The Cryosphere

Climate change is happening in the cryosphere faster and more dramatically than anywhere else on earth.

The word “cryosphere” comes from the Ancient Greek root krúos meaning “very cold, freezing” and sphaîra for “globe”. The cryosphere is a term for the regions of our globe which are covered in ice and snow either seasonally or year-round. Ice sheets, sea ice, glaciers and snow, and permafrost play a crucial role in our cryosphere. Together, these regions cover more than 15% of Earth’s surface. They are clear indicators of climate change, and ice loss from these regions brings increased risk to ecosystems and human communities on a global scale. Already by the 1990s, it had become abundantly clear that rising temperatures from CO2 emissions are causing portions of the cryosphere (especially mountain glaciers and Arctic sea ice) to shrink dramatically.

Decades of research findings offer a clear and vital message: the cryosphere no longer is just “the canary in the coal mine,” or an early indicator of climate change. Instead, as the cryosphere deteriorates across the globe, the impacts are reaching into parts of the globe far from the cryosphere itself. Melting glaciers and ice sheets add to sea-level rise; thawing permafrost already pours carbon emissions into the atmosphere on the same scale as a major country; acidifying polar oceans absorb carbon from the air and dissolve the shells of marine organisms; vanishing Arctic sea ice increases global warming and strengthens extreme weather events across Eurasia and North America; disappearing mountain glaciers and snowpack decrease water supplies for agriculture, power generation and tourism. The Fact Sheets below contain more detail on each of these cryosphere dynamics.

Every fraction of a degree matters.

These impacts from our planet’s loss of its natural ice regions will grow ever more catastrophic with each fraction of a degree of temperature rise, especially if we exceed the Paris Agreement limit of 1.5°C, and even more so above 2°C.

Nearly all of the changes caused by cryosphere loss are essentially permanent, lasting many centuries or thousands of years. The level of damage is going to be set by peak temperature: even a later return to lower temperatures (unless we induce an Ice Age) will not bring most of this ice back. Cryosphere scientists are largely in agreement that even 2°C is too high – we can see in Earth’s past a planet with sea levels 15-25 meters higher than today at that temperature. Physical observations, paleo-record reconstructions, modeling projections and beyond confirm that even 1.5°C is too costly over long periods of time. Instead, we need to see 1.5°C as a guardrail, a level which we should not exceed or exceed only briefly, and even then work to come down below 1°C as soon as possible.

A message of urgency and hope.

The cryosphere is on an accelerated warming path, and some of those changes may drive global climate change faster and further than we are currently prepared to handle. If warming continues unabated, the risks from continuing sea-level rise, flooding, and water resource disruption rise dramatically. So too will the risk of large CO<sub>2</sub> and methane releases from permafrost, potentially eclipsing global efforts to reduce carbon pollution. The window to slow some of these processes may be closing rapidly.

These simple geophysical realities are entirely driven by the melting point of water. By lowering our CO2 emissions primarily from our use of fossil fuels, we can still act in time to curb global temperature rise and limit the loss of these vulnerable snow and ice regions, thereby protecting global health and well-being for generations.

For greater detail, see the State of the Cryosphere 2022 report, written and reviewed by more than 60 leading cryosphere scientists and IPCC authors, released at COP27 in Sharm El Sheikh, Egypt; and the Thresholds and Closing Windows Report, released in conjunction with the 2016 Paris Agreement.

Cryosphere Fact Sheets: English (Swedish versions below)

Click the images below for key facts on some of the most important components of the cryosphere:

Antarctic Ice Sheet

Greenland Ice Sheet

Arctic Sea Ice

Mountain Glaciers and Snow


Polar Oceans

Cryosphere and the 1.5°C limit

Cryosphere Fact Sheets: på svenska

Få viktiga fakta om några av de viktigaste komponenterna i kryosfären genom att klicka på bilderna nedan:

Den Antarktiska inlandsisen


Arktis Havsis



Polära Haven

Vägar till 1.5°C