Greenhouse gas reduction potential by household waste prevention

We used a life-cycle assessment (LCA) approach to estimate the greenhouse gas (GHG) reduction effects of preventing 50% of all avoidable household waste in Kyoto City, Japan. The LCA targeted 18 prevention behaviors and 32 avoidable products in household waste. A sensitivity analysis was conducted to determine the impacts of 1% increases in prevention behavior and avoidable product and raw material prevention for reducing GHGs. Compared to the baseline scenario, the prevention scenario demonstrated a 120,000 t CO2eq/y emissions rate in response to preventing 50% of all avoidable products. Improving dietary habits had the greatest GHG reduction effect, followed by avoiding single-use products and beverage and seasoning bottles. Preventing raw materials from food and plastic production substantially reduced GHG emissions. Mitigating the production of avoidable products with and without product substitution contributed to the GHG reduction efficacy of prevention behavior. An additional 1% prevention could increase GHG reductions by 0.56–380 t CO2eq/y per avoidable product and by 13–380 t CO2eq/y per prevention behavior. However, electricity generation via incineration and the GHG emissions intensity associated with producing substituted products would influence the GHG reduction potential.