Abstract
Artificial carbon dioxide removal (CDR) from the atmosphere has been
proposed as a measure for mitigating climate change and restoring the
climate system to a target state after exceedance (“overshoot”). This
research investigates to what extent overshoot and subsequent recovery
of a given cumulative CO2 emissions level by CDR leaves a legacy in the
marine environment using an Earth system model. We use RCP2.6 and its
extension to year 2300 as the reference scenario and design a set of
cumulative emissions and temperature overshoot scenarios based on other
RCPs. Our results suggest that the overshoot and subsequent return to a
reference cumulative emissions level would leave substantial impacts on
the marine environment. Although the changes in sea surface temperature,
pH and dissolved oxygen are largely reversible, global mean values and
spatial patterns of these variables differ significantly from those in
the reference scenario when the reference cumulative emissions are
attained.