Up to now, the oceans have buffered climate change considerably by absorbing almost one third of the worldwide emitted carbon dioxide. The oceans represent a significant carbon sink, but the uptake of excess CO2 stemming from mans burning of fossil fuels comes at a high cost: ocean acidification.
Research on ocean acidification is a newly emerging field and was one of the major topics at this years European Geosciences Union (EGU) General Assembly held in Vienna in April. The European Science Foundation EUROCORES (European Collaborative Research) programme EuroCLIMATE, which addresses in particular global carbon cycle dynamics, organized and co-sponsored several sessions on ocean acidification.
The chemistry is very straight-forward: ocean acidification is linearly related to the amount of CO2 we produce. CO2 dissolves in the ocean, reacts with seawater and decreases the pH. Since the industrial revolution, the oceans have become 30 percent more acidic (from 8.2 pH to 8.1 pH). Under a business as usual scenario, predictions for the end of the century are that we will lower the surface ocean pH by 0.4 pH units, which means that the surface oceans will become 150 percent more acidic and this is a hell of a lot , said Jelle Bijma, chair of the EuroCLIMATE programme Scientific Committee and a biogeochemist at the Alfred-Wegener-Institute Bremerhaven. Ocean acidification is more rapid than ever in the history of the earth and if you look at the pCO2 (partial pressure of carbon dioxide) levels we have reached now, you have to go back 35 million years in time to find the equivalents continued Bijma. A maximum allowed change in pH, where the system is still controllable, needs to be found. This is a major challenge considering the multifaceted unknowns that still are to be clarified. This so-called tipping point is currently estimated to allow a drop of about 0.2 pH units, a value that could be reached in as near as 30 years. More research and further m
|Contact: Dr. Michiko Hama|
European Science Foundation