Metrics on the sustainability of region-specific bioplastics production, considering global land use change effects

Expanding the production of fuels and fibres based on traditional food crops can put additional pressures on ecosystems and natural resources, with potential spillover effects through induced land use change (iLUC). Computable General Equilibrium (CGE) modelling provides a systematic framework for ex-ante sustainability analysis, capturing the complex interactions between land uses, agri-food markets, and international trade. This study applies an integrated CGE framework that considers loss of natural vegetation to derive quantitative indicators on the sustainability of manufacturing bioplastics from arable crops in five major producing regions (Brazil, China, the European Union, United States and Thailand). The approach consists of increasing bioplastics production at the cost of conventional plastics in each of these regions separately by means of a production subsidy, simulating bioplastic production targets. In order to assess the uncertainty in sustainability metrics, different levels of market penetration are considered, as well as variability in key model parameters. Increasing bioplastics production in Thailand is in general associated with more favourable metrics, although this is related to the relatively small size of the sector, which triggers minor market-mediated effects. When iLUC is included, increased bioplastics production in China is, on average, associated with the largest land footprint (16.93 ha t(-1)); whereas the highest CO2 emission intensity is estimated for bioplastics produced in the European Union (10.41 t CO2-eq. t(-1)). Emissions from iLUC outweigh potential greenhouse gas (GHG) savings from fossil fuel substitution, except for Thailand, where increasing bioplastics production from sugarcane and cassava saves on average 2.0 kg CO2-eq. t(-1). This translates into decades of carbon payback time and high abatement costs even for Thailand, while trade-offs arise among the metrics proposed. Other impacts besides deforestation and GHG emissions should ideally be considered to examine further interactions within the Water-Food-Energy nexus, though this may require combining global with regionalized approaches, with the associated challenges.

Automated summary

The study applies Computable General Equilibrium (CGE) modeling to assess the sustainability of manufacturing bioplastics in five major producing regions, finding that increasing bioplastics production in Thailand is generally associated with more favorable metrics, while increasing bioplastics production in China is, on average, associated with the largest land footprint.