The “cryosphere” simply means “ice globe”: all the portions of the planet with some form of frozen water, currently around 15% of Earth’s surface: ice sheets, glaciers and snow; permafrost, or frozen ground; sea ice and ice shelves; and in the ICCI context, we also term the two great polar oceans (the Arctic Ocean and Southern Ocean) as “cryosphere”. Already in the 1980’s, it was clear these regions were changing and warming. By the 1990’s, it was clear that increasing temperatures from CO2 emissions – climate change – was causing portions of the cryosphere (especially land glaciers and Arctic sea ice) to shrink dramatically.
The International Polar Year of 2007-08 did much to spearhead new research and human knowledge of climate impacts in these regions, with the participation of thousands of scientists across many disciplines (see www.ipy.org). Today in 2022, this new research has matured into a clear and vital message from the cryosphere science community: the cryosphere no longer is just “the canary in the coal mine,” i.e. 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 pours carbon emissions into the atmosphere on the same scale as today’s Japan; polar oceans are acidifying rapidly as these absorb our excess CO2 emissions; lost Arctic sea ice accelerates global warming, and may be driving extreme weather events across Eurasia and North America; lost snowpack and glacier ice negatively decreases water supplies for agriculture, power generation and tourism. The Fact Sheets below contain more detail on each of these cryosphere dynamics.
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, should we exceed the Paris Agreement limit of 1.5°C, and even more so above 2°C. Perhaps more importantly: these changes caused by cryosphere loss are nearly all essentially permanent, lasting many centuries or thousands of years. And 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. Today, virtually all cryosphere scientists agree that even a 2°C is too high – we can see in Earth’s past a planet with 15-25m higher sea levels than today at that temperature. The science indeed says 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 working to come down below 1°C as soon as possible.
These are simple geo-physical realities: driven entirely by the melting point of water. But we can still act in time, by lowering our CO2 emissions, primarily from our use of fossil fuels. For greater detail, see the State of the Cryosphere Report 2021, written and reviewed by over 50 leading IPCC and other cryosphere scientists, released at COP-26 in Glasgow; and Thresholds and Closing Windows, released in conjunction with the 2015 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:
Cryosphere Fact Sheets: på svenska
Få viktiga fakta om några av de viktigaste komponenterna i kryosfären genom att klicka på bilderna nedan: