B6: Ocean acidification: back to the future

(J. Bijma, Bremerhaven; U. Riebesell, Kiel)

Due to the uptake of anthropogenic CO2, world oceans are getting less alkaline (»ocean acidification«) with yet unpredictable consequences for the oceanic ecosystem. The global surface ocean pH has already dropped by 0.1 units since the beginning of the industralisation. In the history of our planet, this is not the first time that oceans have experienced acidification. Eventhough the causes for these events maybe of a different nature (bolide impact at the K/T boundary, methane clathrate release at the PETM and ELMO), and although the rate of change may be different, much may be learned from them. This session aims to provide a biogeoscientific view of past events and future consequences: Can we learn from the geological archives how the present day ecosystem could be affected? Can we learn from the present day ecosystem response to better interprete the archives?