Decadal trends in the ocean carbon sink
|Author(s)||Devries Tim1, 2, Le Quere Corinne3, Andrews Oliver3, 4, Berthet Sarah5, Hauck Judith6, Ilyina Tatiana7, Landschuetzer Peter7, Lenton Andrew8, 9, 10, Lima Ivan D.11, Nowicki Michael1, 2, Schwinger Jorg12, Seferian Roland5|
|Affiliation(s)||1 : Univ Calif Santa Barbara, Dept Geog, Santa Barbara, CA 93106, USA.
2 : Univ Calif Santa Barbara, Earth Res Inst, Santa Barbara, CA 93106 ,USA.
3 : Univ East Anglia, Sch Environm Sci, Tyndall Ctr Climate Change Res, Norwich NR4 7TJ, Norfolk, England.
4 : Univ Bristol, Sch Geog Sci, Bristol BS8 1TH, Avon, England.
5 : Ctr Natl Rech Meteorol, Unite Mixte Rech, F-31100 Toulouse, France.
6 : Alfred Wegener Inst, Helmholtz Zentrum Polar & Meeresforsch, D-27570 Bremerhaven, Germany.
7 : Max Planck Inst Meteorol, D-20146 Hamburg, Germany.
8 : CSIRO, Oceans & Atmosphere, Battery Point, Tas 7004, Australia.
9 : CSIRO Marine Labs, Ctr Southern Hemisphere Oceans Res, Hobart, Tas 7000, Australia.
10 : Antarctic Climate & Ecosyst Cooperat Res Ctr, Hobart, Tas 7001, Australia.
11 : Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 ,USA.
12 : NORCE Norwegian Res Ctr, Bjerknes Ctr Climate Res, NO-5007 Bergen, Norway.
|Source||Proceedings Of The National Academy Of Sciences Of The United States Of America (0027-8424) (Natl Acad Sciences), 2019-06 , Vol. 116 , N. 24 , P. 11646-11651|
|WOS© Times Cited||11|
|Keyword(s)||carbon dioxide, ocean carbon sink, terrestrial carbon sink, climate variability, carbon budget|
Measurements show large decadal variability in the rate of CO2 accumulation in the atmosphere that is not driven by CO2 emissions. The decade of the 1990s experienced enhanced carbon accumulation in the atmosphere relative to emissions, while in the 2000s, the atmospheric growth rate slowed, even though emissions grew rapidly. These variations are driven by natural sources and sinks of CO2 due to the ocean and the terrestrial biosphere. In this study, we compare three independent methods for estimating oceanic CO2 uptake and find that the ocean carbon sink could be responsible for up to 40% of the observed decadal variability in atmospheric CO2 accumulation. Data-based estimates of the ocean carbon sink from pCO(2) mapping methods and decadal ocean inverse models generally agree on the magnitude and sign of decadal variability in the ocean CO2 sink at both global and regional scales. Simulations with ocean biogeochemical models confirm that climate variability drove the observed decadal trends in ocean CO2 uptake, but also demonstrate that the sensitivity of ocean CO2 uptake to climate variability may be too weak in models. Furthermore, all estimates point toward coherent decadal variability in the oceanic and terrestrial CO2 sinks, and this variability is not well-matched by current global vegetation models. Reconciling these differences will help to constrain the sensitivity of oceanic and terrestrial CO2 uptake to climate variability and lead to improved climate projections and decadal climate predictions.