Carbon-water footprints and Socioeconomic Attributes for Urban Infrastructure Renewal and Adaptation

Urban centers are a major greenhouse gas (GHG) emission source in the global carbon budget, making them a focus of climate mitigation and adaptation. Adapting and optimizing carbon-laden inflexible transportation and water supply infrastructure through adaptive urban planning and nature-based solutions (NbS) are important to the transformation of the existing infrastructure framework toward greater resilience and sustainability. Here we propose an iterative framework of systems analysis using conjugate carbon and water footprints, and socioeconomic attributes (e.g., economic cost, environmental justice index) to evaluate adaptation alternatives for optimal climate and social justice co-benefits. In adaptive urban planning, the cascading analysis starts with socio-economic development policies, defining management objectives through stakeholder involvement, followed by estimating carbon and water footprints, adaptation cost, and enviro-economic outcomes for involved population groups. Such analysis results are then used as feedback to iteratively adjust development policies and objectives and to optimize or reconfigure the adaptation options. The adaptation planning toolbox “Smart Urban Designer” (SUD) by EPA (2020) is used to estimate the adaptation attributes of feasible adaptation options including multi-center urban formation, integrated urban-rural water supply, the use of NbS (green space and green infrastructure) in urban renewal, and emergency response to climate extremes. One can further use the adaptive planning results to forecast future urban formation and its associated water demand distribution, analyze corresponding changes in urban hydrology and develop adaptation capacity for underserved populations. Case studies using SUD tools show the importance of such a systems analysis when evaluating and optimizing adaptation options with differential outcomes.