The climate impact of the bread take-back agreement : a scenario-based assessment of decarbonization opportunities along the Swedish bread supply chain

Abstract: Food waste has economic, environmental, and social implications; the importance of reducing food waste is recognized in Sustainable Development Goal 12.3. The Swedish bread take-back agreement (TBA) has been identified as a risk factor for food waste generation at the supplier-retailer interface. The ideal business model for the bread supply chain remains debated, and the implications of the TBA on transport emissions present a research gap. This study compared the climate impact of the conventional take-back agreement for surplus bread in Sweden to a conceptual system with altered logistics and waste management. Life cycle assessment (LCA) with Global Warming Potential (GWP100) as a single impact category was used to analyze alternative scenarios for the Swedish bread supply chain. The results showed that a shift from a TBA system to a non-TBA system in the city of Uppsala increased the climate impact marginally by 5%. Inversely, in other Swedish cities, the non-TBA scenarios clearly outperformed the TBA system, as transport back to the bakery caused 32% higher emissions and the poor re-valorization of bread held a 11% lower emission savings potential. The average GWP100 of all assessed cities is 28% lower for the non-TBA scenarios. The long-distance delivery of bread was identified as an impact hotspot, which points to the necessary decarbonization of the Swedish transport sector. The waste treatment stage offers leverage for emission savings, especially using bread for bioethanol, however, the latter is sensitive to transport distance. For Uppsala, the most prominent benefits come with collaborative approaches that prevent bread wastage in the first place and, at the same time, make use of the clean waste stream created by the TBA.