New research has shed light on the threat posed by climate change to Antarctica. Parts of the continent are surrounded by vast areas of sea ice, which play a crucial role in its climate. A number of these ice shelves are in danger of collapsing by 2100. Some have already been damaged – large sections of the Larsen B shelf broke up in 2002. This shelf, which was 12000 years old, is expected to vanish completely with 5 years. Many other shelves have thinned significantly.
There are two main routes of melting: destruction from below by seawater, which has the biggest impact, and surface melting. A fresh study has drawn attention to the implications of surface melting on the especially vulnerable Antarctic Peninsula. This area is where Larsen B is found. The melting was analysed by satellite imaging, linking the current state of the peninsula to the summer air temperature. Another link was found with carbon dioxide levels.
If the ice shelves vanish, many Antarctic glaciers and other fresh-water sources will empty directly into the ocean. They would then flow much faster, making the continent lose fresh water more rapidly. Sea levels would rise. Dr Luke Trusel, the lead researcher of the project, said “Our results illustrate just how rapidly melting in Antarctica can intensify in a warming climate.”
The scientists also modelled likely events in a high-emission and a lower-emission future. The situation is not yet out of control: Antarctica’s ice could be stabilised within decades if emissions don’t stay on their current path. However, the shelves are currently very much at risk.