Measuring the changes in the ocean’s capacity to absorb CO2


Concentrations of CO2 in the atmosphere have increased since 1750 AD as a result of human activity. This is linked to warming of the atmosphere and oceans, changes in climate, recession of ice sheets and sea level rise. More than one quarter of this CO2 is absorbed by the oceans; the Southern Ocean accounting for 43%. The capacity of the Southern Ocean to absorb CO2 has recently been limited (according to some models) by an increase in the strength of the Southern Hemisphere Westerly Winds (SHW), which draw CO2 saturated waters back to the surface. This will potentially drive up atmospheric greenhouse gases and accelerate rates of global warming.

Thus reconstructing past changes in the SHW and their impact on the oceanic CO2 sink is now a major priority for palaeoclimate science. Our objectives are to:

A. determine the Holocene (last 12000 yrs) changes in the strength of the SHW over the Southern Ocean by generating records of wind-driven aerosols and other proxies in sediment records from lakes and bogs on the west coasts of sub-Antarctic islands and,

B. use these data in global climate models to test if past changes in the SHW explain past variations in atmospheric CO2.

Principal Investigator (PI)

Dominic A. Hodgson

British Antarctic Survey, UK


Southern Ocean westerly winds and the global CO2 sink

Principal institution / country

  • British Antarctic Survey (UK)
  • Universities of Exeter and Cambridge (UK
  • Oeschger Centre, University of Bern (CH)
  • ANSTO: Australian Institute of Nuclear Science and Engineering (Australia)
  • Dept. Biology, University of Ghent (Belgium)
  • Lab. Ecologie Fonctionnelle et Environ. (CNRS) Universtity of Toulouse (France)
  • Earth and Environmental Sciences,
  • Lehigh University (USA)
  • Quaternary Science,
  • Lund University (Sweden)