Background
IPCC AR4 reported that the emission of the anthropogenic Carbon Dioxide (CO2) increase the CO2 concentration in atmosphere after the Industrial Revolution, and increasing of CO2 concentration caused the global warming. Moreover, it is shown that CO2 dissolution into the ocean causes the acidification in the surface layer. The buffering effect of the ocean can suppress the change of the CO2 concentration in the atmosphere. However, the rise of the CO2 concentration in the ocean surface means the pH of seawater decreases. This phenomenon continues until the difference of CO2 partial pressure between the atmosphere and the ocean disappears if the emission of CO2 is stopped. But, the acidification of the ocean progresses as long as it keeps CO2 emission. It is feared that the ocean acidification has crises influence on various organisms and entire ocean ecosystem.
Methods and Results
Carbon Capture and Storage (CCS) is one of the mitigation measure technologies of CO2 emission. Famous carbon storage technology of the CCS using ocean region is sub-seabed geological storage (SGS) and dilution type ocean sequestration (DOS). The evaluation and comparison study for atmospheric CO2 decreasing measure and ocean acidification mitigation measure was carried out using 3-dimensional numerical model with ocean circulation model and a global carbon cycle model based on a lower trophic ecosystem model. The results of the simulation study under the several scenarios showed “SGS without leakage is the best as the effect of measures”. And it is suggested that “There is a possibility of suppressing the ocean surface acidification to more effective by combining DOS with SGS”. This study is supported by the CCS project of RITE under the fund from METI.
Magi, M., 2009. Evaluation study of CCS for the mitigation measure of atmospheric CO2 and ocean acidification by the Global Carbon Cycle Model. Awards Ceremony Speeches and Abstracts of the 19th Annual V.M. Goldschmidt Conference, V.M. Goldschmidt Conference. Geochimica et Cosmochimica Acta 73(13)-1:A815. Supplement.
