Long-term response of oceans to CO2 removal from the atmosphere

Carbon dioxide removal (CDR) from the atmosphere has been proposed as a measure for mitigating global warming and ocean acidification. To assess the extent to which CDR might eliminate the long-term consequences of anthropogenic CO2 emissions in the marine environment, we simulate the effect of two...

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Bibliographic Details
Published in:Nature Climate Change
Main Authors: Mathesius, Sabine, Hofmann, Matthias, Caldeira, Ken, Schellnhuber, Hans Joachim
Format: Article in Journal/Newspaper
Language:English
Published: Nature Publishing Group 2015
Subjects:
Online Access:https://oceanrep.geomar.de/id/eprint/30925/
https://oceanrep.geomar.de/id/eprint/30925/1/Mathesius.pdf
https://oceanrep.geomar.de/id/eprint/30925/2/nclimate2729-s1.pdf
https://doi.org/10.1038/NCLIMATE2729
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Summary:Carbon dioxide removal (CDR) from the atmosphere has been proposed as a measure for mitigating global warming and ocean acidification. To assess the extent to which CDR might eliminate the long-term consequences of anthropogenic CO2 emissions in the marine environment, we simulate the effect of two massive CDR interventions with CO2 extraction rates of 5 GtC yr(-1) and 25 GtC yr(-1), respectively, while CO2 emissions follow the extended RCP8.5 pathway. We falsify two hypotheses: the first being that CDR can restore pre-industrial conditions in the ocean by reducing the atmospheric CO2 concentration back to its pre-industrial level, and the second being that high CO2 emissions rates (RCP8.5) followed by CDR have long-term oceanic consequences that are similar to those of low emissions rates (RCP2.6). Focusing on pH, temperature and dissolved oxygen, we find that even after several centuries of CDR deployment, past CO2 emissions would leave a substantial legacy in the marine environment.