Reducing material use and their greenhouse gas emissions in the Greater Oslo

Resource efficiency strategies are key to reduce material use and help limit global warming to below 2°C in 2100. Understanding the role of such strategies at municipal-level requires a localized approach. Here we evaluate a ramp-up of resource efficiency strategies and their associated effects on vehicle usage and climate benefits towards 2050 for 19 individual sub-regions within the Greater Oslo region in Norway. In our scenarios, material stocks increase from 344 megatonnes (Mt) in 2022 to 349-367 Mt in 2050 driven by population growth, with low-end estimate relying on a sufficiency scenario limiting floor area per capita and banning new single-family houses. The sufficiency (SUF) scenario reduces total material consumption until 2050 (48 Mt) with 28% relative to a business-as-usual (BAU) scenario (66.3 Mt) with continuation of ongoing trends, thereby reducing GHG emissions from material production by 17% (BAU: 12.44 MtCO2-eq, SUF: 10.36 MtCO2-eq). If resource efficiency strategies are combined with rapid material production decarbonization in-line with a 2°C scenario, a 30% reduction in emissions is achievable (8.67 MtCO2-eq). Car ownership rates and traveled distance per capita decrease in the sufficiency scenario compared to 2022 with 6.4%. Assuming the current relationship between settlement characteristics and transport demand, total driving distance fails to decline due to population growth. Limiting the floor-area per capita in residential buildings significantly decreases material demand. Resource efficiency strategies including densification need to be complemented with a rapid decarbonization of material supply and stronger incentives to move away from car driving to maximize climate change mitigation.