Material circularity strategies in the stock-flow-service nexus of buildings, transport, electricity, machinery, furniture, and appliances

Abstract Increasing global population and rising levels of wealth are raising demands for services such as shelter and mobility, leading to greater resource use and environmental impacts. Circular strategies can reduce the resources required for these services. However, the potential of circular strategies to reduce material demand is rarely quantified. Here, we present a method to link service, product, and resource use with circular material reduction strategies. We estimate the potential material reductions for shelter, mobility (including transportation infrastructure), spatial and thermal comfort, and supporting assets such as machinery, and energy infrastructure. We provide a review of the current state of the art on circularity strategies and stock-flow-service (SFS) data availability for the sectors of shelter, mobility (including transportation infrastructure), comfort, and supporting assets such as machinery, and energy infrastructure. We then make a first-order assessment of their theoretical potential for primary material demand reductions by linking them in a counterfactual approach. These show that the current global service provision and supporting assets rely on an in-use material stock of 81 tons per person, with 1.2 ton of materials needed per capita and year to maintain this stock. Current circular strategies could reduce primary material flows by 68% in the absence of rebound effects, economic, policy, or behavioral implications. 15% reduction would be achieved through modal shifts and sharing of products, 31% by slowing the resource flows via longer product lifetimes, and 22% by reusing and recycling materials. This analysis and extensive data repository serve as a starting point for more detailed multi-sector future projections.