Life cycle assessment and waste reduction optimisation of household food waste in Finland

Abstract

This study assessed the environmental impacts of national household food waste in Finland, both the edible (EFW) and inedible (IFW) fractions. The analysis covered the upstream stage, where the food was produced and the end-of-life (EoL) stage, which consisted of waste-to-energy (WtE) and anaerobic digestion (AD). Life cycle assessment with a consequential approach was applied, and a CML baseline was selected as the impact assessment method. An optimisation problem using non-dominated sorting genetic algorithm II was then implemented to investigate the optimum reduction strategy of the EFW. The results showed that the food production stage caused detrimental impacts while the EoL generated environmental benefits due to product substitution. The annual climate change impact from upstream and EoL stages was 0.332 M tonne (Mt) CO2 eq and − 0.05 Mt. CO2 eq, respectively. Beef production was an environmental hotspot in the upstream stage that contributed to about 28 % of climate change impact (0.093 Mt. CO2 eq), although the product was only 3 % of EFW. The hotspots in the EoL stage were energy recovery in WtE (−0.03 Mt. CO2 eq) and petrol substitution in AD (−0.04 Mt. CO2 eq). The optimisation minimised the climate change and cost of EFW when a 50 % reduction was achieved. The optimised solutions decreased 59.5 % climate change impact and 54.6 % cost. The research underlined the importance of quantifying the impacts of food waste as the first step for devising targeted interventions which can be implemented throughout the food supply chain.