Thus, ocean acidification not only reduces surface ocean pH, but also reduces the availability of carbonate ion. In seawater, some of the acid (H +) is consumed by reacting with carbonate ion (CO 3 2-) to form bicarbonate ion (HCO 3 -). Carbonate ion is an essential ingredient in the creation of calcium carbonate shells and skeletons produced by a large number of marine organisms (e.g., corals, marine plankton, coralline algae, and shellfish).Ĭarbonic acid is formed as a result of dissolving CO 2 in water. Seawater is naturally ‘buffered’ against these pH changes, but the buffering process consumes carbonate ions.
Click to enlarge.Īs CO 2 reacts with seawater it forms carbonic acid, causing a reduction in seawater pH. Projected atmospheric CO 2 data represent the IPCC IS92a “business as usual” case. of Energy’s Carbon Dioxide Information Analysis Center. Paleo Volstok Icecore and Mauna Loa Observatory data are obtained from the Dept. The top graph calculates the corresponding change in sea surface pH. As a result, dissolved CO 2 in the surface ocean will likely double over its pre-industrial value by the middle of this century, representing perhaps the most dramatic change in ocean chemistry in over 20 million years.Ĭhanges in atmospheric CO 2 over the past 400,000 years and projected to 2100. The global oceans are the largest natural reservoir for much of this excess CO 2, absorbing approximately one-third of that attributed to human activities each year. The rate of increase has also been faster than at any time during that period. Atmospheric carbon dioxide (CO 2) concentrations have increased to the highest level experienced on Earth for at least the past 650,000 years. Over the past two centuries, humans have dramatically altered the composition of the earth’s atmosphere through deforestation and the burning of fossil fuel. The following article is from Coral Reef Watch's introduction to Ocean Acidification (the original of which can be found here):
0 kommentar(er)
