The environmental burden of food waste

Abstract

Food waste is considered a social, environmental and economic problem. Concerns are based, amongst other things, on the environmental damage produced by the food supply chain (FSC) and the substantial amount of food that is wasted.This work reviews the relationship between food waste and the environmental burden of food, aiming to improve our understanding of food waste and its environmental consequences in order to find the most effective solution to reduce environmental burdens of food provision.In this thesis, food waste is defined as any product that was intended for human ingestion but for any reason this was not the case.The topic is studied from three perspectives, utilising multiple methods including input-output and process-base life cycle assessment techniques. First, the available methods to account for the environmental burden of food waste at a country level have been explored. Then, the issues regarding methods to characterise food waste on a broader scale were studied. Lastly, the environmental implications of an alternative food supply chain have been analysed.To characterise environmental burden of food waste at a country level, environmentally-extended input-output analysis has been proposed as the most suitable method available. The proposed technique has been applied to Australia, results show that food waste generated in Australia in 2008 embodied 9% of total water use in Australia and 6% of Australia’s GHG emissions. Most of the water embodied in products was added to the footprint at the farm stage, while GHG emissions are added at different stages with the most significant being farm level and end-of-life emissions. In terms of socio-economic indicators, Australia’s food waste embodied 1% of surplus and also 1% of compensation to employees, which are mostly embodied at the later stages of the food supply chain.Regarding the methods to characterise food waste on a broader scale (country or region) it is identified that when available approaches are applied to Australia, these techniques produced substantially different results. Several data inconsistencies and substantial data gaps to adequately characterise food waste at a country level are identified. To accurately characterise food waste at a country level, this thesis proposes the use of a flexible framework with a mass balance as its primary method, which allows combining multiple and possible conflicting data sources.The assessment of the environmental implications of an alternative food supply chain, working through a “box scheme” is explored through a comparison with a conventional food supply chain. The exercise first estimated the amount of food waste generated for six horticultural products and then compared each supply chains environmental performance using a process-based life cycle assessment technique. Results show that the supermarket supply chain produces significantly more food waste than the alternative food supply chain studied for the horticultural products considered.Food waste is a significant driver for the environmental impact of food provision. By reducing food waste, the environmental impact can also be lowered. The reduction of food waste achieved by the alternative supply chain studied has environmental benefits. For the supply chain analysed, food waste is a more significant contributor to a product's GHG emissions and water use compared with altering transport, packaging and energy for packaging and storage. This means that from an environmental point of view, benefits of scale, regarding transport and storage, achieved by a supermarket, are not as important as reducing food waste.This work has improved our understanding of the relationship between environmental burden of food supply and food waste. It has also proposed methods to estimate food waste at a broader scale and to estimate food waste environmental burden. It highlights the significance of reducing food waste as a tool to reduce environmental issues of food provision and the importance of considering socio-economic aspects when planning for solutions on food waste.