This symposium was delayed from 2021 and will bring together scientists and policy makers for a discussion on the latest results from studies of the entire cryosphere, which plays an important role in the hydrological cycle and the Earth System and is one of the most useful indicators of climate change. The symposium will allow ample time for panel discussions on scientific results, new technologies, research gaps and future perspectives in the light of the Paris Agreement that calls for limiting global warming to 1.5–2°C.

Sessions will cover the following topics:

1. Earth’s snow cover: Snow science, recent snow cover changes in mountain and polar regions; satellite monitoring of snow cover; GPR measurements of snow thickness; importance of snow cover for tourism; avalanche hazard mitigation.
2. The cryosphere and hydrology: Importance of snow and ice melt as a water resource for mountain region populations and for hydropower utilization; runoff changes due to atmospheric warming; monitoring of changes in lake and river ice.
3. Permafrost: Nature and distribution; ongoing changes; impacts on the hydrological cycle; monitoring challenges; increased risks of landslides due to permafrost thawing; adaption implications for populations.
4. Ocean–cryosphere interactions: Transfer of water between the oceans and snow and ice masses on land; changes in ocean heat content; effects of declining Arctic sea-ice cover on the climate system; effects of oceanic warming on tidewater glaciers; potential changes in deepwater formation in the North Atlantic ocean; tipping points in the ocean–cryosphere system.
5. Glaciers and ice caps: Historical changes in glacier area and mass balance all over the world; mass-balance measurements and modelling; glacier dynamics and evolution; melt processes and glaciohydrology; glacier outburst floods (jökulhlaups); glaciers in high-mountain areas and impacts of their melting on populations; future perspectives on glacially fed rivers as water resources.
6. The Greenland Ice Sheet: Age and history; deep ice-core records; internal structure; recent changes; likely response to near-future warming; varying contribution of Greenland mass loss to sea level in different parts of the world’s oceans; research on surface melt lakes and runoff; ice velocity studies.
7. The Antarctic Ice Sheet: History; internal structure; key data from ice cores on past atmospheric composition; vulnerability of the West Antarctic Ice Sheet to rising sea level; research on subglacial water systems; Antarctica in the climate system.
8. Sea ice: Nature and distribution; changes in area, thickness and volume; past variations; likely changes during the 21st century; importance of sea ice in the Earth's climate system; ongoing developments in the Arctic (e.g. shipping, settlements, research coverage).
9. Climate variations, climate- and Earth-system modelling: Representation of the cryosphere in climate models and Earth systems models; modelling of cryospheric variations and resulting hydrological changes on all time scales from ice ages through Holocene climate variations to centennial, decadal and annual variations; importance of the cryosphere as a trigger of rapid climate change.
10. Research gaps, monitoring programmes, new technologies: Emerging methods and technologies in surface-based, airborne and spaceborne studies of snow, glaciers and ice sheets, lake and river ice conditions and permafrost, with special emphasis on the development of derived products for cryospheric and polar scientific research and applications.
11. Opportunities, adaptation and mitigation: Importance of evaluating and estimating current and future cryospheric variations for the design and operation of societal infrastructure, such as coastal and hydrological infrastructure and hydropower systems.
12. Humans and the cryosphere: navigating complex change in the Anthropocene. Adaptation of human beings to cryospheric environments through time, challenges to indigeneous communities presented by increasingly rapid environmental and social change.

For more information, please visit the Symposium website.