environment – From a Glaciers Perspective

**Global alpine mass balance in 2024 as reported to the World Glacier Monitoring Service. Solid line is the cumulative balance, bars are the annual balance.**

Each of the last 15 years I have summarized the annual mass balance of alpine glaciers globally for the Bulletin American Meterological Society-State of the Climate report,. Below is the 2024 section on alpine glaciers with a few added figures.

ALPINE GLACIERS
M. Pelto

In 2024, all 58 global reference glaciers reported a negative annual mass balance. This is only the second year in the 1970–2024 period with all negative annual balances, following 2023. The global average annual mass balance based on equal weighting of 19 regions is −1.30 m water equivalent (w.e.), the most negative value in the record

The 2024 dataset of submitted glaciological observations includes 142 glaciers from six continents and 27 nations, with 140 reporting a negative balance and 2 a positive balance. In 2024, the mean annual mass balance of the 58 global reference glaciers was −1.44 m w.e. and −1.36 m w.e. for all 142 reporting glaciers. This is a similar result to 2023, which saw a mean reference glacier balance of −1.62 m w.e. and −1.35 m w.e. for all 116 reporting glaciers.

The 2024 regionalized global average of −1.30 m w.e. exceeds the previous most negative year in 2023, which saw a regional-ized global average of −1.25 m w.e. This makes 2024 the 37th consecutive year with a global alpine mass balance loss and the 15th con-secutive year with a regionalized global mass balance below −0.5 m w.e. The acceleration of mass balance loss indicates that alpine glaciers are not approaching equilibrium. The acceleration of mass balance loss is apparent regardless of datasets used to determine it, including glaciological, geodetic, altimetry, and gravimetric observations (The GlaMBIE Team 2025). The intercomparison assessment identified that global glaciers annually lost 273+26 gigatons (Gt) in mass from 2000 to 2023, with loss having been 36% greater in the second half than in the first half of this period (The GlaMBIE Team 2025).

In the European Alps, all 49 glaciers reported negative mass balances, with 45 losing over 1 m w.e. All 10 Icelandic glaciers had negative balances. In Svalbard, all seven had negative balances exceeding an exceptional loss of 1.25 m w.e. This was the result of near complete snow cover loss across most glaciers (Fig. 2.20) following record temperatures in August (see section 7f5 for details). Twelve of the 13 glaciers from Norway and Sweden had mass losses of more than 1.0 m w.e.

**High snow line persisted through the winter on Mount Everest glaciers.**

Across High Mountain Asia, 20 of 21 glaciers, reporting from seven nations, had negative balances. The highest average losses were in the Himalayas of Nepal and the lowest in the Pamir Range of Tajikistan.

In the Andes Mountains of South America, all 14 glaciers, reporting from five nations, had negative balances. Conejeras Glacier (Colombia), following a 5.04 m w.e. loss in 2023, was declared extinct in 2024. The daily hydrograph below this glacier changed from a predominanceof days with a purely melt-driven hydrograph from 2006 to 2016 to an increase in the frequency of days with flows less influenced by melt after 2016 (Morán-Tejeda et al. 2018).

All 16 glaciers in North America had negative balances. All four glaciers in Arctic Canada had mass balance losses under 1 m w.e. In western Canada and Washington and Montana (United States), all 16 glaciers reporting had losses exceeding 1 m w.e. The Ice Worm Glacier (Washington) was listed as extinct in 2023 after 40 years of continuous observations (Pelto 2024). In 2024, loss from the relict ice (ice that is no longer moving or part of a glacier) was 2.4 m and melt runoff below the glacier had decreased similar to Conejeras Glacier (Pelto and Pelto 2025). In Alaska, all three glaciers had mass balance losses. Davies et al. (2024) examined the Juneau Icefield, the most observed icefield in Alaska in terms of mass balance, and found an acceleration of mass loss with a doubling after 2010 compared to 1979–2010.

**Easton Glacier, Washington extensive retreat since 1990, with last five years being the most rapid. Terminus and mass balance surveyed annually and reported to WGMS.**

Alpine annual mass balance glaciological observations are reported to the World Glacier Monitoring Service (WGMS) by national representatives with a 1 December annual submission deadline. WGMS reference glaciers have at least 30 continuous years of mass balance observa-tion. Benchmark glaciers have at least a 10-year mass balance record and are in regions that lack sufficient reference glaciers. The combination of benchmark and reference glaciers is used to generate regional averages (WGMS 2023). Global values are calculated using a single averaged value for each of 19 mountain regions, limiting bias from observed regions (WGMS 2023). As this dataset expands, the annual values are reanalyzed and updated.

The lack of snow pack at the end of summer is evident across Edgeoya in Svalbard, blow a closeup of Digerfonna further illustrates with lettered points indicating new bedrock areas that are expanding amidst the ice cap.

March 21, 2026 was World Day for Glaciers, telling this story is an ongoing four decades long project for us. The North Cascade Glacier Climate Project began in 1984 to identify the response of Washington’s North Cascade glaciers to climate change. The 2026 field season will mark our 43^rd year of observations.

I co-direct the project as the science director, with Jill Pelto as the art director. We strive to create a diverse and collaborative portfolio of impactful observations connecting people to science through art and data publication. Our theory of change is that art has the power to inspire people by including the emotional context behind the science research. We seek collaborators who are passionate about contributing to and sharing this work. Here we reflect on some of the stories we have shared in the last 12 months that chronicle the rapidly melting reality of glaciers.

In April, 2025 the “Shaped by Ice” exhibit coordinated by Jill Pelto opened at the Slip Gallery in Seattle. This featured work from nine artists, eight of whom had been in the field with us and was the focus of a Seattle Magazine article.

In May we worked with Protect Our Winters to explore what the loss of glaciers, “Beyond the Ice” means for specific regions.

In June, High Country News focused on the use of art to preserve the legacy of glaciers, given the glaciers themselves are not being preserved.

In March through July we worked with the Global Glacier Casualty List to the tell the story of specific glaciers in the United States that are disappearing, including Ice Worm Glacier in the North Cascades, Darwin Glacier in the Sierra Nevada, Twins Glacier in Wyoming and Burroughs Glacier in Alaska.

In August our field season coincided with a Seattle Time report, on Melting Mountains in the Pacific Northwest means, that we collaborated on.

Joining us in the field on the Lower Curtis Glacier, Mount Shuksan was KING5 NBC-Seattle affiliate, led by Meteorologist Leah Pezzetti who backpacked with us into her first glacier. The logistical preparation for this by KING5 was thorough, and we provided guidance and support to them. The resulting feature was released while we were still in the field.

Upon returning to the trailhead from Lower Curtis Glacier a CBS Sunday Morning News team met us and travelled into the field with us to Sholes Glacier, Mount Baker. The overnight trip into the backcountry was a first for this news team and required extensive collaborative support. The results were shared just two weeks after the filming, and right after our field season.

We worked for a second year with Dan MacComb on a short film for the UN International Year of Glaciers’ Preservation called “Shaped by Ice”. This film published by Protect our Winters has been featured in tfour film festivals during 2025.

In January through February a second “Shaped by Ice” gallery event was held in at the Confluence Gallery in Twisp WA. This was spearheaded by Jill Pelto, Margaret Kingston, and Claire Waichler.

A poor winter snowpack will certainly lead to another year of extensive glacier loss across the Pacific Northwest and we will be there to observe it.