Sector‐specific scenarios for future stocks and flows of aluminum: An analysis based on shared socioeconomic pathways

ABSTRACT: Aluminum is an energy-intensive material that is typically used as an alloy. The environmental impacts caused by its production can potentially be spread out over multiple uses through repeated recycling loops. However, inter-alloy contamination can limit the circularity of aluminum, which highlights the importance of analyzing prospective stock dynamics of aluminum at an alloy and alloying element level to inform a more sustainable management of this resource. A dynamic material flow analysis (MFA) of aluminum alloys was developed in line with the shared socioeconomic pathways (SSP) framework to generate consistent scenarios of the evolution of aluminum stocks and flows from 2015 to 2100 covering 11 economic sectors in 5 world regions. A sector-specific and bottom-up modeling approach was developed. Results show no saturation of global stock per capita before 2100, reaching a range between 200 and 400 kg per capita according to different socioeconomic scenarios. For the business-as-usual scenario, the global annual inflow rises to 100 Mt in 2050 and peaks at 130 Mt in 2090, showing a saturation in total stock. Electricity-sector demand has the highest relative growth over the century, while building and construction demand saturates and decreases from 2090. No major mismatch between inflows and outflows of aluminum alloy is observed. This means that with appropriate dismantling and sorting, changes in alloy demand would not limit the implementation of a closed-loop aluminum industry. This study demonstrates the advantages of combining detailed MFAs and SSPs, both for greater consistency in circular economy modeling and for furthering scenario development efforts