Saturation of the Southern Ocean CO2 Sink Due to Recent Climate Change
- Corinne Le Quéré1,2,3,*,
- Christian Rödenbeck1,
- Erik T. Buitenhuis1,2,
- Thomas J. Conway4,
- Ray Langenfelds5,
- Antony Gomez6,
- Casper Labuschagne7,
- Michel Ramonet8,
- Takakiyo Nakazawa9,
- Nicolas Metzl10,
- Nathan Gillett11,
- Martin Heimann1
- 1 Max Planck Institut für Biogeochemie, Postfach 100164, D-07701 Jena, Germany.
- 2 School of Environmental Sciences University of East Anglia, Norwich NR4 7TJ, UK.
- 3 British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK.
- 4 National Oceanic and Atmospheric Administration, Earth System Research Laboratory, 325 Broadway, Boulder, CO 80305, USA.
- 5 Commonwealth Scientific and Industrial Research Organisation, Marine and Atmospheric Research, PMB1 Aspendale, Victoria 3195, Australia.
- 6 National Institute for Water and Atmospheric Research, P.O. Box 14901, Wellington, New Zealand.
- 7 South African Weather Service, P.O. Box 320, Stellenbosch, 7599 South Africa.
- 8 Laboratoire des Sciences du Climat et de l'Environnement/Institut Pierre Simon Laplace (LSCE/IPSL), Gif-sur-Yvettes, Cedex 91191, France.
- 9 Center for Atmospheric and Oceanic Studies, Tohoku University, Sendai 980-8578, Japan.
- 10 Laboratoire d'Océanographie et du Climat: Experimentation et Approaches Numériques (LOCEAN/IPSL) CNRS, Université Pierre and Marie Curie, Paris, France.
- 11 Climate Research Unit, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
- ↵* To whom correspondence should be addressed. E-mail: c.lequere{at}uea.ac.uk
Abstract
Based on observed atmospheric carbon dioxide (CO2) concentration and an inverse method, we estimate that the Southern Ocean sink of CO2 has weakened between 1981 and 2004 by 0.08 petagrams of carbon per year per decade relative to the trend expected from the large increase in atmospheric CO2. We attribute this weakening to the observed increase in Southern Ocean winds resulting from human activities, which is projected to continue in the future. Consequences include a reduction of the efficiency of the Southern Ocean sink of CO2 in the short term (about 25 years) and possibly a higher level of stabilization of atmospheric CO2 on a multicentury time scale.
- Received for publication 11 October 2006.
- Accepted for publication 2 May 2007.
