The Cryosphere
- The cryosphere is all the frozen regions on Earth and covers 13% of the planet's surface
- The term comes from the Greek word 'kryo', meaning cold
- Ice can be found in
- High latitudes - Arctic and Antarctic Circles of more than 65° north and south of the equator
- High altitudes - found in mountain ranges, which can be at any latitude (Drakensberg Mountains, SA is over 3000m high at a latitude of 29° south of the equator)
- Features of the cryosphere include:
- Snow
- Ice (69% of the world's freshwater is stored as ice)
- Permafrost and frozen ground - not all frozen ground is permafrost
- Glaciers
- Ice caps, sheets and shelves
- Icebergs
- Sea, river and lake ice
Parts of the cryosphere
- Most of the cryosphere is found in Antarctica (85%) and the Arctic polar region (12%), as ice sheets, shelf ice, and permafrost
- The largest, single ice mass on Earth is the Antarctic ice sheet, covering 8.3% of the global land surface
- It took millions of years to form; is up to 4.8 km (3 mi) deep in parts; and covers approx. 14 million km² (5.4 million mi²) and contains 30 million km³ of ice
- If it melted, it could raise sea levels by 58 meters (190 feet)
- Permafrost areas are significant global carbon stores and help regulate levels of carbon in the atmosphere
- The cryosphere helps regulate Earth’s climate through its high surface albedo effect
- As the climate warms, the cryosphere also changes through feedback mechanisms, which further influences the climate:
- Increased snow and ice melt, exposes more dark surfaces to insolation
- Which increases surface absorption of solar radiation, causing further melting and release of stored carbon and methane into the atmosphere, which leads to further atmospheric warming
- This is a positive feedback loop, which exacerbates the impacts of climate change