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A committed fourfold increase in ocean oxygen loss.

ABSTRACT: Less than a quarter of ocean deoxygenation that will ultimately be caused by historical CO₂ emissions is already realized, according to millennial-scale model simulations that assume zero CO₂ emissions from year 2021 onwards. About 80% of the committed oxygen loss occurs below 2000 m depth, where a more sluggish overturning circulation will increase water residence times and accumulation of respiratory oxygen demand. According to the model results, the deep ocean will thereby lose more than 10% of its pre-industrial oxygen content even if CO₂ emissions and thus global warming were stopped today. In the surface layer, however, the ongoing deoxygenation will largely stop once CO₂ emissions are stopped. Accounting for the joint effects of committed oxygen loss and ocean warming, metabolic viability representative for marine animals declines by up to 25% over large regions of the deep ocean, posing an unavoidable escalation of anthropogenic pressure on deep-ocean ecosystems.

SUBMITTER: Oschlies A

PROVIDER: S-EPMC8052459 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature

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A committed fourfold increase in ocean oxygen loss.

Oschlies Andreas A

Nature communications 20210416 1

Less than a quarter of ocean deoxygenation that will ultimately be caused by historical CO<sub>2</sub> emissions is already realized, according to millennial-scale model simulations that assume zero CO<sub>2</sub> emissions from year 2021 onwards. About 80% of the committed oxygen loss occurs below 2000 m depth, where a more sluggish overturning circulation will increase water residence times and accumulation of respiratory oxygen demand. According to the model results, the deep ocean will there ...[more]

PMID: 33863893

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