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Alpine (Mountain) glaciers are in decline and are projected to continue shrinking under all emissions scenarios, with impacts on water availability, ecosystems, natural hazards, and sea-level rise. Glacier loss is already locked in due to past warming and cannot be rapidly reversed, but strong mitigation could still reduce its magnitude and pace. Overall glacial loss is similar in the near term but diverge substantially under higher-emissions pathways over the mid to long term. In general, smaller, thinner, and lower-elevation glaciers lose mass fastest, while larger and higher-elevation glaciers respond more slowly but are not immune to sustained warming.

This page visualizes historical glacier retreat and projections of future change across multiple spatial scales. It begins with a high-level synthesis of key findings (Section 1), followed by spatially-aggregated pixels, country and subnational future projections that offer localized insights into changes in glacier number, extent, mass, and annual mass loss (Section 2). The page then presents global and regional summary table (Section 3). The original dataset (Rounce et al., 2022) is provided at the glacier level as centroid points (longitude, latitude, with associated mass and area). CCKP has transformed the data onto a 0.25° grid to derive pixel-level counts, area, and mass, and has further aggregated it to country and subnational levels.

A central policy challenge is to slow the rate of loss, limit the most severe impacts, and anticipate critical thresholds, making near- and long-term glacier projections essential for effective adaptation planning at all scales.

 

Relevant references: 

  • David R. Rounce et al. (2023), Global glacier change in the 21st century: Every increase in temperature matters.Science 379,78-83. DOI: 10.1126/science.abo1324

  • Van Tricht, L., Zekollari, H., Huss, M. et al. (2025), Peak glacier extinction in the mid-twenty-first century. Nat. Clim. Chang. DOI: 10.1038/s41558-025-02513-9 ​

Note that the glacier projections shown here exclude the Greenland and Antarctic ice sheets, as they behave very differently from mountain glaciers and were not included in the original source.

01 - Key Findings

What has already happened?
Since 2000, the world has already lost around 6,500 Gt (Gigatons) of glacier mass (up to 2024). The first figure below shows the annual rate of glacier mass change and the cumulative mass change over the historical period.

 

What is projected to happen into the future?
Throughout the remainder of the 21st century, glaciers around the world are projected to keep losing mass. The rate of this loss will be heavily influenced by future greenhouse gas emissions. Under high-emission scenarios, by 2100, glacier mass loss is expected to be at least ten times greater than the total amount lost between 2000 and 2024, potentially reaching nearly 80,000 Gt.

 

The time series shows the observed global annual glacier mass change in Gt/yr - gigatons per year - in pink (left axis), along with the cumulative mass change since 2000 in Gt - gigatons - in black (right axis). Uncertainties are given as 95% confidence intervals.

 

 

See how, over the historical period, annual mass loss shows an overall increase. This indicates a general tendency toward faster loss rates over time (every time more negative), even though the rate does not increase every single year. Since 2000, the world has already lost around 6,500 Gt of glacier mass (up to 2024).

Glacier mass loss is closely related to water loss: assuming an ice density of approximately 0.9 kg/m³, annual mass loss can be multiplied by 0.9 to estimate the equivalent volume of water in cubic meters per year (1 cubic meter = 1,000 liters). 

Data from GlaMBIE (2024): Glacier Mass Balance Intercomparison Exercise (GlaMBIE) Dataset 1.0.0. World Glacier Monitoring Service (WGMS), Zurich, Switzerland. https://doi.org/10.5904/wgms-glambie-2024-07

 

The 2000 to 2100 time series shows projected global annual glacier mass change in Gt/yr (solid lines for different scenarios, select 'annual') or the cumulative mass change across scenarios, in Gt (select 'cumulative').

The four scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) can be removed/added from the plot by clicking on the legend.

The shaded areas represent the range between the 10th and 90th percentiles.

 

 

Glaciers around the world are projected to continue losing mass throughout the remainder of the 21st century. The pace of this loss will depend strongly on future greenhouse-gas emissions, particularly after 2040.

Under high-emission scenarios (SSP3-7.0 and SSP5-8.5), the annual rate of glacier mass loss is expected to continue increasing throughout the century.

