Circular Economy Policies for Decarbonization of US Commercial Building Stocks: Data Integration and System Dynamics Coflow Modeling Approach

Abstract

Despite the recognition of the built environment as a sector with high potential for reducing embodied emissions, there is a lack of national-level data on embodied carbon emissions attributed to the US commercial building stocks. Hence, there is a need to benchmark the current state of embodied emissions attributed to the commercial built environment and the impact of circular economy (CE) policies for their decarbonization to facilitate well-informed decision-making. This paper fills this knowledge gap through providing policy makers with a framework that estimates the current and future projections of embodied carbon emissions attributable to the US commercial building stocks and highlighting the decarbonization potential of multiple CE policies. To this end, the following multistep research methodology was adopted: (1) collecting and integrating relevant data; (2) conceptualizing and initializing a system dynamics (SD) model; (3) developing subsystems and coflow structures within the SD model using aggregated stock data from the National Energy Modeling System; (4) verifying and testing the developed SD model; and finally (5) suggesting policies and conducting scenario analysis using CE policy precedents. Findings reveal that in the baseline scenario, cumulative emissions are projected to reach 5,605 MtCO2e by 2050. As for the scenario analysis, the unit size reduction policy emerged as the most impactful single policy, achieving a remarkable 38.8% decarbonization. Whereas the comprehensive CE policy that optimizes floorspace demand and the carbon intensity of materials, exhibited a 52% decarbonization potential by midcentury. As such, this study contributes to the body of knowledge by benchmarking emissions projections, providing insights regarding CE decarbonization strategies, their associated primary stakeholders and implementation pathways. Ultimately, by embracing a holistic approach toward CE policies and harnessing accurate and standardized data on building embodied emissions, stakeholders can effectively attain decarbonization goals and promote a sustainable built environment.