Since the beginning of the industrial revolution, the ocean has absorbed approximately 48% of the anthropogenic CO2 released to the atmosphere, significantly reducing its impact on climate. At current “emissions-avoidance” costs of $10-35 US dollars per ton of CO2 emissions avoided, this represents an ecosystem service worth trillions of dollars. However, this valuable service comes at a steep ecological cost – the acidification of the ocean. As CO2 dissolves in seawater, the pH of the water decreases, making it more acidic. Since the beginning of the industrial revolution, ocean pH has dropped globally by 0.12 pH units. While these pH levels are not alarming in themselves, the rate of change is cause for concern. To the best of our knowledge, the ocean has never experienced such a rapid acidification. By the end of this century, if concentrations of CO2 continue to rise exponentially, we may expect to see changes in pH that are three times greater and 100 times faster than those experienced during the transitions from glacial to interglacial periods. Such large changes in ocean pH have probably not been experienced on the planet for the past 21 million years. How marine ecosystems, coral reefs, and fisheries will respond to this rapid acidification is unknown.
In May 2004, SCOR and UNESCO-IOC co-hosted an international symposium to address these issues and to evaluate what is known about the possible benefits and impacts of CO2 mitigation strategies using the ocean, such as iron fertilization and direct injection of liquid CO2 into the deep ocean. Following this symposium, several international groups requested SCOR and the IOC to keep this issue under review, and the two organizations agreed to make this symposium a regular event to be held every 4 years.
For the 2008 symposium, SCOR and IOC will be joined by two new international organizations: the International Atomic Energy Agency’s Marine Environmental Laboratory and the International Geosphere-Biosphere Programme, enhancing links to the UN system and to interdisciplinary Earth science.
This web-site is a follow-up of the first symposium and is meant to provide a central source of information for ocean scientists on research activities in this area.
The Ocean Acidification Network.
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