Lukas Messmann

The ozone molecules in Earth's stratosphere protect life on Earth by absorbing ultraviolet light. However, inert chemicals such as chlorofluorocarbons (CFCs), other halocarbons, and nitrous oxides destroy ozone in catalytic reactions when reaching the stratosphere. This dramatic environmental problem was recognized internationally as a direct consequence of anthropogenic activities after the discovery of the Antarctic “ozone hole” in 1985. As a response, the UN signed the Montreal Protocol in 1987, mandating the phase-out of many ozone-depleting substances (ODS). Despite treaty violations, uncertainties in emission trends since the mid-2010s, and rising N2O emissions, the Montreal Protocol can be considered a success story of international cooperation and scientific rigor. This entry summarizes how ozone depletion is integrated into common LCIA methods, to which product families LCA researchers should pay close attention, how ozone depletion compares with climate change and other impacts, and where trade-offs between climate change mitigation and ozone layer protection exist.

Bioeconomy is often cited as one pathway toward sustainable materials and a circular economy in an urban–rural context. This study conducts a life cycle sustainability assessment (LCSA)—life cycle assessment, social life cycle assessment, and life cycle costing (LCC)—to assess the benefits and impacts of substituting fossil polymer‐based products with biogenic alternatives through two product systems: drinking cups and insulation boxes. In detail, we assess the environmental impacts, social hotspots, and societal costs subject to various product characteristics. The latter comprises, among others, different materials (fossil‐based polymers, first‐generation and second‐generation biomass), allocation scenarios, electricity mixes, use cycles, and end‐of‐life (EoL) quotas. The LCSA is conducted with primary data provided by industry partners and secondary data from ecoinvent, the social hotspots database, and the literature. The results show that the drinking cup from second‐generation bio‐polyethylene (bio‐PE) performs best in most environmental impact categories, followed by the fossil‐based polypropylene (PP) cup. When substituting PP cups with bio‐PE cups, 32% of CO ₂ eq. emissions and 37% of water can be saved, while land use and particulate matter emissions increase by 37% and 7%, respectively. Due to low recycling rates in the status quo, cups made of polylactide acid—a first‐generation bio‐based polymer—often have higher environmental impacts than fossil‐based ones. Governance and health and safety are the most prominent social categories and are especially linked with raw materials transportation. Similar trends are observed for the insulation box product system. The study identifies improvements in EoL practices, using biomass as‐is, and regional sourcing as essential for enhancing bio‐based materials' sustainability.