Inclusion of multiple climate tipping as a new impact category in life cycle assessment of polyhydroxyalkanoate (PHA)-based plastics

authored by: Eldbjørg Blikra Vea, Serena Fabbri, Sebastian Spierling, Mikołaj Owsianiak
Abstract: The merits of temporary carbon storage are often debated for bio-based and biodegradable plastics. We employed life cycle assessment (LCA) to assess environmental performance of polyhydroxyalkanoate (PHA)-based plastics, considering multiple climate tipping as a new life cycle impact category. It accounts for the contribution of GHG emissions to trigger climate tipping points in the Earth system, considering in total 13 tipping elements that could pass a tipping point with increasing warming. The PHA was either laminated with poly(lactic acid), or metallized with aluminum or aluminum oxides to lower permeability of the resulting plastics toward oxygen, water vapor and aromas. The assessments were made accounting for potential differences in kinetics of evolution of greenhouse gases (CO₂, CH₄) from bioplastic degradation in the end-of-life. Results show that: (1) PHA films with high biodegradability perform best in relation to the climate tipping, but are not necessarily the best in relation to radiative forcing increase or global temperature change; (2) sugar beet molasses used as feedstock is an environmental hot spot, contributing significantly to a wide range of environmental problems; (3) increasing PHA production scale from pilot to full commercial scale increases environmental impacts, mainly due to decreasing PHA yield; and (4) further process optimization is necessary for the PHA-based plastics to become attractive alternatives to fossil-based plastics. Our study suggests that multiple climate tipping is a relevant impact category for LCA of biodegradable bioplastics.
Organisation(s): Institute of Plastics and Circular Economy
External Organisation(s): Technical University of Denmark
Type: Article
Journal: Science of the Total Environment
Volume: 788
ISSN: 0048-9697
Publication date: 20.09.2021
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Environmental Engineering, Environmental Chemistry, Waste Management and Disposal, Pollution
Sustainable Development Goals: SDG 7 - Affordable and Clean Energy, SDG 8 - Decent Work and Economic Growth, SDG 12 - Responsible Consumption and Production, SDG 13 - Climate Action
Electronic version(s): https://doi.org/10.1016/j.scitotenv.2021.147544 (Access: Open)