Environmental impacts and abatement costs of food waste reduction: the case of bread

In this study, environmental impacts and abatement costs of reducing food waste in the life cycle of bread were calculated by connecting life cycle assessment with environmental life cycle costing. The life cycle includes production, processing, sale, consumption and disposal of mixed grain bread in Germany. The functional unit (FU) was set as 1 kg bread consumed. Four scenarios were modelled to examine the costs and impacts of different waste reduction measures: (1) a baseline scenario with no actions taken to reduce food waste, (2) reducing food waste at the retail stage by passing on unsold bread to food banks, (3) reducing food waste at the consumption stage by reducing the amount of bread shopped by 50% followed by a higher frequency of shopping and (4) reducing food waste at the consumption stage by freezing 50% of the bread and consume it to a later point in time. For all scenarios a strong and a weak food waste reduction effect was modelled to show the uncertainties. The life cycle inventory data was analyzed according to the impact categories global warming potential, agricultural land occupation, cumulative energy input and process costs. The calculation resulted in 2.51 kg CO2eq greenhouse gas emissions, 18.04 MJ Energy input,6.69 € process costs and 1.13 m2 a agricultural land occupation per FU for the baseline scenario. The waste reduction measures (2) and (4) scored better than the baseline scenario in almost all impact categories with a strong and also a weak waste reduction effect, while measure (3) had higher greenhouse gas emissions, costs and also energy input (weak effect only) as compared to the baseline scenario. As a conclusion, the assessment of environmental impacts and costs of waste reduction actions should be of high priority when it comes to the choice of food waste reduction measures. Measures should be selected according to their case-specific cost-effectiveness that shows the relation between the abatement costs and resource reductions.

Autoren:
Sandra Baumgardt
Thomas Schmidt 

In: LCAfood 2016. 10th International Conference on Life Cycle Assessment of Food. Dublin, Ireland, 19.-21.10.2016."