Expanded damage function of stratospheric ozone depletion to cover major endpoints regarding life cycle impact assessment

Background. Stratospheric ozone depletion is one of the important environmental issues for LCIA. The National LCA Project of Japan has developed a framework of LCIA since 1998, which tackles the issue employing an endpoint approach. Although the basic components were available in 2000, it was required that the target endpoints should be expanded in particular. Objective. This study aimed at expanding the scope of damage function of ozone depletion in the LCIA framework of LIME. Damage function gives potential and quantitative damage for each endpoint per unit emission of ODS. Methods. Marginal damage due to the unit emission of ODS was calculated for 13 substances for which quantitative information was available as follows: (1) the increase of UVB radiation at the earth's surface per unit emission of ODS was estimated, (2) the increase of potential damage per unit increase of UVB radiation was estimated, (3) the increase of potential damage per unit emission of ODS was determined by connecting the two relationships, and (4) correcting by the atmospheric lifetime of ODS, so that the damage function was then obtained. For other ODSs regulated by the Montreal Protocol, their damage functions were estimated by multiplying the ratio of ODP compared to the corresponding reference substance by the damage function of this reference substance. Results and Discussion. The damage function of ozone depletion included the following endpoints: skin cancer and cataract for human health, crop production and timber production for social assets, and terrestrial NPP and aquatic NPP for primary productivity. And damage factors for each safeguard subject were also obtained. Conclusion. The damage function of ozone depletion could cover all ODSs regulated by the Montreal Protocol and also cover important endpoints. Uncertainty of damage function is also an important point to be elucidated. Preliminary studies of uncertainty analysis have begun for the damage function of ozone depletion. However, further analysis is required to comprehensively evaluate the uncertainty of the damage function.