Incorporating marine biodiversity impacts of macroplastic debris in life cycle assessments (LCA)

Life cycle assessment (LCA) is a widely utilized sustainability tool for decision-support, offering evaluations of the environmental and human health impacts associated with the whole life cycle of products or processes. However, the standard LCA framework lacks operational methods for quantifying losses and impacts of plastic debris, which effectively means that the analyses assume zero mismanagement and perfect end-of-life scenarios for all plastic products. This assumption does not match with the staggering amounts of plastic ending up as debris in the natural environment yearly, where it poses a well-known threat to marine life. The methodological shortcoming thus limits the analysis of different materials' sustainability and environmental impacts. To address this gap, models to account for leakage and impacts of micro- and macroplastics are under development in the scientific LCA community. As one part of the puzzle, we developed a global model for impacts of entanglement in macroplastic debris on marine mammals, turtles and birds. The model is composed of a Species Sensitivity Distribution (SSD) model along with the geographic ranges of affected species. The fate of buoyant macroplastic on the ocean surface is computed using Lagrangian particle tracking initiated from fishing hotspots within each country's exclusive economic zone (EEZ). We discuss how different release locations and time horizons influence the estimated impact on marine biodiversity and identify further research needs for a comprehensive spatially explicit impact model for macroplastic debris, originating from both land- and sea based sources. The methodology development further highlights the need for detailed inventory data on mismanaged plastic to achieve meaningful analyses. Integrating impacts of marine plastic debris into LCA is imperative to enhance the comprehensiveness of sustainability assessments and can ultimately aid in safeguarding marine ecosystems. Also see: https://micro2024.sciencesconf.org/559584/document