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Ocean Carbon Cycle Feedbacks Under Negative Emissions
Author(s) -
Schwinger Jörg,
Tjiputra Jerry
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl077790
Subject(s) - environmental science , carbon cycle , climate change , runaway climate change , climatology , greenhouse gas , carbon fibers , tonne , climate model , atmospheric sciences , global warming , climate system , limiting , positive feedback , climate commitment , effects of global warming , oceanography , geology , ecosystem , ecology , geography , computer science , mechanical engineering , electrical engineering , archaeology , algorithm , composite number , engineering , biology
Negative emissions will most likely be needed to achieve ambitious climate targets, such as limiting global warming to 1.5°. Here we analyze the ocean carbon‐concentration and carbon‐climate feedback in an Earth system model under an idealized strong CO 2 peak and decline scenario. We find that the ocean carbon‐climate feedback is not reversible by means of negative emissions on decadal to centennial timescales. When preindustrial surface climate is restored, the oceans, due to the carbon‐climate feedback, still contain about 110 Pg less carbon compared to a simulation without climate change. This result is unsurprising but highlights an issue with a widely used carbon cycle feedback metric. We show that this metric can be greatly improved by using ocean potential temperature as a proxy for climate change. The nonlinearity (nonadditivity) of climate and CO 2 ‐driven feedbacks continues to grow after the atmospheric CO 2 peak.