Simulated 21st century's increase in oceanic suboxia by CO2-enhanced biotic carbon export.

Oschlies, Andreas , Schulz, K. G., Riebesell, Ulf and Schmittner, A. (2008) Simulated 21st century's increase in oceanic suboxia by CO2-enhanced biotic carbon export. Open Access Global Biogeochemical Cycles, 22 (GB4008). DOI 10.1029/2007GB003147.

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Abstract

The primary impacts of anthropogenic CO2 emissions on marine biogeochemical cycles predicted so far include ocean acidification, global warming induced shifts in biogeographical provinces, and a possible negative feedback on atmospheric CO2 levels by CO2‐fertilized biological production. Here we report a new potentially significant impact on the oxygen‐minimum zones of the tropical oceans. Using a model of global climate, ocean circulation, and biogeochemical cycling, we extrapolate mesocosm‐derived experimental findings of a pCO2‐sensitive increase in biotic carbon‐to‐nitrogen drawdown to the global ocean. For a simulation run from the onset of the industrial revolution until A.D. 2100 under a “business‐as‐usual” scenario for anthropogenic CO2 emissions, our model predicts a negative feedback on atmospheric CO2 levels, which amounts to 34 Gt C by the end of this century. While this represents a small alteration of the anthropogenic perturbation of the carbon cycle, the model results reveal a dramatic 50% increase in the suboxic water volume by the end of this century in response to the respiration of excess organic carbon formed at higher CO2 levels. This is a significant expansion of the marine “dead zones” with severe implications not only for all higher life forms but also for oxygen‐sensitive nutrient recycling and, hence, for oceanic nutrient inventories.

Document Type: Article
Research affiliation: OceanRep > SFB 754
OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-BM Biogeochemical Modeling
OceanRep > The Future Ocean - Cluster of Excellence
OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-BI Biological Oceanography
Refereed: Yes
Open Access Journal?: No
Publisher: AGU (American Geophysical Union)
Projects: SFB754, Future Ocean
Date Deposited: 03 Dec 2008 16:52
Last Modified: 31 Jan 2023 05:26
URI: https://oceanrep.geomar.de/id/eprint/7398

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