Comparative carbon cycle dynamics of the present and last interglacial

QUATERNARY SCIENCE REVIEWS

卷:137

Article

Brovkin, Victor¹  Bruecher, Tim^1,10  Kleinen, Thomas¹  Zaehle, Sonke²  Joos, Fortunat^3,4  Roth, Raphael^3,4  Spahni, Renato^3,4  Schmitt, Jochen^3,4  Fischer, Hubertus^3,4  Leuenberger, Markus^3,4  Stone, Emma J.⁵  Ridgwell, Andy⁵  Chappellaz, Jerome^6,7  Kehrwald, Natalie⁸  Barbante, Carlo⁸  Jensen, Dorthe Dahl⁹ 

[1] Max Planck Inst Meteorol, Bundesstr 53, D-20146 Hamburg, Germany

[2] Max Planck Inst Biogeochem, D-07745 Jena, Germany

[3] Univ Bern, Inst Phys, Climate & Environm Phys, Bern, Switzerland

[4] Univ Bern, Oeschger Ctr Climate Change Res, Bern, Switzerland

[5] Univ Bristol, Sch Geog Sci, BRIDGE, Bristol BS8 1TH, Avon, England

[6] Univ Grenoble Alpes, LGGE, F-38000 Grenoble, France

[7] CNRS, LGGE, F-38000 Grenoble, France

[8] Univ Venice, CNR, Inst Dynam Environm Proc, I-30123 Venice, Italy

[9] Univ Copenhagen, DK-1168 Copenhagen, Denmark

[10] GEOMAR Helmholtz Ctr Ocean Res, Kiel, Germany

关键词: Carbon cycle;    Climate;    Models;    interglacials;    The Holocene;    The Eemian;    Peatland;    Fire;    Coral reef;   

DOI  :  10.1016/j.quascirev.2016.01.028

来源: Elsevier

【 摘 要 】

Changes in temperature and carbon dioxide during glacial cycles recorded in Antarctic ice cores are tightly coupled. However, this relationship does not hold for interglacials. While climate cooled towards the end of both the last (Eemian) and present (Holocene) interglacials, CO2 remained stable during the Eemian while rising in the Holocene. We identify and review twelve biogeochemical mechanisms of terrestrial (vegetation dynamics and CO2 fertilization, land use, wildfire, accumulation of peat, changes in permafrost carbon, subaerial volcanic outgassing) and marine origin (changes in sea surface temperature, carbonate compensation to deglaciation and terrestrial biosphere regrowth, shallow-water carbonate sedimentation, changes in the soft tissue pump, and methane hydrates), which potentially may have contributed to the CO2 dynamics during interglacials but which remain not well quantified. We use three Earth System Models (ESMs) of intermediate complexity to compare effects of selected mechanisms on the interglacial CO2 and delta(CO2)-C-13 changes, focusing on those with substantial potential impacts: namely carbonate sedimentation in shallow waters, peat growth, and (in the case of the Holocene) human land use. A set of specified carbon cycle forcings could qualitatively explain atmospheric CO2 dynamics from 8 ka BP to the pre-industrial. However, when applied to Eemian boundary conditions from 126 to 115 ka BP, the same set of forcings led to disagreement with the observed direction of CO2 changes after 122 ka BP. This failure to simulate late-Eemian CO2 dynamics could be a result of the imposed forcings such as prescribed CaCO3 accumulation and/or an incorrect response of simulated terrestrial carbon to the surface cooling at the end of the interglacial. These experiments also reveal that key natural processes of interglacial CO2 dynamics - shallow water CaCO3 accumulation, peat and permafrost carbon dynamics are not well represented in the current ESMs. Global-scale modeling of these long-term carbon cycle components started only in the last decade, and uncertainty in parameterization of these mechanisms is a main limitation in the successful modeling of interglacial CO2 dynamics. (C) 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

【 授权许可】

Free