Climate change or no climate change, there is one consequence that is in no doubt: As the concentration of CO2 in the atmosphere increases, so will its concentration in the ocean – resulting in ocean acidification.
When CO2 dissolves in seawater it reacts to form a number of ionic and non-ionic carbon species depending on the temperature and alkalinity. The net effect is to increase the concentration of hydrogen ions (H+) and reduce the concentration of carbonate ions (CO3 2– ). More H+ ions mean lower pH and more acidic conditions; so as more and more CO2 dissolves into the ocean, the ocean is becoming more and more acidic. Reducing the carbonate ions means that calcifying organisms, those that form shells and coral reefs, have to spend increasing amounts of energy on this activity, at the expense of growth and reproduction causing long-term changes to ecosystem structure and function.
Tagliabue A., & Monteiro P., 2011. The southern annular mode and the weakening of the Southern Ocean CO2 sink. CSIR ScienceScope November 2011: 24-25. Article.