Under low-emission scenarios (SSP1-2.6 and SSP2-4.5), the global rate of mass loss is projected to slow and stabilize—and may even begin to decline—before 2100.

The units are the same as those used in the historical observations above, allowing for direct comparison. 

By 2100, high-emission scenarios project at least ten times more glacier accumulated mass loss (from 2000 to 2100) than the total mass lost observed between 2000 and 2024.

Data from - Rounce, D.R., R. Hock, and F. Maussion. 2022. Global PyGEM-OGGM Glacier Projections with RCP and SSP Scenarios, Version 1. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/P8BN9VO9N5C7

The plot shows the projected global distribution of glacier mass across different years and scenarios (to be selected from the menu on the left). Note that the mass x-axis is logarithmic and expressed in Mt (megatons). Choose SSP to compare scenarios for a given year, or Year to compare different years within a given SSP. Scenarios or years can be removed/added from the plot by clicking on the legend.

Smaller glaciers are particularly vulnerable. Many of them are projected to shrink rapidly and disappear within the coming decades. Larger glaciers will persist longer but will continue to shrink over time.

As a result, the global glacier system will change significantly: ice mass will become concentrated in fewer glaciers, and the remaining glaciers will generally be smaller than today. This process is projected to occur faster for higher-emission scenarios.

Data from - Rounce, D.R., R. Hock, and F. Maussion. 2022. Global PyGEM-OGGM Glacier Projections with RCP and SSP Scenarios, Version 1. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/P8BN9VO9N5C7

This map shows, at the country and subnational level, the proportion of glacier mass projected to remain at different future times relative to the year 2000, for a given scenario. These proportions are represented by doughnut charts. The emissions scenario can be selected from the menu on the left, and the concentric rings correspond to four time horizons: 2025, 2050, 2075, and 2100 (see legend below).

The default view displays a comparison of countries within the region of the selected country. Zoom out to view the global comparison. When a subnational region is selected on the map, the doughnut charts switch to show differences between subnational areas within that country. To return to country view, click on a different country.

The base map shows the pixel-by-pixel number of glaciers in 2000.

The map illustrates how mass projections vary across countries and subnationals within countries, showing that all scenarios project glacier mass loss, but higher-emission scenarios lead to greater glacier mass loss at an earlier stage. While large mountain ranges in South Asia, North America, Greenland, and South America are projected to retain mass for a longer period, mountain ranges in Europe and other isolated areas will lose all their ice much sooner for all scenarios.

Data from - Rounce, D.R., R. Hock, and F. Maussion. 2022. Global PyGEM-OGGM Glacier Projections with RCP and SSP Scenarios, Version 1. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/P8BN9VO9N5C7

02 - Projected Local Glacier Decline

Here, we present glacier projections at the local scale in two formats: (1) maps and (2) spatially aggregated time series from 2000 to 2100.

 

By default, aggregated results are shown at the country level. Users can also select subnational units or explore projections for a specific location by choosing “PIXEL” from the menu and specifying a latitude and longitude.

 

Available variables include glacier count, area, and mass.

 

Selecting a country enables comparisons with other countries in the same region, while selecting a subnational unit allows comparisons among subnational units within the same country.

Users can choose to view Area, Mass, or Glacier Count. 

For Area and Mass, the user can switch between Total Values (Total) or percentage relative to the year 2000 (anomaly). For Glacier count, the user can either see Total Count in 2000 (total), just for 2000, or percent of glaciers remaining since 2000 (anomaly).

Users can select different years using the controls below the map.  

The tooltip displays, for the selected country, values at the country level, subnational level, and—where available—the corresponding pixel (longitude, latitude). The units are the same across.

The map allows users to zoom in or out and toggle between country and pixel views. Selecting the pixel view enables users to click on a specific longitude and latitude for highly localized projections (it’s best to zoom in significantly before selecting). The map selection (country, subnational unit, or pixel) will update the time series shown below.

By default, the map zooms to the selected country and displays the projected glacier mass remaining in 2020 relative to 2000 (%) for SSP5-8.5.

