摘要
•The circular economy requires a shift from weight-based targets to impact-driven targets.•A new environmental LCA tool is introduced to aid comprehensive policy development.•Whole life cycle thinking is applied to account for the environmental impacts of waste.•A holistic view of the environmental cost of waste is presented which promotes prevention and the circular economy ethos.
Resources and waste strategies have recently seen a shift in focus from weight-based recycling targets to impact-driven policies. To support this transition, numerous decision-support tools were developed to help identify waste streams with the highest impacts. However, the majority of these tools focus solely on greenhouse gas emissions and show a narrow picture of the overall environmental impacts. Furthermore, they cover burdens associated with direct waste management activities and hence fall short when it comes to highlighting the substantial benefits that can be achieved by preventing waste in the first place. This paper quantitatively demonstrates the necessity to adopt impact-based targets that go beyond estimating the greenhouse gas emissions of waste and highlights the substantial benefits of waste reduction and prevention. Using a state-of-the-art waste environmental footprint tool, the paper quantifies the overall environmental impacts of Scotland's household waste and shows how targeting ‘heavy’ materials does not necessarily have the highest overall environmental benefit. Results show that embodied environmental impacts of household waste dominate the total environmental burdens, contributing more than 90% to the whole life cycle impacts, and hence policymakers should prioritise interventions that aim at waste reduction and prevention. Moreover, our analysis shows that food and textile wastes are high-priority materials in Scotland, with the largest contribution to overall environmental burdens; up to 42% and 30%, respectively. Considering the overall environmental impacts of specific waste materials will enable policymakers to develop more granular and targeted interventions to accelerate our transition to a sustainable circular economy.