Production-phase greenhouse gases embedded within food loss and waste: magnitude, drivers, and mitigation potential
Porter, Stephen Drummond
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There is considerable loss and waste of food (FLW) all along the agri-food supply chain from the producer through to the consumer. Production-phase greenhouse gas (GHG) emissions are embedded within food that is lost or wasted, increasing the overall carbon intensity of food ultimately consumed. There is limited understanding of the level of carbon inefficiency of food production as a function of loss and waste. The purpose of this thesis is to provide additional clarity on the GHG mitigation potential of addressing food loss and waste. Here, I quantify the embedded production-phase emissions across the food supply chain from multiple perspectives, at varying geographical and temporal scales, and across food commodities. I assess the current and historical context of FLW, how that translates into embedded GHG emissions, and the impact of EU policy and structural barriers within the agri-food chain on FLW. Whilst there is a general scarcity of robust data on FLW or emissions intensity of food production, I find the embedded emissions from avoidable milk waste are about 200 kt CO2e yr-1 in the UK and about 25,000 kt CO2e yr-1 globally, 5.7% and 2.4% of that from respective milk production. I find the embedded emissions of global food wastage increased more than 3-fold in 50 years through 2011 to 2.2 Gt CO2e yr-1 (about 4% of net annual GHG flux of about 50 Gt CO2e in this final year). Emissions grew more quickly than the wastage itself, implying a change in production and dietary preferences towards more emissions intensive foods. Further, per capita FLW emissions increased in developing regions whilst were stable-to-decreasing in developed regions. Deliberate withdrawal and destruction of fresh fruit and vegetables (FFV) from the food supply chain through EU Common Agriculture Policy mechanisms amounted to a cumulative 23,600 kt), with embedded emissions of 5100 kt CO2e for the 26-year period to 2015. This is equivalent to about 2% of EU FFV production and 0.15% of emissions from managed soils in the EU). Despite changes to EU policy resulting in a 95% reduction in such withdrawals, the proportion of withdrawals typically destroyed remained consistent about 60%. This suggests the existence of institutional barriers to the use of non-retail sales channels. Finally, I find up to 4100 kt and 51,500 kt of FLW arise each year from the application of cosmetic standards to FFV within the UK and EEA, respectively. This equates to embedded emissions of up to 970 kt and 22,500 kt CO2e yr-1, about 7% and 14% of UK and EEA managed soil emissions. This research demonstrates considerable absolute production-phase GHG emissions mitigation could be achieved by reducing food loss and waste. Such savings are predicated upon less food being produced to compensate for greater quantities available due to less wastage. Alternatively, greater throughput for the same input could be achieved from improved efficiencies within the agri-food system. Per capita FLW, emissions intensity of food, and possibly food insecurity may all be reduced; a ‘triple-win’ for sustainable production.