AP, thanks for your time and effort here and it will take me some time to analyze. But your basic gist is clear: the ocean not only has huge heat capacity it also has a tad of PH buffering muscle. And, kinetics increase as a system is forced further out of balance thus the rate of uptake will increase with atmospheric concentration of CO2. And then, when new CO2 is no longer introduced to the system the force of returning to a state of original balance will ensue.
If I can state ATTP’s argument for him it is that the uptake is not dominated by immense oceans but by plant life. And this plant life will cycle the CO2 into the atmosphere (the fast cycle) for some time after man is done with using fossil fuel. And, we will be stuck with it until the marine life sequesters the CO2 by permanent entombment of the carbon in sediments, the “slow cycle.”
I and others were under the impression, because of alarms regarding ocean acidification, that the ocean uptake was the dominate mode of the absorption you outlined quantitatively for us. If that were the case it is straight chemistry and CO2 will continue it’s absorption, acidification likely at the steady state rate that Henry’s Law allows solution of CO2 , (likely cold waters that are less gas saturated).
I suspect the new atmospheric/ocean equilibrium for CO2 will be between 260 and 300ppm due to slightly higher GMST, and it may take several hundred years to return to that range. However, I believe that in several hundred years humankind may not want it to return to those levels for agricultural productively, maintenance of expanded habitats and as a countermeasure against negative Milankovitch trend.
