Hi!
When the ocean reaches its saturation level of carbon dioxide, a couple of things will happen:
First, more carbon dioxide will remain in the atmosphere, and second, the ocean's pH will drop.
Carbonate and bicarbonate ions in seawater act as a buffer system which keeps the ocean's pH levels stable. When CO2 dissolves in seawater, it reacts with the ocean's buffer system in such a way that it produces two hydrogen ions, which lowers the pH. As more and more CO2 reacts with the ocean's buffer system and the system becomes saturated, less atmospheric carbon dioxide will cross over into the ocean. This excess CO2 will remain in the atmosphere and contribute to global climate change.
Hope this helped!
