NIWA biological oceanographer Dr Philip Boyd explains how the Southern Ocean plays a key role in controlling the world's climate, by drawing large amounts of CO2 from Earth's atmosphere into the ocean depths.
He outlines three factors that may determine the Ocean's influence on atmospheric CO2: the supply of iron to phytoplankton (which form a 'biological pump' for CO2), sea ice, and ocean circulation. These factors offer compelling explanations for the Ocean being less of a carbon sink now than it was in the distant past.