Why should we preserve glaciers?

19 March 2025 | By: Newcastle University | 7 min read

Vaughan Lewis Icefall and down Gilkey Glacier, Alaska

Glaciers matter. They play a crucial role in regulating Earth’s climate, storing freshwater, and sustaining ecosystems.

Nearly 2 billion people rely on water from glaciers, snowmelt and mountain run-off for drinking, agriculture, and energy production (UN-Water/UNESCO). Yet, due to rising global temperatures, glaciers are retreating at an unprecedented rate, threatening both people and the planet.

As 2025 marks the UN’s International Year of Glaciers' Preservation, experts from Newcastle explain why glaciers are vital to our planet, how we can slow their retreat, and the consequences of inaction in a warming world.

Why are glaciers important? - Professor Bethan Davies
Climate injustice: living beside the most dangerous lake in Bhutan - Sonam Rinzin
Himalayan meltwater: a dangerous lifeline in a changing climate - Niamh Hope
Recent research and further reading

Why are glaciers important?

Bethan Davies, Professor of Glaciology, writes about the vital importance of glaciers, the terrible cost of glacial loss, and how we can preserve them.

The importance of glaciers

Worldwide, glaciers are shrinking. Everywhere we look, glaciers are getting smaller each year; they are melting and losing more ice than they are gaining from snowfall or other solid precipitation.

The loss of glaciers is a loss for society.

Glaciers are beautiful in their own right, forming some of our world’s most inspiring landscapes. They have a cultural importance, being revered by mountain and polar communities in different regions across the world. They have economic importance and value; glaciers bring in funds through tourism and adventure travel.

But most importantly, glaciers provide ecosystem services.

As they melt, they maintain the river flow down-valley, especially in dry seasons and even more importantly in drought years. This melt eventually makes its way to the sea, where it contributes to the rise of global sea levels.

The cost of glacier loss

Avalanche Canyon, with Gilkey Glacier in the background. Juneau Icefield, Alaska. Credit: Bethan Davies, 2022.

Worldwide, glaciers separate from the large Antarctic and Greenland ice sheets now lose a total of 266 billion tonnes of ice every year, driving 21% of currently observed sea level rise. In the UK alone, by the 2080s, over 100,000 properties may be at risk from coastal erosion, and estimates of sea level rise by 2100 are 0.8 to 2.6m under current climate policies.

Currently, coastal flooding costs £500 million per year, and costs will rise under sea level rise. Replacing the Thames Barrier and sea defences protecting London, required by 2070 CE, could cost more than £20 billion.

Globally, the rising sea levels would mean that the current 1-in-100-year flood events could occur at least annually in half of tide gauges worldwide. With global coastal populations exceeding 600 million people, many millions of people would be displaced by 2050 CE, leading to increased migration driven by climate change.

Glacial meltwater is a lifeforce

In mountain regions of the world, communities rely on glacier meltwater.

Glacierised basins worldwide cover 26% of the global land surface, and many are densely populated. The mountain ‘water towers’ of the world provide water resources to up to 1.9 billion people worldwide as a result. This water is used extensively for irrigation, hydropower, industry, and domestic consumption.

Mountains are also biodiversity hotspots, with meltwater supporting a range of important and diverse habitats. As the glaciers shrink, water shortages are exacerbated, especially during drought years. With many millions of people affected, this would increase climate change migration and refugees.

How can we preserve glaciers?

Snowfall occurs frequently in the Cordillera Vilcanota, Peru. High solar radiation here rapidly melts this snow, except on glacier surfaces. Credit: Bethan Davies, 2023.

The most effective way to preserve glaciers is by reducing carbon dioxide emissions and curbing the rise in global heating.

While we can hypothesise about potential geoengineering solutions, none of these are tested and may cause more harm than good. All would require substantial investment in inhospitable and often politically contested parts of the world; funds that would be better invested in clean energy and transport.

Climate injustice: living beside the most dangerous glacial lake in Bhutan

Sonam Rinzin, Third-year Geography PhD student, writes about life close to Thorthormi Tsho, the most dangerous glacial lake in Bhutan, and the carbon-negative village that bears the brunt of climate change.

Glacier retreat and formation of dangerous glacial lakes

According to the latest study published in Nature, glaciers around the world have lost 273 billion tonnes of ice every year since 2000 - a rate that has accelerated alarmingly over the past decades due to climate warming.

This rapid melting of glaciers has led to the formation and expansion of numerous glacial lakes which are massive reservoirs of the meltwater. Some of these lakes threaten downstream communities with the risk of catastrophic floods, known as glacial lake outburst floods (GLOFs). Amongst the most vulnerable regions in the world is the remote village of Lunana in Bhutan. It is surrounded by retreating glaciers and is just three kilometres downstream from one of the world's most dangerous glacial lakes, Thorthormi Tsho.

Thorthormi Tsho: the most dangerous glacial lake in Bhutan

The Thorthormi glacier has retreated about 300m annually between 2000 and 2024, leading to the formation of the Thorthormi Tsho Lake, which is now about 4.3 km² in size.

In response to the rapid growth of this glacial lake and the looming threat of GLOF, the Royal Government of Bhutan initiated a project to lower the water levels of Thorthormi Tsho, which would reduce the magnitude of a GLOF. This successfully reduced the lake level by five meters between 2008 and 2013.

