Peak glacier extinction in the mid-twenty-first century

Using three global glacier models applied to the ~215,543 glaciers in the RGI v6.0 inventory, the study introduces “peak glacier extinction” and projects a mid‑21st century spike in glacier disappearances from today’s modeled ~750–800 per year to ~2,000/year under +1.5 °C (peak ~2041) and up to ~4,000/year under +4.0 °C (peak mid‑2050s)—a rate at peak equivalent to losing the entire European Alps glacier population in a single year. Timing and magnitude vary regionally: small, fast‑responding glacier regions (Alps, Caucasus, Subtropical Andes, North Asia) will see rapid, early losses (often >50% within two decades), while regions dominated by larger glaciers (Greenland/Antarctic peripheries, Svalbard, Russian Arctic, parts of High‑Mountain Asia with ~90,000 glaciers) peak later; by 2100 projected survivors fall from roughly 50% under +1.5 °C to ~20% under +2.7 °C and below 10% under +4.0 °C. The results — based on GloGEM, OGGM and PyGEM simulations and conservative disappearance thresholds (area <0.01 km2 or volume <1% of initial) but subject to inventory and fragmentation uncertainties — signal material risks to water resources, tourism and cultural heritage and imply that near‑term mitigation and targeted adaptation can substantially alter the scale and timing of losses.

Analysis

The study analyzes 215,543 glaciers from RGI v6.0 using three global glacier models (GloGEM, OGGM, PyGEM) and defines "peak glacier extinction" as the year with the largest number of individual glacier disappearances. Modelled present-day loss is ~750–800 glaciers per year; under a +1.5 °C pathway peak extinction reaches ~2,000 glaciers/year around 2041, while a +4.0 °C pathway delays and amplifies the peak to ~4,000/year in the mid-2050s. By 2100 projected survivors range from roughly 50% under +1.5 °C to ~20% under +2.7 °C and below 10% under +4.0 °C.

Regional outcomes diverge sharply: High‑Mountain Asia contains ~90,000 glaciers (~one third of the inventory) and drives the global mid‑century signal, small‑glacier regions (European Alps, Caucasus, Subtropical Andes, North Asia) may lose >50% within two decades, and Central Asia’s loss could rise from 200–300/year today to ~500/year under +1.5 °C and ~1,100/year under +4.0 °C. These shifts reduce glacier area and reweight size distributions toward very small ice bodies, with attendant impacts on meltwater supply and tourism.

The analysis emphasizes material consequences for water resources, ski and glacier tourism revenues, and cultural heritage, and shows mitigation choices materially alter long‑term glacier counts. Results are subject to inventory completeness, the RGI v6.0 baseline, the 0.01 km2/1% volume disappearance thresholds, and the fact that fragmentation and some very small glaciers are not fully represented, increasing regional uncertainty.

Key Decisions for Investors

• Reassess and where appropriate reduce unhedged exposure to operators dependent on glacier tourism and summer/winter recreation in highly vulnerable regions (Alps, Western Canada/USA, Low Latitudes), given the prospect of rapid near‑term glacier loss
• Stress‑test portfolio holdings in water‑intensive sectors (utilities, hydropower, agriculture) for regional meltwater reductions, prioritizing positions in High‑Mountain Asia, Central Asia and the Andes where glacier retreat will materially affect seasonal runoff
• Increase allocation to adaptation and resilience opportunities—water storage and distribution, desalination, climate‑resilient infrastructure, and insurance/catastrophe‑risk transfer providers—that can benefit from rising demand as glaciers decline
• Integrate explicit climate pathways (+1.5 °C, +2.7 °C, +4.0 °C) into valuation and scenario analyses because near‑term policy choices materially change the scale and timing of glacier loss and attendant economic impacts
• Monitor updates to glacier inventories (RGI v7.0), model improvements (fragmentation/3D modelling) and observational indicators through 2025 as triggers to reprice regional exposures and adjust hedges