Going Downhill: The Olympic Race Against a Receding Snow Line
How elevation-dependent climate change is melting the mountain cryosphere, threatening high-altitude biodiversity, water security and pushing the Winter Olympics to the brink of extinction.
Set against the anticipation and excitement of the 2026 Winter Olympics, the poor state of mountain snow and ice makes for a depressing set of statistics. Between 2000 and 2023, global glaciers (not including Greenland and Antarctica) lost an average of 273 billion tonnes of ice each year, and it’s accelerating. Relative glacier loss was greatest in Central Europe and the Caucasus, which have lost 39% and 35% of their ice since 2000. Snowpack has followed a similar trajectory, declining globally in both thickness and duration.1 The ESA Climate Change Initiative (Glaciers) has some excellent data and visualisations.2
Behind the statistics, the evidence is clearly visible as the above images shows. When I visited Norway in 2011 and took the middle photo, it had already shrunk considerably from the 2001 image. I was shocked to find the 2025 image to be so much worse, even though I’d been expecting it (And before you ask, no I didn’t fly there in 2011). As well as the obvious retreat of the glacier tongue, note the reduction in height against the rock face at the top of the images.
The future will be determined by our continued carbon emissions and the warming they generate. Some areas, such as Scandinavia and western North America, will lose all or nearly all of their ice at 2°C of warming. Even the higher central and eastern parts of High Mountain Asia are projected to lose 60% of existing ice, even under a 1.5°C emissions scenario, with only 15% remaining at 3.0°C.
The impacts of this loss include water, food, economic and political insecurity, and should be considered essentially permanent on human time scales. These should all be treated as unacceptable risks.
Elevation Dependent Climate Change
Although global average temperatures are rising quickly, and are indeed now approaching 1.5°C, some regions of the world are warming faster than others. In the Arctic for example, the process of Arctic Amplification is driving temperature increases up to 4 times faster than the global average. Since high elevation and mountain regions share similar characteristics as polar regions in terms of albedo and vegetation feedbacks, they too show faster warming rates, ~50% higher than the global average.
Climate changes in mountain environments are highly complex. A international review study led by Dr Nick Pepin from the University of Portsmouth in the UK, dives into the topic.3
Temperature
Two types of mountain warming are evident. Firstly there is the general increase in warming rate with elevation, primarily caused by increased downwelling long wave radiation due to increased specific humidity. Secondly, a peak warming rate occurs at or near the annual average 0°C line. This tends to be the altitude of the snowline and is susceptible to the most changes in albedo as the snow ages and melts, allowing the elevation band to warm faster. Both provide Elevation Dependent Warming which has caused mountain regions to warm 0.21°C more than lowlands as a global average.
Reductions in aerosol loads, as local industry and transport becomes cleaner, can increase the solar energy reaching the surface. Although sometimes transported to high altitudes, aerosols usually affect low elevations more strongly, so their reduction causes increased warming at lower elevations. Owing to the different balance between surface albedo, specific humidity and changes in other variables, the shape of the curve of temperature trend versus elevation will vary spatially and temporally (both day/night and seasonally).
Precipitation
Mountain precipitation is often driven by air flows moving up the side of the mountain on the windward side. As the air is uplifted, it cools, eventually reaching the Lifting Condensation Level (LCL). Peak precipitation occurs around this level diminishing as the altitude rises higher. As the region warms, that LCL rises with it to higher and higher altitudes. Not all air packets reach the LCL so don’t rain out. As temperatures rise therefore, less precipitation occurs at the lower altitudes.
Rising temperatures will also cause an increase in total precipitable water in the atmospheric column, meaning more water is available to increase snow and rainfall. These variables play off against each other to alter the normal rainfall patterns across a mountain region, often bringing more extreme rain and snow fall to new areas as temperatures rise. Changes in upslope anabatic winds, which contribute to moist air lifting well above the LCL, or downslope katabatic winds add to the complexity of the changes.
Snow cover and albedo
As snow and ice melts in the warmer temperatures, the snowline retreats to higher altitudes. The high albedo snow and ice is then replaced with lower albedo rock and vegetation. This allows more local warming since the ground cover is more absorbent of the sun’s shortwave radiation. The largest changes are at the snowline which creates local warming pushing the snowline further in a Snow Albedo Feedback mechanism, similar to that found in the Arctic regions.
