We established the inflow-driven dynamic Material Flow Analysis model MISO2 to calculate accumulation of global stocks at national levels for 1900-2016. MISO2 discerns 23 raw materials, 14 supply-chain processes (processing, trade, use, recycling, waste management), and 13 stock types. MISO2 is fully mass-balanced and includes an uncertainty assessment. It is used to calculate material stocks in countries based on material flow data, as well as for a range of other applications (incl. follow-up projects) assessing progress towards the circular economy and various scenarios. Precursors of the model were used to study past and future stock-flow dynamics and generate insights into potentials of a more circular economy, as well as on future GHG budgets.
We developed other models based on the stock-driven approach (calculation of stocks e.g. based on volume of buildings or length of roads). This approach generates in-depth information on specific end-uses across scales, e.g. GHG emissions and material requirements of future scenarios of global electricity infrastructures and global mobility infrastructures, and allows generating stock maps.
We mapped material stocks wall-to-wall over large areas at high resolution (e.g. entire countries at 10m resolution). This required methodological innovations in assessing the height of buildings and integrating data from remote sensing, earth observation, and empirical studies of building mass per unit area or volume. We mapped the mass of material stocks in several countries (Austria, Germany, the UK and the USA) and, in modified form, global infrastructures and buildings.
We tackled several conceptual questions. Considerable progress was made in understanding services, e.g. we proposed the energy-service cascade. We developed the complementary stock-flow-practice nexus approach underpinning interdisciplinary collaborations with social scientists and historians, and contributed several papers on provisioning systems, a concept used in studying resource requirements for social wellbeing. Our systematic review of the eco-efficiency literature resulted in publications that were prominently cited in chapter 5 of the IPCC-AR6-WGIII report as well as in discussions on eco-efficiency, decoupling and degrowth.
We analyzed how stocks help understanding the malleability of social metabolism. We found that built structures are co-determinants of resource use; changing their future patterns (e.g. reducing urban sprawl) can be an important lever towards sustainability.
Results were not only disseminated in dozens of research articles, lectures and presentations, but also in newspapers, broadcasts, etc., as well as through collaborations with the arts, among others through an exhibition in the Museum of Applied Arts in Vienna, as part of the Vienna Biennale for Change 2021, and the 2024 Vienna Climate Biennale.
MAT_STOCKS enabled the applicant to successfully apply for a range of projects, including a large (7M€, 5yr) project funded by the Austrian Science Fund. Insights support the planned monitoring of material stocks by the European Environment Agency (EEA).
