Scenario Design Methodology for Sustainable Society

Abstract

This paper discusses a scenario design methodology to support system transitions towards a sustainable society. Achieving carbon neutrality and a circular economy requires not only incremental improvements to product life cycles but also a transformation of the entire socio-economic system. To trigger such a system transition, a backcasting scenario approach is often used, where a desirable future vision is envisioned and the pathway to reach the vision is described backward. A distinctive feature of scenario design is its ability to facilitate thought experiments by describing a variety of possible systems in the form of scenarios, free from the constraints of the current system. On the other hand, life cycle evaluation, including LCA, is effective for validating the plausibility of future systems described in the scenarios. Combining scenario design with life cycle evaluation allows for the preliminary evaluation of the feasibility and impacts of proposed designs, making it an effective approach for supporting informed decision-making. However, higher priority in evaluation is placed not on accuracy; rather on identifying the conditions or bottlenecks critical to achieving the goals. Future research topics within the LCA community include exploring combinations of various modeling and evaluation methods for further validating future scenarios, as well as engaging stakeholders through the scenario design and evaluation processes to support practical implementation.