The 2015 Paris Agreement has as the central aim to strengthen the global response to the threat of climate change by keeping global temperature rise in this century well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius (United Nations 2015). To reach this ambitious goal, two central strategies have to be implemented in all countries: (i) enhancing energy efficiency (EE) and (ii) decarbonizing remaining energy supply and demand, in particular by large penetration of renewable energy sources (RES). Scenarios with different focuses and assumptions have been developed to map the European energy transition until 2050 (European Commission 2021b). While these scenarios present important tools to support decision makers, much more progress is necessary to quantify the impact of New Societal Trends on future energy demand and greenhouse gas (GHG) emissions.
Industry is responsible for about 22% of Europe’s GHG emissions making the sector critical for the achievement of European climate goals (EEA 2021). It is expected that the circular economy (CE) can contribute significantly to the achievement of these goals while enabling further economic growth (European Commission 2018b, 2019). Considering the challenging decarbonization of the industrial sector and especially the basic material industry, the umbrella concept CE can have great impact on industry transition by reducing virgin material demand and consequently industrial emissions. The concept includes strategies as recycling, material efficiency, material substitution and sufficiency. An ambitious increase in energy and material efficiency in all applications and sectors is a prerequisite for carbon neutral industrial production, as it reduces the final energy demand and thus lowers the costs for the expansion of renewable energies, grid expansion and the import of secondary energy sources.
The following report addresses the aforementioned research needs and describes an improved modeling approach to assess the role of CE as contributor to industry decarbonization. The study focuses on buildings – a typical end-use good – and the associated basic materials steel and concrete. The building value chain was chosen, as it is the main source of demand for two of the highest-emitting materials and has high CE potentials.
The bottom-up industry demand model FORECAST (FORecasting Energy Consumption Analysis and Simulation Tool) is a tool designed to support strategic decision. It calculates scenarios on future energy demand and GHG emissions (all sources incl. process emissions) and the assessment of different technology pathways (Fleiter et al. 2018). However, the model in its current form does not directly consider material flows or the effects of CE endogenously. The suggested method aims to consider cross-sectoral impact via a stock-driven material flow analysis (MFA) linking FORECAST with the building model Invert/EE-Lab (TU Wien et al. 2021). The chosen methodology enables the explicit consideration of CE actions at the relevant stages of the building value chain. In this study, the eight following actions were selected to represent the 9R framework (Kirchherr et al. 2017):
- Using timber instead of (reinforced) concrete in residential buildings;
- Reducing floor space demand in residential buildings and offices;
- Reducing the over-specification of elements by volume;
- Protection of cultural heritage buildings;
- Renovation of existing buildings;
- Reuse of building elements;
- Reuse of building materials;
- Recycling of cement.
