Response to Comments on "Saturation of the Southern Ocean CO$_2$ Sink Due to Recent Climate Change"

Corinne Le Quéré (1, 2) , Christian Rödenbeck (3) , Erik T. Buitenhuis (2) , Thomas J. Conway (4) , Ray Langenfelds (5) , Antony Gomez (6) , Casper Labuschagne (6) , Michel Ramonet (7, 8) , Takakiyo Nakazawa (9) , Nicolas Metzl (10) , Nathan P. Gillett (11) , Martin Heimann (3)

1 UEA - University of East Anglia [Norwich]
2 School of Environmental Sciences [Norwich]
3 MPI-BGC - Max-Planck-Institut für Biogeochemie
4 ESRL - NOAA Earth System Research Laboratory
5 CSIRO-MAR - CSIRO Marine and Atmospheric Research
6 SAWS - South African Weather Service
7 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
8 ICOS-RAMCES - ICOS-RAMCES
9 Center for Atmospheric and Oceanic Studies [Sendai]
10 LOCEAN - Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques
11 CRU - Climatic Research Unit [Norwich]

We estimated a weakening of the Southern Ocean carbon dioxide (CO$_2$) sink since 1981 relative to the trend expected from the large increase in atmospheric CO$_2$. We agree with Law et al. that network choice increases the uncertainty of trend estimates but argue that their network of five locations is too small to be reliable. A future reversal of Southern Ocean CO$_2$ saturation as suggested by Zickfeld et al. is possible, but only at high atmospheric CO$_2$ concentrations, and the effect would be temporary.

Domains: Sciences of the Universe [physics]; Ocean, Atmosphere; Sciences of the Universe [physics]; Earth Sciences

Corinne Le Quéré, Christian Rödenbeck, Erik T. Buitenhuis, Thomas J. Conway, Ray Langenfelds, et al.. Response to Comments on "Saturation of the Southern Ocean CO$_2$ Sink Due to Recent Climate Change". Science, 2008, 319 (5863), pp.570c. ⟨10.1126/science.1147315⟩. ⟨cea-00868153⟩