Impacts of anthropogenic carbon emissions on the chemical state of the ocean are quantified for multi-gas emissions scenarios and for idealized emissions and concentration pathways. Mitigation scenarios lead to lower CO2, less climate change, and less ocean acidification than no-climate policy baseline scenarios.
Employing most stringent scenarios yields estimates of ‘minimum warming’ and ‘minimum ocean acidification’ given inertia in the climate and socio-economic systems. Arctic surface water is currently changing from over- to undersaturated conditions with respect to aragonite, a form of CaCO3 secreted by organisms to build their shells and skeletons. For a high 21st century emissions scenario, the volume of supersaturated water, providing habitat to aragonite producers, decreases from preindustrial 42% to 8% by 2300, despite that emissions are stopped in year 2100. Carbon emissions have to be reduced close to zero if atmospheric CO2 is to be stabilized and climate change and ocean acidification to be limited.

Joos F., Frölicher T. L., Steinarcher M., & Plattner G.-K., 2011. Impact of climate change mitigation on ocean acidification projections. In: Gattuso J.-P. & Hansson L. (Eds.), Ocean acidification, pp. 272-290. Oxford: Oxford University Press. Book.