Record Details
Field | Value |
---|---|
Title | Simulated 21st century’s increase in oceanic suboxia by CO2-enhanced biotic carbon export |
Names |
Oschlies, Andreas
(creator) Schulz, Kai G. (creator) Riebesell, Ulf (creator) Schmittner, Andreas (creator) |
Date Issued | 2008 (iso8601) |
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. |
Genre | Article |
Identifier | Oschlies, A., K. G. Shulz, U. Riebesell, and A. Schmittner (2008), Simulated 21st century’s increase in oceanic suboxia by CO2-enhanced biotic carbon export, Global Biogeochem. Cycles, 22, GB4008, doi:10.1029/2007GB003147. |