Many scientists view the world's oceans as an important sink for capturing the human-induced greenhouse gas CO2 and slowing global warming. Marine plants soak up CO2 as they breathe it in and convert it to food during photosynthesis. Organisms also use it to make their skeletons and shells, which eventually form sediments. With the explosion of fossil-fuel burning over the past 200 years, it has been estimated that more than a third of the human-originated greenhouse gas has been absorbed by the oceans. While marine organisms need CO2 to survive, work by Caldeira and colleagues shows that too much CO2 in the ocean could lead to ecological disruption and extinctions in the marine environment.
When CO2 gas dissolves into the ocean it produces carbonic acid, which is corrosive to shells of marine organisms and can interfere with the oxygen supply. If current trends continue, the scientists believe the acidic water could interrupt the process of shell and coral formation and adversely affect other organisms dependent upon corals and shellfish. The acidity could also negatively impact other calcifying organisms, such as phytoplankton and zooplankton, some of the most important players at the base of the planet's food chain.
"We can predict the magnitude of the acidification based on the evidence that has been collected from the ocean's surface, the geological and historical r
Contact: Dr. Ken Caldeira