The melting of ice around Antarctica as a result of global warming could be irreversible.

Jeff Ridley and Helene Hewitt of the UK Met Office's Hadley Centre in Exeter used a global climate model to examine how polar sea ice responds to changing climates. They found that Arctic sea ice melts and reforms in response to changing temperatures when carbon dioxide concentrations in the models are first increased and then gradually reduced to pre-industrial levels. In Antarctica, however, sea ice returns at first, but had not recovered by the end of the simulation, even after a further 150 years of pre-industrial CO2 levels.

This lack of ice recovery is a result of strong heat uptake by the Southern Ocean, which continues to warm parts of the seas around Antarctica long after global warming has been reversed, according to the authors.

Geophys. Res. Lett. http://doi.org/xh3 (2014)