Regionalized composition analysis of Norwegian residual waste and its implications for recycling, emission accounting, and food waste avoidance

Residual waste generation within municipal solid waste is characterized as a mix of various waste fractions that are either correctly or incorrectly discarded in residual bins. We denote this as residuals and assess its average and regional composition in Norway, based on the collection of 90 waste composition analysis. There is substantial variability between generation origins, and a clear pattern of lower food waste sorting in urban areas. Greenhouse gas emission of treating the various compositions with waste incineration were assessed, showing that CO2-equivalent emissions vary by up to 13% depending on waste origins, and estimate that approximately 54%, 55%, and 64% of rural, suburban, and urban residuals could potentially be recyclable, with a significant potential for reducing avoidable food waste. Successful implementation of the national “food waste avoidance” strategy could see the avoided generation and consequently production of 110kt of food for Norwegian households. Suggested improvements focus on convenient and clear sorting practices, better resolution on non-household residual compositions, and more multidisciplinary and regionalized research approaches.