Influence of CO2 emission rates on the stability of the thermohaline circulation ...

• Main Authors: Stocker, Thomas, Schmittner, Andreas
• Format: Article in Journal/Newspaper
• Language: English
• Published: University of Bern 1997
• Subjects: North Atlantic
• Online Access: https://dx.doi.org/10.48350/158665; https://boris-portal.unibe.ch/handle/20.500.12422/43286

Present estimates of the future oceanic uptake of anthropogenic CO2 and calculations of CO2-emission scenarios (ref 1) are based on the assumption that the natural carbon cycle is in steady state. But it iswell known from palaeoclimate records (ref 2,3,4,5) and modelling studies (ref 6,7,8,9) that the climate system has more than one equilibrium state, and that perturbations can trigger transitions between them. Anticipated future changes in today's climate system due to human activities have the potential to weaken the thermohaline circulation of the North Atlantic Ocean (ref 10,11,12), which would greatly modify estimates of future oceanic CO2 uptake (ref 13). Here we use a simple coupled atmosphere–ocean climate model to show that the Atlantic thermohaline circulation is not only sensitive to the final atmospheric CO2 concentration attained, but also depends on the rate of change of the CO2 concentration in the atmosphere. A modelled increase to 750 parts per million by volume (p.p.m.v.) CO2 within 100 ...