GEOMAR Helmholtz Centre for Ocean Research Kiel, 24105, Kiel, Germany.
Kiel University, 24098, Kiel, Germany.
Nat Commun. 2021 Apr 16;12(1):2307. doi: 10.1038/s41467-021-22584-4.
Less than a quarter of ocean deoxygenation that will ultimately be caused by historical CO emissions is already realized, according to millennial-scale model simulations that assume zero CO 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 emissions and thus global warming were stopped today. In the surface layer, however, the ongoing deoxygenation will largely stop once CO 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.
根据假设 2021 年以后 CO 排放量为零的千年尺度模型模拟，由历史 CO 排放最终导致的海洋脱氧作用不到四分之一已经显现。约 80%的既定耗氧作用发生在 2000 米以下深度，那里更为缓慢的翻转环流会增加水的停留时间和呼吸耗氧的积累。根据模型结果，即使今天停止 CO 排放和全球变暖，深层海洋也将损失超过 10%的工业化前含氧量。然而，在表层，一旦停止 CO 排放，正在进行的脱氧作用将在很大程度上停止。考虑到既定耗氧损失和海洋变暖的共同作用，海洋动物的代谢生存能力在深层海洋的大部分地区下降了多达 25%，这对深海生态系统造成了不可避免的人为压力的升级。