There is also a total mountain range albedo reduction since the overall area covered in snow and ice is reduced, effecting the whole energy imbalance of the planet. Although a relatively small contribution to the overall Earth Energy Imbalance, it pushes it in the wrong direction, accelerating the overall rate of global warming.
Albedo changes also occur at the treeline as higher albedo grass and bare surfaces are replaced by lower albedo alpine vegetation and forest tree cover. In many regions the seasonal snowline and treeline can overlap reducing overall albedo even further.
Other variables
In addition to the big three of temperature, precipitation and albedo changes, other variables are less well constrained, but have impacts on Elevation-Dependent Climate Change (EDCC). Specific Humidity is known to increase with temperature but the effect will be greater at higher altitudes since the proportional change is greater. This could lead to more cloud formation at higher altitudes with effects on precipitation and cloud albedo.
Surface wind changes are expected with EDCC including an intensification of daytime upslope winds and a weakening of night-time downslope winds. These will also be effected by changes in ground cover, especially the treeline position.
Industrial aerosol emissions such as black carbon and sulphates are reducing with strengthening clean air initiatives (in most countries) and the electrification of transport. This could increase surface albedo by reducing the fall out on snow surfaces, especially at lower altitudes. Increases in aerosol emissions and soot from increasing forest fires however, drive albedo loss.
Solar radiation is suggested to decline as cloud cover at higher altitudes increase, however globally, cloud cover is reducing and it remains to be seen whether this trend affects mountain regions.
The figure below (from the paper), summarises the various drivers and influences on mountain climate change.
Numbered from 1 to 13, the image shows the various processes under way as the climate warms. + and – indicate increasing and decreasing warming and climate effects, respectively.
Upper-level prevailing winds, changed by global climate change, interact with the mountains. Prevailing winds create windward and leeward effects that interact with the topology.
Change in cloud base height and moisture content, with associated heavy precipitation and changes in forest cloud elevation.
Changes in cloud properties and specific humidity, which reduce incoming solar energy but increase downward long wave trapped energy.
Strengthening upslope anabatic winds and weakening downslope katabatic winds.
Increasing streamflow extremes and variability due to higher rainfall and rain on snow events.
Glacier retreat influencing downstream fluvial regimes and habitats. Rising risk of glacial lake outburst floods.
Increase in snowline elevation and changes in snowpack above the snowline.
Snow albedo decrease through snowline movement, aging and melting.
Migration and possible expansion or contraction of vegetation zones upslope, and changes in vegetation composition, including from wildfire.
Anthropogenic aerosol declines, but wildfire aerosol increases, both effecting cloud formation and albedo.
High-elevation plateau creating mass elevation effects and reduces the influence of free-air processes.
Changing frequencies of temperature inversion formation and cold-air pools in mountain valleys.
Permafrost degradation leading to emissions, erosion and vegetation changes.
As is often the case with climate impacts and feedbacks, most of the processes tend to amplify mountain changes rather than dampen them.
The Pepin paper describes the observed and modelled trends in the world’s major mountain regions. There is a lot of variation between them, as you’d expect, but in all cases the trend is towards continued rapid warming with significant ice and snow loss, in agreement with the State of the Cryosphere reports.
The Water Towers Crisis and “Peak Water”
Mountains are often called the world’s “natural water towers.” While glaciers are the visible part, the entire mountain system provides and regulates water for billions of people downstream. 60% of the world’s freshwater supply originates in mountain regions. The High Mountain Asia (HMA), or Asia Water Tower, has the largest glacier area outside the polar regions, encompassing over 97,590 km2 approximately 30% of the mountain glaciers area of the world. The valuable freshwater from the glacier melt to many prominent rivers in the HMA meets the requirements of nearly 2.5 billion people, as well as agriculture irrigation and industrial uses. Their reliability is essential.4
As glaciers melt, water flow increases, however a point is reached where “peak water” occurs.5 After this point, due to there being less ice available for melting, the water supply drops away. According to the 2025 UN Water Development Report, peak water has already been passed in the glacial-fed rivers of the tropical Andes, western Canada and the Swiss Alps. Meanwhile, many glaciers have disappeared entirely. For example, Colombia has lost 90% of its glacial area since the mid-19th century.
The “Snow Dam” Effect is different from peak water, which is a long term trend linked to glacial mass balance. Traditionally, snow acts as a seasonal dam, storing water in winter and releasing it slowly in spring and summer. Warming is turning snow to rain, causing winter floods and summer droughts, disrupting agriculture for 25% of the global population. Elevation dependent warming is accelerating this process in the world’s mountains.
