Reducing uncertainty in consequential LCA for circular economy strategies - J-M Lessard - ACLCA 2022 скачать в хорошем качестве

Reducing uncertainty in consequential LCA for circular economy strategies - J-M Lessard - ACLCA 2022

Prioritizing efforts to reduce parametric uncertainty in consequential LCA for large-scale circular economy strategies : Modeling the indirect environmental consequences of large-scale circular economy strategies requires the use of numerous region- and time-specific macroeconomic, technological, market, economic, and environmental inputs. Each input carries a layer of uncertainty that adds unevenly to the multilayer uncertainty of a system. Yet, uncertainty in consequential LCA (CLCA) has not received much attention to date which calls into question the ability of deterministic CLCA models to deliver reliable results. This study aims to explore the parametric uncertainty that most amplifies the variance in marginal life cycle environmental impacts and provide guidance for prioritizing modeling and data collection efforts to improve CLCA reliability. A variance-based global sensitivity analysis based on Monte Carlo simulations is performed focusing on six socio-economic and technology parameter groups (i.e., technological characteristics, demand for materials and products, secondary material generation, costs, interregional transportation costs and emissions) using a CLCA model that is enhanced with a multi-regional and multi-industry circular economic optimization model. The approach is applied to the case of increasing material circularity in cement production in North America. Results show that projected demand levels significantly influence the variance in the environmental impacts for all region types, but the relative importance of model parameters varies with domestic market characteristics. For example, transport inputs have a greater impact on variance in the province of Quebec than in the northeastern United States, which is generally less dependent of cementitious material imports. A generic framework is proposed for prioritizing efforts  to reduce parametric uncertainty in CLCA by region type.