Identification of most relevant characterization factors to be regionalized in Brazil
Cássia Maria Lie Ugaya, Fernando C. Cuzinsky
In Life Cycle Assessment studies, many impact categories, as acidification, eutrophication, smog and water scarcity, depend on regional conditions, demanding regionalized characterization factors (CFs). Regionalization of CFs was identified as an important topic by the Brazilian Life Cycle Impact Assessment Research Network, the Brazilian LCA Programme and by the attendees of the Brazilian LCA Forum to improve the results obtained in LCA in the country. CFs are used in LCAs to obtain the potential environmental impacts of products and organizations. In a former study, it was noticed that few elementary processes contribute with most of the impact. As regionalizing may rely upon huge amount of data, that are not always available, data processing and assessment, the aim of this study is to identify the impact categories and elementary flows responsible for most of the impact. With this purpose, sensitivity analysis (SA) has been used in several LCA studies, but very few based on perturbation analysis and mostly to assess the inventory. The list of main products was obtained from the Brazilian Institute of Geography and Statistics and the relation to ecoinvent products was performed according to a previous study. Then, the relative perturbation of the CFs to 417 impact categories (except climate change, ozone depletion and resources) available in ecoinvent v.3 was calculated in MatLab. The results showed that among the impact categories, 3 presented sensitivity higher than 10, most of them related to ecosystem quality and land use. Moreover, among the 84,686 CFs, less than 0,1% has a perturbation higher than 1 and less than 0,5%, higher than 0,5 (almost 60% related to resource). All in all, the results of the study showed that very few impact categories and elementary flows are sensitive to changes and the efforts to regionalize of the CFs could be based on this list.