Increasing CO2 levels in the atmosphere are lead to a decrease in the oceans pH at CO2 combines with H2O to form Carbonic acid. Carbonic acid dissociates into H+ ions and HCO3- (bicarbonate). The H+ ions go on to combine with CO32- (carbonate ions) and decrease the concentration of these ions. Carbonate ions are required by many organisms for the formation of shells.
Ultimate impact is disruption of ocean ecosystems which can end up impacting society by negatively effecting our food supply chains and beyond that may have economic impacts.
