Food waste amount, type, and climate impact in urban and suburban regions in Finnish households

Abstract

Households produce about half the food waste in Europe, significantly affecting the environment and society. To measure and understand all the impact, there is a need for both primary and direct data, as well as an evaluation of methods. To respond to this need, new knowledge about households' FW and the applicability of waste composition analysis method in urban housing and areas is provided. This knowledge is applicable for planning FW studies, considering various measurement methods, the extrapolation of country-level FW values, and the introduction of decreasing interventions for households. The novelty of this study lies in its comprehensiveness: outcomes from three different city regions are analysed, and the method's robustness is evaluated. The goal of this research was to study the amount and quality of food waste in mixed waste and separately collected biowaste in Finnish households. Other goals were to estimate the unnecessary climate impact of lost food and to assess the validity of the chosen methodology. The study responds to the lack of comprehensive and recent first-hand data and reports results from three different city areas, using a relatively large number of samples that encompass 98,000 inhabitants, or about 50,000 households. The data were collected on four separate occasions: in the Helsinki area during September 2015 and October 2018, in the Turku area during June 2019, and in the Tampere area during September 2016. The results suggested that the average amount of food waste varied between 53.0 kg/cap/y and 62.1 kg/cap/y, and the amount of originally edible food waste varied between 23.0 kg/cap/y and 28.4 kg/cap/y. When extrapolating the food waste results to all study areas, the Helsinki produced about 57,000–62,000 t/y, Tampere about 16,000 t/y, and Turku about 25,000 t/y, for a total of about 100,000 t/y. The Meat and fish type group contributed most to the climate impact of originally edible FW (37–47%), while its share of food waste was much smaller, at 10–12%. The total climate impact was assessed as 0.10 Mt CO2eq/y when the climate impacts per capita annually ranged from 52.9 kg CO2eq/cap/y to 61.4 kg CO2eq/cap/y in the different regions. Due to the results' consistency, the waste composition analysis methodology can be recommended for measuring FW from both mixed and biowaste flows in urban and suburban areas. The study was conducted in cooperation with local waste management companies to increase resource efficiency and the opportunities to share facilities and to decrease study costs.