Why does carbon dioxide act as a buffer in seawater?

The oceans play an important role in regulating the amount of CO 2 in the atmosphere because CO 2 can move quickly into and out of the oceans. Once in the oceans, the CO 2 no longer traps heat. CO 2 also moves quickly between the atmosphere and the land biOSphere (material that is or was living on land).Of the three places where carbon is stored---atmosphere, oceans, and land biOSphere---approximately 93 percent of the CO 2 is found in the oceans. The atmosphere, at about 750 petagrams of carbon (a petagram [Pg] is 10 15 grams), has the smallest amount of carbon