Sources of variation in life cycle assessments of smartphones and tablet computers

Life Cycle Assessment (LCA) studies and reports on smartphones and tablet computers are analysed to detect the sources of variation across their results, considering the impact on global warming potential over 100 years (GWP100). The production and use phases are undoubtedly the life cycle phases contributing most strongly. Existing life cycle inventories (LCI) were analysed to determine the most important components, and a normalization of the use phases was performed. The results highlight the prevalence of the production phase. Integrated circuits (ICs) play a major role, and the estimation of their impact should be thoroughly scrutinized. Finally, the location of the production plants is crucial as electricity generation accounts for a significant part of the GWP. Assumed electricity mixes explain much of the variations in both production and use phases.