Global Scenarios of Resource and Emissions Savings from Systemic Material Efficiency in Buildings and Cars

Abstract

Material production now accounts for 23% of global greenhouse gas (GHG) emissions. Resource efficiency and circular economy policies promise emission reductions through reducing material use, but their potential contribution to climate change mitigation has not yet been quantified. Here we present a high-resolution approach for tracking material flows and energy use of products throughout their life cycles, focusing on passenger vehicles and residential buildings. We estimate future changes in material flows and operational energy use due to increased yields, light-weight designs, material substitution, increased service efficiency, extended service life, and increased reuse and recycling. Together, these material efficiency strategies can reduce cumulative global GHG emissions until 2060 by 16-39 Gt CO2e (passenger vehicles) and 28-72 Gt CO2e (residential buildings), depending on climate policy assumptions. The use of wood and more intensive use are promising strategies in residential buildings. Ride sharing and car sharing are best for residential buildings.