In a study published in January by Kai Liu et al. the High Mountain Asia water tower was found to be losing over 24Gt of ground water storage a year.6 47% of the ground water storage variability was found to be due to climate changes with an additional 15% contribution by the cryosphere, especially permafrost degradation. 38% of the losses are however due to unsustainable human extraction for cities and agriculture. Although peak water has not yet been reached, offsetting some of the severity of imminent reductions, this is predicted within 30 to 40 years, after which glacial melt flow will start to reduce. This will combine with the other factors creating a rapid and worrying decline, affecting billions locally as well as disrupting global food supply chains.
Thawing Permafrost and “Mountain Collapse”
Glacier decline gets most of the press, but mountain permafrost is the “invisible glue” holding high-altitude peaks together. Multiple permafrost areas in European mountains including the Alps, Scandinavia, Iceland, the Sierra Nevada of Spain, and Svalbard are now warming by more than 1°C per decade, matching rates commonly found in Arctic lowlands.
In addition to releasing greenhouse gases as they thaw, melting permafrost on mountain sides is destabilising, as witnessed in Blatten, Switzerland last year. Melting permafrost above the Birch glacier caused rockfalls that amassed sufficient additional weight to cause the glacier to catastrophically fail. Additional meltwater from the permafrost also served to lubricate and weaken the glacier ahead of the failure.
Also visible in the image from Blatten above, is the dam the landslide has created, forming a lake upstream in the valley. This has created the potential for a landslide dam outburst flood when the water pressure above the dam is sufficient to break through, flooding the region below. A similar thing can happen with Glacial Lake Outburst Floods (GLOFs). In these cases, water builds in a lake above an ice dam consisting of a glacier wall. The dam weakens as it melts, eventually releasing the lake water.
In 2023 a GLOF on the Test River in India killed 30 people as a 5-6m high water surge crashed down the valley. A hydroelectric facility was also destroyed. In fact, GLOFs alone have resulted in more than 12,000 deaths in the past 200 years, and have caused severe damage to farmland, homes, bridges, roads, hydropower plants and cultural assets. The total area and number of glacial lakes have increased significantly since the 1990s as glaciers have receded. More of these lakes will develop over the coming years, creating new hotspots of potentially dangerous GLOF hazards and risks.
Stäubli et al. calculated that the absolute economic losses in mountain regions across 713 events between 1985 and 2014 exceeded US$56 billion, affected over 258 million people and resulted in over 39,000 deaths.7 Increases in population and urbanisation in mountain regions may also increase the exposure of people and property to geohazard events and associated loss and damage. Just last summer over 1,000 died in Pakistan when extreme mountain rainfall led to divesting floods.
The Kai Liu study also noted that as the High Mountain Asia region loses glacier mass, high elevation lake formation will grow, increasing the risk of GLOFs, especially in the interior Tibetan Plateau and the upper Amu Darya basin.
From an Olympic perspective rockfalls, permafrost melt and growing instability threatens the very infrastructure used for the Olympics, like cable car foundations, mountain huts, and high-altitude railways.
The “Stairway to Extinction”
The vast majority of both animal and plant species have evolved to thrive in particular climate envelopes. As temperatures rise, alpine species move further up the mountain chasing cooler conditions. This doesn’t just effect a few specialist species, mountain regions globally are home to 85% of bird, amphibian and mammal species. Global biodiversity is therefore under pressure.
A Summit Trap exists when a species literally runs out of mountain to climb, chasing their ideal habitat further and further up until they reach the summit. Species like the Pika or certain alpine flowers have already reached the peak. They have nowhere higher to go - this is known as the “escalator to extinction.”
In addition to shifting climate niches, warming can also cause plants to bloom before the specific insects that pollinate them have emerged, breaking ancient ecological links. This has a knock on effect for the birds that rely on the insects, and on up the trophic levels.
The “Climatic Debt” of Mountain Cultures
Mountain communities have unique cultural identities tied to the “permanence” of the ice.
Elevation dependent climate change therefore creates an intangible loss as well as a physical one. For many indigenous groups (like those in the Andes or Himalayas), glaciers are deities or ancestors. Their disappearance is a form of cultural trauma.
The UN water report links mountain resources in the form of snow, permafrost, lake and river ice and glaciers to the Sustainable Development Goals in the chart below.