By default, the map shows the proportion of glacier mass remaining at the pixel level in 2020 relative to 2000 under the SSP5-8.5 scenario. Red indicates greater mass loss, yellow represents values close to 100% of the 2000 mass, and blue indicates areas where glacier mass increases, which can occur in some regions during the first half of the 21st century. As you move further into the future using the menu below the map, progressively more mass is projected to be lost. High-emission scenarios show faster glacier decline than low-emission scenarios. You can switch to Total to view total glacier mass instead. Similar visualizations are also available for glacier area and count.

AREA (km²) refers to the total glacier area within the selected pixel, subnational unit, or country. The anomaly (percentage relative to 2000) represents the total glacier area within that spatial unit divided by the total area in 2000, multiplied by 100.

MASS (Mt = megatonnes) refers to the total mass of glaciers within the selected pixel, subnational unit, or country. The anomaly (percentage relative to 2000) is calculated in the same way as for area: the total mass within the spatial unit is aggregated and then expressed as a percentage relative to the total mass in 2000.

ANNUAL MASS CHANGE (Mt/yr) is shown in the time series below. It is calculated as the difference between the median projected glacier mass in consecutive years. Glacier mass loss is closely related to water loss: assuming an ice density of approximately 0.9 kg/m³, annual mass loss can be multiplied by 0.9 to estimate the equivalent volume of water in cubic meters per year (1 cubic meter = 1,000 liters). Key indicators include the year of maximum mass loss and the magnitude of that loss.

GLACIER COUNT (number) refers to the total number of glaciers within a given spatial unit and is shown for the year 2000 only. The anomaly represents the percentage of glaciers remaining relative to the 2000 baseline. It begins at 100% in 2000 and decreases over time as glaciers disappear.

Data from - Rounce, D.R., R. Hock, and F. Maussion. 2022. Global PyGEM-OGGM Glacier Projections with RCP and SSP Scenarios, Version 1. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/P8BN9VO9N5C7

Select area, mass, mass change, or glacier count from the menu to view projected changes from 2000 to 2100 under different scenarios. 

For the selected pixel or political unit (country or subnational), users can view projections of total glacier area, mass, or count as well as percentages relative to the year 2000 (anomaly), across different scenarios. When viewing percentages (for area, mass, and glacier count), dots along the time axis indicate when key thresholds are crossed—75%, 50%, and 25% of the 2000 value, where applicable. Click the right end of the threshold lines to see a summary of threshold crossings.

Note that some scenarios may overlap and obscure others; the legend can be used to add or remove scenarios as needed. 

If a country is selected, users can compare its projections with those of all countries in the same region with the ON/OFF button. If a subnational unit is selected, users can instead compare it with other glacier-active areas (ADM1 regions) within the same country.

Area and Mass.
For area and mass, values are aggregated by summing the area or mass of all glaciers within a region. As a result, these metrics are dominated by the largest glaciers. They are most useful for assessing how much ice (i.e., stored water) exists within a spatial unit and how quickly that total resource is being depleted. When interpreting these indicators, users should pay particular attention to threshold values, such as the point at which total ice cover falls below 50% of its baseline level.

Annual Mass Loss.
For annual mass loss, the key indicators are the timing of peak loss and the magnitude of that loss. Beyond this peak, annual mass loss is expected to decline as glacier mass continues to diminish. These metrics are also largely driven by the largest glaciers within a political unit and are especially relevant for understanding periods of maximum water release and the potential downstream impacts associated with those periods.

Glacier Count.
For glacier count, threshold crossings typically occur earlier. This is because glacier count includes all glaciers regardless of their size or mass, and therefore reflects a distribution that is proportionally more influenced by small glaciers than the area or mass metrics. Since smaller glaciers tend to disappear sooner, thresholds based on glacier count are generally reached earlier.

The summary table displays results across countries within the same region (or subnational units within the selected country) and highlights key milestones, including the percentage of glacier area, mass, and count remaining by 2050 under each scenario, the year in which the 50% threshold is crossed, and, for annual mass loss, the timing and magnitude of maximum loss. 

We have added p10–p90 uncertainty ranges for glacier area, mass, and glacier count. For the projected year of 50% loss, the range is derived from the percentile trajectories: p10 represents the year when the p10 curve (faster loss scenario) crosses the 50% threshold, and p90 represents when the p90 curve (slower loss scenario) crosses the same threshold. If this does not occur before or during 2100, the field is left blank. 

