Dickson Prize in Science
Honoring François M.M. Morel
March 4, 2013
Albert G. Blanke Professor of Geosciences
Award Ceremony and Lecture
McConomy Auditorium, first floor, University Center
Ocean Acidification: Causes, Time Scales and Consequences
The dissolution of anthropogenic carbon dioxide into the ocean causes the water to become more acidic, leading to a variety of direct and indirect effects on the chemistry of surface seawater and the physiology of its inhabitants. How this ocean acidification, which has been called “global warming's evil twin" will affect marine ecosystems is a topic of active research and much debate. Some predict wholesale changes in primary production, crashes in fisheries stocks and the disappearance of coral reefs. Others believe that marine ecosystems will adapt and that no major effects should be expected. What makes such predictions particularly difficult is the century time scale of ocean acidification, much longer than the laboratory or field experiments we can carry out, and much shorter than the resolution of our geological records for similar events in the Earth’s distant past. Our best hope to assess the likely consequences of ocean acidification rests with a mechanistic approach in which the physiological and biochemical effects of the predictable changes in chemistry are studied at the molecular level.This will be exemplified by a series of examples in which we examine the consequences of increasing the CO2 concentration and decreasing the pH on key processes such as photosynthesis, the precipitation of calcium carbonate and the fixation of atmospheric nitrogen.