Rotating the chart 90º anticlockwise creates a pyramid with the SDGs at the top, all being supported by the mountain cryosphere at the base. This really shows the precariousness of the position humanity is in unless we do all we can to preserve the natural balance as much as possible.
In a similar pattern to peak water, a “last chance tourism” phenomenon is emerging where people flock to see glaciers before they vanish, creating a bittersweet economic boom that is inherently unsustainable. It’s already too late to see tropical coral reefs in their past glory, glaciers and mountain vistas are next.
The Uncertain Future of the Winter Olympics
One of the most visible impacts of EDCC is in winter sports and especially the Winter Olympics, due to start this weekend in Italy. Two studies have been released in the last two years examining the uncertain future of the games and suggesting measures to keep it on life support for a few more decades at least.89
Trouble started in 2010 when officials in Vancouver had to fly in huge quantities of snow to create the snowboarding and freestyle runs. The 2014 games in Sochi saw unusually high injury rates due to slushy conditions. By 2022 the Beijing games were almost exclusively carried out on artificial snow, with much criticism of the environmental and emissions impacts.10 This year’s games will has still required 2 million tonnes of artificial snow despite the altitude and more reliable snow in the region.
The two studies examined the prospects of the 93 regions that have previously hosted the games and found that only 22 would meet the requirements of the Olympics and Paralympics by 2050 (just 5 games cycles).
The most effective suggestion is to hold the games earlier in the year, but this could cause problems for broadcasters and volunteer availability. Abandoning the “one bid, one city” rule where both the winter games are hosted by the same city, even rotating the games between a handful of surviving hosts is being discussed. Making artificial snow more sustainable will also be critical to the future of the games.
There is a slender silver lining to the Olympic cloud however. It could bring the facts of climate change and the plight of mountain regions to a global audience. It allows the public, especially in the wealthier regions, to be faced with reality and provides the media and commentators with an opportunity to explain the facts and impacts of climate change. We’ll see if they take this opportunity over the coming weeks…
ICCI, 2025. State of the Cryosphere 2025: Ice Loss = Global Damage. International Cryosphere Climate Initiative (ICCI), Stockholm, Sweden. 52 pp. https://iccinet.org/statecryo25/
The ESA Climate Change Initiative (Glaciers) has some excellent data and visualisations. https://climate.esa.int/en/projects/glaciers/
Pepin, N., Apple, M., Knowles, J. et al. Elevation-dependent climate change in mountain environments. Nat Rev Earth Environ 6, 772–788 (2025). https://doi.org/10.1038/s43017-025-00740-4
United Nations, The United Nations World Water Development Report 2025 – Mountains and glaciers: Water towers. UNESCO, Paris. https://www.unwater.org/publications/un-world-water-development-report-2025
IPCC Special Report on the Ocean and Cryosphere (Chapter 2: High Mountain Areas). https://www.ipcc.ch/srocc/chapter/chapter-2/
Kai Liu et al, Assessing groundwater sustainability across high mountain Asia using remote sensing, Environmental Research Letters (2026). https://iopscience.iop.org/article/10.1088/1748-9326/ae2e1b
Stäubli, A.,et al. 2018. Analysis of weather-and climate-related disasters in mountain regions using different disaster databases. S. Mal, R. Singh and C. Huggel (eds), Climate Change, Extreme Events and Disaster Risk Reduction: Towards Sustainable Development Goals. Cham, Switzerland, Springer, pp. 17–41. doi.org/10.1007/978-3-319-56469-2_2.
Steiger, R., & Scott, D. (2025). Climate change and the climate reliability of hosts in the second century of the Winter Olympic Games. Current Issues in Tourism, 28(22), 3661–3674. https://doi.org/10.1080/13683500.2024.2403133
Scott, D., Steiger, R., & Orr, M. (2026). Advancing climate change resilience of the Winter Olympic-Paralympic Games. Current Issues in Tourism, 1–8. https://doi.org/10.1080/13683500.2026.2617880
Slippery Slopes: HOW CLIMATE CHANGE IS THREATENING THE WINTER OLYMPICS https://www.sportecology.org/_files/ugd/a700be_9aa3ec697a39446eb11b8330aec19e30.pdf
Yet another great article Tom. Am contemplating putting up Cryocrier or Albedo Brief ( like Carbon Brief ) to give daily cryosphere and albedo news.