Artificial upwelling is a technology aiming to increase the marine productivity by uplifting bottom seawater with rich nutrient to euphotic zone using artificial structure. The environmental impacts of an artificial upwelling technology using a seabed mound is inclusively assessed by using the Triple I (III: Inclusive Impact Index). Triple I is calculated based on ecological footprint (EF),biocapacity, ecological risk, human risk, cost, and benefit. In the calculation of EF, environmental impacts due to CO2 emission is estimated using input-output analysis considering indirect effects through the whole economy, which could be several times larger than the direct effects. It is also found that increase of biocapacity due to the enhancement of primary production will much greater than EF increase due to the construction of seabed mound. The value of III could significantly affected by the parameter γ which converts economic value (cost or benefit) to environmental value (EF). Based on a detail consideration about the parameter , a new method to calculate γ was proposed in which marginal abatement costs of CO2 emission and GDP produced by each industrial categories are utilized. III with proposed γ indicates that the artificial upwelling technology will be sustainable when the indirect effect is considered.