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Life-LCA: the first case study of the life cycle impacts of a human being

Bossek, David; Goermer, Marcel; Bach, Vanessa; Lehmann, Annekathrin; Finkbeiner, Matthias

Purpose: Besides politics and the private sector, changes in the consumption pattern of individuals can significantly contribute to sustainable development. The recently published Life-LCA method adapts life cycle assessment to analyse human beings and quantifies their impacts. This method is applied for the first time in this case study to provide insights and remaining challenges. Methods: The environmental impacts caused by the life cycle of a middle-aged German man (“Dirk”) were determined by the Life-LCA method from his birth until his current age (0–49 years). To determine and quantify reduction options, a current 1-year period was analysed in detail by a baseline scenario of his current consumption and an optimized scenario after changing his consumption patterns. The environmental impact assessment included global warming (GWP), acidification (AP), eutrophication (EP), and photochemical ozone creation potentials (POCP). Results and discussion: Dirk has emitted 1,140 t CO 2 -eq., 4.48 t SO 2 -eq., 1.69 t PO 4 -eq., and 0.537 t C 2 H 4 -eq. emissions over his current lifetime. Transportation dominated all considered impact categories (40 up to 55%). Energy and water consumption is the second most significant product category for GWP (39%). Food products, with 10%, are the third biggest contributor to GWP, but contribute rather significantly to the impact categories AP (34%), EP (42%), and POCP (20%). The optimized scenario analysis revealed significant reductions for all studied impacts in the range of 60–65%. CO 2 -eq. emissions were reduced from 28 to 10 t/a. The remaining challenges include data collection for childhood, gaps and inconsistencies of existing data for consumer goods, the allocation between product users, and depreciation of long-living products. Conclusion: The first Life-LCA case study confirmed the applicability of the Life-LCA method. It showed that the Life-LCA approach allows for tracking individual consumption patterns of a human being. The impacts of behavioural changes were quantified, and significant reduction potentials of the environmental impacts were revealed. Additional case studies on people of different age, region, culture, and lifestyle are needed for further insights and methodological refinements.
Published in: The International Journal of Life Cycle Assessment, 10.1007/s11367-021-01924-y, Springer Nature