Emergence of anthropogenic signals in the ocean carbon cycle

Schlunegger, Sarah; Rodgers, Keith B.; Sarmiento, Jorge L.; Frölicher, Thomas L.; Dunne, John P.; Ishii, Masao; Slater, Richard (2019). Emergence of anthropogenic signals in the ocean carbon cycle. Nature climate change, 9(9), pp. 719-725. Nature Publishing Group 10.1038/s41558-019-0553-2

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The attribution of anthropogenically forced trends in the climate system requires an understanding of when and how such signals emerge from natural variability. We applied time-of-emergence diagnostics to a large ensemble of an Earth system model, which provides both a conceptual framework for interpreting the detectability of anthropogenic impacts in the ocean carbon cycle and observational sampling strategies required to achieve detection. We found emergence timescales that ranged from less than a decade to more than a century, a consequence of the time lag between the chemical and radiative impacts of rising atmospheric CO2 on the ocean. Processes sensitive to carbonate chemical changes emerge rapidly, such as the impacts of acidification on the calcium carbonate pump (10 years for the globally integrated signal and 9–18 years for regionally integrated signals) and the invasion flux of anthropogenic CO2 into the ocean (14 years globally and 13–26 years regionally). Processes sensitive to the ocean’s physical state, such as the soft-tissue pump, which depends on nutrients supplied through circulation, emerge decades later (23 years globally and 27–85 years regionally).

Item Type:

Journal Article (Original Article)


08 Faculty of Science > Physics Institute > Climate and Environmental Physics
10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)

UniBE Contributor:

Frölicher, Thomas


500 Science > 530 Physics




Nature Publishing Group




BORIS Import 2

Date Deposited:

23 Aug 2021 12:21

Last Modified:

23 Aug 2021 12:21

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