Abstract
Urban Metabolism (UM) resembles living organisms in a community by consuming necessities and excreting waste. Using a circular economy concept with UM enhances energy and material circulation and closes waste loops. As a campus metabolism case study, this research tracks energy, food waste, and construction materials flows at Cornell University, Ithaca, NY. These sectors are interconnected at the food and energy systems regarding emissions. The study includes environmental and economic evaluations of proposed food waste mitigation and embodied emission estimation of building stocks. The results suggest that transitioning from natural gas to geothermal is a viable renewable option that can increase circularity. Regarding food waste, the proposed digestate composting reduces emissions by 16 to 39 metric tons of CO2e with a financial gain of 90 to 400 kUS$/y compared to traditional composting practices. Lastly, the comparative assessment of operational emissions from the energy sector and embodied emissions from stored building materials reveals a rising trend in the proportion of embodied emissions contribution, from 53.58 % in 2008 to 73.14 % in 2021. To offset the anticipated release of embodied carbon, Cornell requires strategies to manage construction waste and enhance circularity within this sector. To achieve the decarbonization goal, the campus metabolism study advances the understanding of energy and material flows, emissions, and offsets among the three sectors. This study can unlock sustainability pathways and accelerate Cornell’s progress toward carbon neutrality by 2035.
