A committed fourfold increase in ocean oxygen loss.
other · Level V
Where this comes from
- Record sourced from PubMed, PMID 33863893.
- Also identified by DOI 10.1038/s41467-021-22584-4 and PMC identifier 8052459.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
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 thereby lose more than 10% of its pre-industrial oxygen content even if CO<sub>2</sub> emissions and thus global warming were stopped today. In the surface layer, however, the ongoing deoxygenation will largely stop once CO<sub>2</sub> 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.