What I mean is, let's say this process is able to sequester sufficient CO2 in the form of bicarbonate to lower us to a conservative 300ppm CO2. At what point, if any, would we be turning the ph of the ocean to be too alkaline?
Well part of this process is supposed to precipitate out the carbon in forms that can eventually be subducted (as the current natural carbon cycle does).
I assume that the rate at which the carbon is sequestered by this method is also driven by the level of ocean acidity, as more CO2 is pulled out of the ocean the acidity will drop and so will the reaction rate will also drop ... this means that there's a natural negative feedback here - whether it's enough to "do the right thing" is probably still a question for science
