A committed fourfold increase in ocean oxygen loss

This study uses millennial-scale model simulations to show that less than a quarter of the ultimate ocean deoxygenation caused by historical CO2 emissions has been realized. Even if CO2 emissions were stopped in 2020, the deep ocean would still lose more than 10% of its pre-industrial oxygen content due to a sluggish overturning circulation increasing water residence times. Surface layer deoxygenation would largely cease with the halt of emissions. Combined effects of committed oxygen loss and warming reduce metabolic viability for marine animals by up to 25% in large deep ocean regions, posing a significant threat to deep-ocean ecosystems.

Andreas Oschlies