Cryosphere decline beyond a planetary safe operating space, putting conditions for human society at risk

The cryosphere’s frozen landscapes play an irreplaceable role in regulating the Earth’s energy, water, carbon, methane cycles, and carbon storage capabilities. Their breakdown puts communities, ecosystems, and valuable freshwater resources at risk by accelerating global temperature, sea level rise, ecosystem degradation, and the likelihood of catastrophic flooding and drought events – posing a threat to communities across the planet especially in polar, high-mountain, coastal, and low-lying regions.

“The Cryosphere Beyond a Planetary Safe Operating Space” offers an authoritative global assessment of the basic cryospheric conditions required for Earth system resilience – and concludes that these conditions are being transgressed.  Led by researchers at Stockholm Resilience Centre at Stockholm University, it is compiled by an interdisciplinary and international research team of more than 30 scientists, including from the Potsdam Institute for Climate Impact Research (PIK), Tsinghua University, Beijing Normal University, the Earth Commission, the International Association of Cryospheric Sciences (IACS), the Climate and Cryosphere (CliC) Project of the World Climate Research Programme (WCRP), the Third Pole Environment Programme, and the WWF Arctic Programme.

“Only in recent decades have we come to grasp the severity of its ongoing degradation”

“The cryosphere has already exceeded its planetary safe operating space, threatening the frozen foundations of our planet that have supported human civilisations for millennia,” says Bo Su, lead author of the paper and researcher at Stockholm Resilience Centre and Beijing Normal University, and co-chair of the Cryosphere Stewardship Working Group under the IACS. “Compared to other spheres of the Earth system, our systematic understanding of the cryosphere arrived late – only in recent decades have we come to recognise its critical role in maintaining planetary stability, resilience, and habitability, and to grasp the severity of its ongoing degradation. Drawing on the latest advances in cryosphere and Earth system sciences, this work presents a holistic framework for assessing the cryosphere's role in Earth-system resilience.”

The cryosphere’s “safe operating space” (“SOS”), a framework outlined in the paper, defines precautionary boundaries for the planet’s frozen areas, the absence of which has limited policymakers’ ability to understand and govern cryosphere stability to date. The boundaries are defined using conditions over the past 11,700 years, an epoch known as the Holocene, as their reference point. This period was characterised by relatively stable global environmental and climate conditions that allowed human civilisations to develop and thrive. Moving beyond these conditions takes humanity into uncharted territory.

Risks associated with the cryosphere decline are already visible today

The study concludes that the cryosphere has moved beyond its safe operating space, as current and committed changes are taking it increasingly far from the relatively stable conditions of the past 11,700 years. These changes also risk triggering reinforcing feedback loops that accelerate further cryosphere degradation and make return to those conditions increasingly difficult.

The degradation of frozen landscapes is driven predominantly by human-induced climate change, in addition to regional human disturbances including black carbon emissions and industrial and infrastructure expansion. The authors therefore urge policymakers to use the proposed SOS as a scientific basis for developing precautionary targets and strategies to limit greenhouse gas, black carbon emissions, and reduce local human disturbances.

“This work substantially furthers our understanding of how cryosphere changes are threatening the stability and resilience of life-supporting conditions of the Earth system,” says PIK director Johan Rockström, Co-Chair of the Earth Commission and author of the study. “As cryosphere risks unfold before our eyes – most recently with the floods in Nepal – the report’s arrival at COP31 issues an important reminder for global leaders of the significance of cryosphere governance.”

The study outlines different options for integrating the cryosphere’s safe operating space into the planetary boundaries framework, in order to better understand and address the mounting risks.

“This timely, integrated update on the state of cryosphere decline, its impact on the Earth’s environment and the impacts on humanity’s prosperity and survival issues a clear warning on the emergency of cryosphere collapse that global policymakers must heed at COP31 and beyond,” adds John Pomeroy, Chair, Strategic Management Committee for the UN Decade of Action for Cryospheric Sciences, UNESCO Chair in Mountain Water Sustainability, and distinguished professor at the University of Saskatchewan. “The paper makes an important contribution to delivering on the ambitions of the UN Decade of Action for Cryospheric Sciences (2025-2034), while reinforcing the need for coordinated international action on preserving our cryosphere, and the irreplaceable freshwater, ocean and ecosystem services it provides.”

The report arrives amid the UN Decade of Action for Cryospheric Sciences (2025–2034) and COP31 in Antalya, Türkiye (November 9-20), offering a comprehensive scientific springboard for unprecedented opportunities for coordinated international action.