Food waste recycling in the USA can reduce climate and nutrient pollution impacts yet risks plastic accumulation in soils
摘要
Diverting food waste to composting and anaerobic digestion can reduce landfill methane emissions and contribute towards a circular bioeconomy, but trade-offs can be incurred from nutrient loading to aquatic ecosystems and contamination from plastic packaging. Here we used mass balance modelling and life cycle assessment to compare the climate, nutrient loading and plastic pollution impacts of current landfill-dominant US food waste management with hypothetical organics recycling scenarios. We estimate that nationwide implementation of organics recycling could reduce the climate impact of US food waste management by 89–99%, and associated nitrogen and phosphorus loading to downstream waterways by 49–54% and 78–98%, respectively, relative to current landfill-dominant practices. However, land application of food waste-derived composts and digestates would offset <2% of US mineral nitrogen and phosphorus fertilizer consumption annually and, without innovations in food packaging design, could discharge ~20,000 t of plastic to US agricultural soils each year.