CO2 effect: focus on marine fauna

The oceans absorb more than a quarter of carbon dioxide in the atmosphere, which dissolves in the water to form carbonic acid. This way, the oceans act as a carbon dioxide sink. However, as the amount of greenhouse gas increases in the atmosphere, so does the amount of carbonic acid in the waters, leading to ocean acidification (OA). corals and echinoderms (like starfish) face endangerment and extinction, respectively, by 2100. Corals spend their entire life in one place and cannot efficiently compensate for higher acidity as they lack the necessary physiological mechanisms.These organisms also secrete calcium carbonate to create the most productive ecosystems known: coral reefs. Higher OA and warmer climes could interfere with the formation of reefs, with the scientists believing they could face extinction by the end of the century. OA could also reduce the amount of biogenic emissions of sulphur compounds like dimethylsulphide. Though not a greenhouse gas, dimethylsulphide cools the atmosphere by reducing the amount of solar energy reaching Earth’s surface. If its concentration is diminished, it could result in ocean acidification directly adding to global warming.