My concern around the ocean as a CO2 sink is how much longer can it absorb CO2 without pH drifting beyond what can support sea life. We keep pulling the elastic band tighter without knowing when it’s going to snap or what happens when it does (metaphorically speaking).
There’s a book called ‘The Sixth Extinction’ By Pulitzer Prize winner Elizabeth Kolbert which talks about this. The sixth chapter is about the rise in ocean acidity.
She also details a critical acidity point (I forget the PH level but I think with current rise in acidity it is modeled to reach that point in 2100) where calcifiers cannot survive due to the acidity essentially breaking down their shells. Think oysters, barnacles, coral. Major parts of the ocean’s ecosystem that could have a ‘cataclysmic’ effect if wiped out.
