抄録
To evaluate whether chronic impacts on biota are caused by 50 Mton CO2 injection per year into the ocean, we simulated transport and dilution of injected CO2 using an offline oceanic general circulation model (OGCM) with a horizontal resolution of 0.1 by 0.1 degrees. Carbon dioxide is continuously injected for 30 years into a site with 1 degree in longitude and 3 degrees in latitude. Most of the CO2 dissolved water is transported in the longitudinal direction. In addition, inter-spatial correlation of the CO2 concentration is relatively higher in the longitudinal direction than in the latitudinal direction. Therefore, a site with large latitudinal width is effective to decrease C02 concentration in order to reduce/avoid biological impacts. CO2 concentration increases first several to 10 years, but shows signs of levelling off after the initial increase. As the simulated maximum CO2 concentration is 80 % of the ” predicted no effect concentration” (PNEC) which is an index to estimate concentration causing no effects on biota, we conclude that 50 Mton CO2 injection per year causes no chronic impacts.