For annual mass change, we do not report p10–p90 ranges because it is non-monotonic, and percentile time series cannot be consistently translated into uncertainty ranges for derived metrics (e.g., extrema or timing), which could lead to misleading interpretations.

When a country is selected on the map above, the user can choose to compare it with other countries within the same region. (When a subnational is selected on map above, the user can choose to compare it with the other subnational units within the same country).

Regions are organized according to geographic proximity and major mountain ranges. Countries spanning multiple regions are assigned to the region containing the majority of their glaciers. The list of regions and countries is ordered by total glacier mass in 2000.

  • Arctic and surrounding regions Canada, Russian Federation, Greenland (Den.), United States of America, Svalbard and Jan Mayen (Nor.), Iceland, Norway, Sweden, ​ Bouvet Island(Nor.)   ​

  • High-mountain Asia  China, Pakistan, India, Tajikistan, Kyrgyz Republic, Nepal, Afghanistan, Kazakhstan, Bhutan, Mongolia​, Uzbekistan, Myanmar

  • Central Europe Switzerland, Italy, France, Austria, Spain, Germany, Albania, Montenegro, Slovenia, Liechenstein ​

  • Southern Hemisphere Maritime Glaciers French Southern and Antarctic Lands(Fr.), Heard Island and McDonald Islands (Aus.), New Zealand, Indonesia ​

  • Latin America Chile, Argentina, Peru, Bolivia, Ecuador, Colombia, Mexico, Venezuela ​

  • Western Asia Georgia, Islamic Republic of Iran, Türkiye, Iraq​

  • Africa  Tanzania, South Africa, Democratic Republic of Congo, Uganda, Kenya​

Data from - Rounce, D.R., R. Hock, and F. Maussion. 2022. Global PyGEM-OGGM Glacier Projections with RCP and SSP Scenarios, Version 1. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/P8BN9VO9N5C7

03 - Projected Global and Regional Glacier Decline

The aim of this section is to provide an at-a-glance view of regional differences—where glaciers are melting more slowly or more rapidly, and where the largest amounts of ice are currently stored.

Select area, mass, mass change, or glacier count from the menu to display a table comparing projected declines globally and across regions. Only the global estimates include a p10–p90 uncertainty range (for area, mass, and glacier count). For all other regions, values are calculated by aggregating each country’s median estimates; p10 and p90 cannot be consistently derived in this way, so these regional values should be considered indicative only.

Regions are organized according to geographic proximity and major mountain ranges. Countries spanning multiple regions are assigned to the region containing the majority of their glaciers. The list of regions and countries is ordered by total glacier mass in 2000.

  • Arctic and surrounding regions Canada, Russian Federation, Greenland (Den.), United States of America, Svalbard and Jan Mayen (Nor.), Iceland, Norway, Sweden, ​ Bouvet Island(Nor.)   ​

  • High-mountain Asia  China, Pakistan, India, Tajikistan, Kyrgyz Republic, Nepal, Afghanistan, Kazakhstan, Bhutan, Mongolia​, Uzbekistan, Myanmar

  • Latin America Chile, Argentina, Peru, Bolivia, Ecuador, Colombia, Mexico, Venezuela ​

  • Southern Hemisphere Maritime Glaciers French Southern and Antarctic Lands(Fr.), Heard Island and McDonald Islands (Aus.), New Zealand, Indonesia ​

  • Central Europe Switzerland, Italy, France, Austria, Spain, Germany, Albania, Montenegro, Slovenia, Liechenstein ​

  • Western Asia Georgia, Islamic Republic of Iran, Türkiye, Iraq​

  • Africa  Tanzania, South Africa, Democratic Republic of Congo, Uganda, Kenya​

Polar and very high mountain regions contain larger glaciers, which are losing mass more slowly in relative (percentage) terms. In contrast, regions dominated by smaller glaciers are projected to experience faster relative losses. The annual mass loss in these regions is expected to increase and reach its peak relatively soon, but at lower absolute values. Regions with larger glaciers are projected to reach their peak mass loss later in the century.

 

Data from - Rounce, D.R., R. Hock, and F. Maussion. 2022. Global PyGEM-OGGM Glacier Projections with RCP and SSP Scenarios, Version 1. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/P8BN9VO9N5C7