Southern Ocean sucks up 1.2bn tonnes of carbon in 2011 and buries it deep

The enormous uptake of greenhouse gases is roughly equivalent to the European Union's annual carbon output

The Southern Ocean has started to absorb more greenhouse gases after a period when the vast ocean's uptake had slumped by about a half, a study has found.

The ocean's role as a crucial carbon "sink" appeared to be waning throughout the 1990s, but after 2002 it began to rebound to its previous level, absorbing 1.2bn tonnes of carbon in 2011.