from a distance. In the Himalayan Bhutan, people view the high peaks to be abodes of the Gods, and in the Peruvian Andes, the local Quecha prophesy argues that the world will end when snow disappears from Ausangate 4.
Glaciers are important for tourism and GDP
Glaciers are draws for tourists worldwide. From cruise ships in Juneau, Alaska to skiers in Tignes, France, people flock to see, ski on and climb the world’s mountain glaciers.
These tourists bring economic value to the local community5. More than USD$81 million per year is directly contributed to the economy by tourists associated with glaciers in New Zealand. This tourism provides employment opportunities and infrastructure and buildings may benefit local communities. Nepal could see a 10% loss in GDP from glacier melt, aggravated by increasing glacier hazards.
Glacier recession changes glacier hazards
As glaciers recede, we can see hazards developing in glacier forelands. These include avalanches and rockfalls from destablised slopes and indirect hazards, such as glacial lake outburst floods and debris flows. The destabilising impact of glacier recession can make hazards more frequent, impacting people more often.
In Pakistan, climate change is altering the landscape, driving glacier melt and putting thousands of people at risk of lake outburst flood or landslide.
Glacier change can challenge sovereign territory
Many national borders are driven by glaciers. Often these follow the topographic highpoints. As glaciers thin, this can mean nation-state boundaries being redrawn, as has recently happened in Switzerland and Italy as glaciers thin. Changing glaciers could exacerbate geopolitical tensions and increase antagonism between countries.
Glaciers are a water resource
Worldwide, glacierised basins cover 26% of the global landsurface (outside of Greenland and Antarctica), and are often densely populated.
These mountains are the ‘water towers’ of the world and provide water resources to up to 1.9 billion people worldwide.
As they shrink, meltwater may become temporarily more available, and this may help to buffer droughts and sustain river flows. However, as glaciers shrink, this natural reserve is depleted, and the ability of glaciers to sustain baseflows lessons. This can lead to more droughts, and a decreased ability to use the river flow for hydropower, irrigation, industry, and domestic consumption.
Loss of these water resources would increase climate change refugees and migration away from mountain environments globally. Increased scarcity of resources that cross national boundaries (such as water resources) could increase geopolitical tension, especially in parts of the world where boundary disputes have occurred in recent past and tensions remain high.
Glaciers support biodiversity
This meltwater also provides important ecosystem services; mountains are biodiversity hotspots, hosting a range of diverse habitats. About half the world’s biodiversity hotspots are located in mountains. Wetlands in high mountains can provide ecosystem services including carbon storage and pasture 6. The biodiversity of mountains is threatened by warming temperatures, and the resulting glacier recession is driving rapid ecosystem shifts 7. Many specialist species would be threatened by glacier loss 8.
Glaciers contribute to sea level rise
Glaciers are melting and the runoff is draining into the ocean, raising global sea level. Glaciers contributed about 24% of observed sea level rise, 1993-present 9,10. Increasing sea levels would lead to climate change refugees fleeing low lying areas, loss and destruction of coastal infrastructure, and billions of pounds spent on flood defences across the UK alone.
What is the future of glaciers?
Are we heading to a world without glaciers?
Global emissions policies after COP29 in November 2024 suggest that we are far off track for a 1.5°C of warming target.
A temperature rise of about 2.5-3°C by 2100 would be catastrophic for the world’s glaciers. This would mean the near complete deglaciation of central Europe, western North America and New Zealand11. The important water towers of the Himalaya and the tropical Andes would be strongly impacted by temperature rises of this magnitude.
How can we save the glaciers? Reasons to be optimistic
There is good news. The UK emissions have fallen dramatically in recent years as we switch to more renewable sources of power generation. The CarbonBrief states that UK emissions in 2023 fell to the lowest since 1879. This has been driven by falling demand for gas and coal, and the decommissioning of UK coal power plants. Importantly, this was achieved alongside increasing GDP; the UK is decarbonising as the economy grows.
Climate Action Tracker states that global action has reduced emissions and led to policy changes since 2015 that have reduced changes to estimated global temperature by 2100 by 0.9°C 12. Policy change remains the most important tool in our arsenal to reduce carbon emissions, which could make a real and important difference in how much glacier ice we have left at the end of this century.
Figure 14. Change in global temperatures projected in 2100 as a result of policy change, 2009 to 2024. Climate Action Tracker.
What can we do personally?
While we can do various things to cut our personal carbon emissions, like walking and cycling journeys less than two miles, switching to a renewable energy tariff, reducing meat and diary consumption, recycling, it is clear that the biggest wins are from policy induced changes to cut national emissions. The role of the government in reaching Net Zero cannot be overstated. Personal responsibility for climate change is deflecting the responsibility of large emitters and government.
The UK Climate Change Committee, an independent advisor on tackling climate change, argues, among other things, that the government needs to make energy cheaper, reverse recent policy rollbacks, remove planning barriers for heat pumps, electric vehicle charge points and onshore wind, decarbonise public sector buildings, and ramp up tree planting and peatland restoration.
For citizens, the most important things that we can do remain to educate, advocate, vote, and raise this issue repeatedly with politicians.