Prediction of Acidification in the Ocean Surface, and Benefits and Risks of the CO2 Ocean Sequestration as a Mitigation Technology

To evaluation of benefits and risks of the CO₂ ocean sequestration for prediction of ocean acidification, numerical simulation study was carried out by using the three-dimensional global carbon circulation model. Three scenarios with different amount of the CO₂ ocean sequestration were assumed. One is the reference case which discharges all of CO₂ emission in the world into the atmosphere, the second case is ocean sequestration case which injects into the deep ocean, and third case is joint case of the ocean sequestration and other option such as geological sequestration and use of non-fossil fuel. Amount of CO₂ emission was setup considering B2 scenario until year of 2100 and available fossil fuel after year of 2100. In the ocean sequestration case, the amount of annual emission in the world was divided into seven, and it was injected into each site of layers between 1,000 - 2,000 m. Results of the evaluation, it was suggested that ocean sequestration has the possibility of the suppression of the acidification risk in the whole ocean layer. And it has the possibility of controlling the risk of the increasing atmospheric CO₂ concentration. It is the most important to choose the amount of the isolation of appropriate CO₂ for these achievement.