Thorthormi Tsho Glacial Lake, Bhutan. Credit: Sonam Rinzin.

However, since then, the lake has refilled to its previous level and has now become the largest and the most dangerous glacial lake in Bhutan. Although no field measurement of its volume has been conducted so far, scientists have estimated that it might be storing about 300 million cubic meters of water, which is 120,000 times bigger than an Olympic-sized swimming pool. If this lake produces GLOF in the future, it could produce a flow rate of about 70,000 m3 s-1 and arrive at the village of Lunana within 15 minutes.

A village bearing the brunt of a climate crisis caused by others

Lunana’s residents have endured four GLOFs since 1994, including a 2023 Thorthormi Tsho event that claimed lives, destroyed homes, and left lasting trauma.

Compounding their vulnerability, Lunana is Bhutan’s most isolated settlement. It’s a nine-day walk from the nearest road, with no basic modern facilities like a reliable source of electricity or proper sanitation.

The Lunana community. close to the Thorthormi glacial lake, the most dangerous glacial lake in Bhutan. Credit: Sonam Rinzin.

In response, the Royal Government of Bhutan has set up a GLOF early warning system, which covers Lunana and further downstream. However, the early warning system could do little to save lives in the case of a future GLOF, as the proximity of Lunana to this lake leaves very little time for evacuation.

In 2024, the government relocated two of Lunana’s communities, Toenchey and Thanza, to higher ground to mitigate future loss. While tents and drinking water were provided, the relocated families now face harsh conditions at 4,200 meters above sea level, enduring bone-chilling cold, overcrowded shelters, and inadequate sanitation. Many resent leaving ancestral lands, highlighting the painful trade-offs between safety and cultural identity.

Bhutan is one of the world’s few carbon-negative countries, absorbing more carbon than it emits. And its people, particularly in Lunana, have lived sustainably for generations. Their daily lifestyle intertwined with nature has left a minimal environmental footprint.

However, they now bear the brunt of a climate crisis they did little to cause.

This paradox underscores a global climate injustice. Communities like Lunana, which contribute negligibly to greenhouse gas emissions, face existential threats from rising temperatures, while wealthier, high-emitting nations remain insulated from the immediate consequences.

Himalayan meltwater: a dangerous lifeline in a changing climate

Niamh Hope, Environmental Geoscience Postgraduate Student, writes about her recent fieldwork in Bhutan, how meltwater in the Himalayas threatens communities, and what actions are needed to protect both glaciers and people.

Fieldwork in the Bhutanese Himalayas

I have long been fascinated by glaciers and the influence climate change has on them. My interest has been further sparked through glacier research as an undergraduate and master’s student here at Newcastle University.

In September 2024, I was fortunate to go on fieldwork to Lunana in the Bhutanese Himalayas, where I got to see first-hand the fragile nature of glaciers as they undergo substantial melt with global warming.

Niamh standing in front of the Raphstreng glacier and lake. Credit: Niamh Hope

Fieldwork camps in Lunana, Bhutan. Credit: Niamh Hope

Raphstreng Tsho Glacial Lake, Bhutan. Credit: Niamh Hope.

Meltwater can mean life or death

As they melt, the glaciers in Lunana serve as vital freshwater sources, supplying water to thousands of people downstream, including people living on the floodplains below. These glaciers have vast, breathtaking lakes which have developed at their terminus through melt. One of the lakes is even a beautiful turquoise colour.

But despite their beauty, they can cause catastrophic flood events if the natural sediment dams that surround them collapse.

Glacial Lake Outburst Floods (GLOFs) are common in the Himalayas and have previously occurred in Lunana. For example, a significant GLOF occurred in 1994 from Lake Lugge Tsho, leaving clear evidence along the valley sides where powerful water flows carved out parts of the landscape. Massive boulders were deposited alongside the river channel and across the floodplain, highlighting the destructive force of these events. Many people were also injured, and some were killed, with major damage to infrastructure and people’s livelihoods.

People still live on the flood path where future GLOFs may be routed, both directly below the glacier lakes and along the river's path up to 80 km downstream. Bhutanese people fear the chance of GLOFs every day and would ask us during the fieldwork if they need to rebuild their houses further away.

An increase in GLOF events worldwide

I was stunned at the thought that such beautiful natural features and processes could cause so much damage and destruction and create so much fear in people.

GLOF events are not only occurring in Lunana but can happen anywhere around the world in high mountain or ice-covered environments. These hazards will become more frequent and severe worldwide as climate change worsens.

An urgent global response to climate change is required to protect glaciers and people at risk from glacier-related hazards.

There are many ways to do this. This could include reducing our carbon footprint, supporting climate policies, or promoting conservation efforts. Potentially, the most important thing could be to educate and spread awareness to people about the influence of climate change on glaciers.

We must remember the scale of the danger caused by glacial loss. After all, it does not just pose a threat to the environment but also to humanity itself.

Discover some of our recent research

Why should we care about Himalayan glaciers?

Himalayan glaciers are not just icy landscapes, they are lifelines for millions of people and ecosystems across Asia.