Sensitivity analysis as a tool to extend the applicability of LCA findings

Life cycle assessment (LCA) results are often used to communicate the environmental impacts of products and measure environmental performance for comparison between different options on the market. Sensitivity analyses are a routine part of LCA but often used with a narrow focus. In a case study on foodstuff packaging, the environmental performance of two food cartons in comparison with competing packaging solutions, i.e. food cartons, glass jars, steel cans, plastic pots and retortable pouches, was examined. Furthermore, the benefits of additional sensitivity analyses as a tool to model country-specific conditions to extend the applicability of LCA findings across a number of systems were evaluated. A cradle-to-grave LCA in compliance with ISO standards 14040 and 14044 for the European market (EU27 + 2) was performed. The study was accompanied by a critical review process. The choice of the analysed packaging systems was made according to the European market share. Relevant processes were modelled with primary input data wherever possible; otherwise, average data from public LCI databases were applied. A wide range of environmental impact categories were covered: Climate Change, Ozone Depletion Potential, Summer Smog, Acidification, Eutrophication, Human Toxicity: PM10 and Abiotic Resource Depletion. To comply with ISO standards, a sensitivity analysis on allocation was performed. In addition, sensitivity analyses on recycling rates were included. The primary environmental impacts for both food cartons arose from base material production for primary packaging. The environmental performance of the food cartons compared favourably with all competing systems for virtually all examined impact categories, primarily due to the fact that primary packaging materials for food cartons are derived from renewable resources. The additional sensitivity analyses quantifying the influence of end-of-life management did not change overall results yet revealed trajectories that could be indicative of trends in a range of different settings from no to complete recycling. Thus, the additional sensitivity analyses revealed a robust result that may be informative in circumstances that depart from European settings. Both food cartons show a superior performance in comparison with alternatives. The sensitivity analyses on recycling rates confirm this result even with very low or high quotas applied. These analyses provide valuable information on how different parameters depending on different geographic scopes may influence the overall results. Future LCA work would benefit from low-effort additional sensitivity analyses to broaden applicability of results and examine the robustness of findings.