In the high-altitude regions of Switzerland, the Morteratsch-Pers glacier complex is witnessing a dramatic retreat, a sign of the profound and lasting consequences of global climate change. Newly formed in 2023, an ice cave within this glacier complex serves as a striking marker—a glacier gate where meltwater emerges—a visual testament to the accelerating loss of ancient ice masses. This phenomenon is not isolated; it reflects a global pattern of glacier degradation, where snow and ice reserves that once seemed eternal are now increasingly vulnerable. Recent research spearheaded by a multinational team including scientists from ETH Zurich underscores the scale and persistence of this crisis, revealing that the future of glacier preservation hinges critically on the global community’s climate actions today.
The research, published in the esteemed journal Science, provides an unprecedented multi-centennial analysis of glacier mass evolution across more than 200,000 glaciers worldwide, excluding Greenland and Antarctica. Using a suite of eight independent glacier models, the team evaluated a comprehensive range of global temperature stabilization scenarios stretching well beyond the year 2100. Unlike prior studies confined to the turn of the century, this broader timeline exposes the prolonged and inevitable long-term responses of glacier systems to present and future warming trajectories. In every scenario examined, glaciers continue to shrink for centuries after initial temperature spikes, underscoring the persistence of climate impacts embedded in today’s atmospheric conditions.
Central to the study is the stark projection that stabilizing global temperatures at current levels—approximately 1.2°C above pre-industrial baselines—will still result in nearly 40 percent loss of global glacier ice mass relative to 2020. This apocalyptic forecast translates to an eventual contribution of over 10 centimeters to global sea-level rise, emphasizing the enduring legacy of thermal inertia within glacier systems. Such melting not only elevates sea levels but exacerbates risks of flooding, destabilizes mountain ecosystems, and threatens vital freshwater supplies, especially in regions reliant on glacier-fed rivers. The long-term retreat of glaciers also imperils the economies and cultures intertwined with regional glaciers, from Alpine tourism to indigenous communities.
One of the most innovative aspects of this work is its time scale: by projecting glacier responses over several centuries to millennia, the researchers capture the slow adjustment processes of ice masses as they evolve towards new equilibrium states at higher elevations. This is a critical departure from most current climate models, which typically limit projections to the year 2100 and thus underestimate the ultimate glacier loss. The extended timescale reveals that while glacier mass declines rapidly in the near term under warming, the melt continues at a measured but persistent pace long after temperatures stabilize, driven by thermal and dynamic feedback mechanisms intrinsic to glacier physics.
The collaborative study was led by Dr. Harry Zekollari from Vrije Universiteit Brussel and ETH Zurich, alongside co-lead author Lilian Schuster from the University of Innsbruck. Together with nineteen other scientists from ten countries, they merged expertise in glaciology, climate modeling, and computational simulations to deepen the understanding of how differing levels of warming impact glacier futures. The team’s integration of multiple glacier models enhances the robustness of their findings, mitigating the uncertainties inherent in using any single model. This methodological rigor lends new weight to the conclusion that nearly half of the planet’s glaciers are effectively "doomed" to disappear, based on current warming trajectories.
Importantly, the study highlights the critical importance of limiting warming to lower thresholds. Where global temperatures rise by 2.7°C—a scenario consistent with current climate policies—the projected glacier loss practically doubles compared to a more ambitious stabilization target of 1.5°C. Every fraction of a degree matters: for each 0.1°C increase in warming, the world risks losing an additional two percent of glacier ice. This nuanced understanding of glacier sensitivity offers vital evidence for policymakers aiming to balance economic progress with environmental preservation without underestimating glacial vulnerabilities.
Glaciers serve as sentinel indicators of climate change, providing tangible, observable evidence of shifts in atmospheric and environmental conditions over time. However, the very nature of glaciers—slow to respond yet persistent in adjustment—means their visible retreat drastically lags behind the actual scale of warming already baked into the climate system. As Schuster notes, the current sizes of glaciers grossly underestimate the magnitude of warming that has occurred, meaning the full consequences are yet to be manifested. This introduces a sobering dimension to climate discussions: even if carbon emissions cease immediately, the glacier losses will continue for centuries due to delayed responses.
Beyond the scientific revelations, the study’s timing and influence are amplified by their alignment with global policy initiatives. It was published to coincide with the opening of the High-Level International Conference on Glaciers’ Preservation in Dushanbe, an event launched under the aegis of the United Nations and the Government of Tajikistan. The conference marks the UN International Year of Glaciers’ Preservation, underscoring a global call to action for cryosphere protection. ETH Zurich’s Professor Daniel Farinotti, who played a pivotal role in these studies, also serves as an advisor to Switzerland’s Federal Department of Foreign Affairs in drafting the forthcoming "Dushanbe Glacier Declaration," aimed at galvanizing international commitments towards glacier conservation.
Technically, the study employs advanced computational simulations to model glacier mass balance dynamics over extensive timescales. By leveraging the Glacier Model Intercomparison Project (GlacierMIP) framework, coordinated by the Climate and Cryosphere (CliC) Project of the World Climate Research Programme, the research taps into a collaborative and standardized approach to simulating cryospheric changes. This comprehensive modeling enables the disentanglement of complex physical processes such as accumulation and ablation, ice flow, and climate-glacier feedbacks, providing a far more precise and detailed picture of glacier futures than was previously achievable.
The implications of these findings traverse environmental science into socio-economic domains. Glacier melting threatens freshwater availability for millions, particularly in arid regions dependent on meltwater during dry seasons. The destabilization of glacier-fed landscapes increases hazards such as floods, landslides, and glacial lake outburst floods (GLOFs), with direct consequences for human safety and infrastructure. Tourism economies rooted in mountain and glacier-based experiences are also poised for disruption, with regional identities and livelihoods at risk. This cascade of effects highlights the interconnectivity of cryospheric health and broader planetary and societal systems.
In synthesizing these outcomes, the research team underscores the urgency for decisive and immediate climate action. Every incremental reduction in greenhouse gas emissions can yield substantial benefits for glacier preservation and, by extension, for sea-level stability, ecosystem integrity, and human well-being globally. Given the entrenched and slowly unfolding nature of glacier responses, policies enacted today will reverberate across centuries, making current decisions a defining legacy for future generations. The study’s compelling data should serve as a clarion call to nations, industries, and civil society alike to intensify efforts toward ambitious climate targets before irreversible threshold losses occur.
The Morteratsch Glacier’s newly formed ice cave, gleaming faintly in the Swiss Alps, epitomizes a world in flux—where natural wonders once seemingly eternal are now under existential threat. This symbolic gateway of meltwater emergence invites a deeper reckoning with humanity’s role in shaping Earth’s climatic future. The hope lies in the demonstrated power of limiting warming—doubling glacier preservation at the difference between 1.5°C and 2.7°C—and the collective will to translate scientific insight into transformative climate action.
Subject of Research: Not applicable
Article Title: Glacier preservation doubled by limiting warming to 1.5°C versus 2.7°C
News Publication Date: 29 May 2025
Web References: http://dx.doi.org/10.1126/science.adu4675
References: Zekollari, H, Schuster, L et al. Glacier preservation doubled by limiting warming to 1.5°C versus 2.7°C. In: Science, 29 May 2025. DOI:10.1126/science.adu4675
Image Credits: Lander Van Tricht / ETH Zurich and Vrije Universiteit Brussel
Keywords: Glacier loss, global warming, climate change, glacier modeling, sea-level rise, cryosphere, multi-centennial projections, glacier preservation, climate policy, computational simulation
