The case describes Harvard University's consideration to decarbonize its supply chain by replacing cement with a low-carbon substitute called Pozzotive . Developed and produced by Urban Mining Industries, Pozzotive is a ground-glass material made with post-consumer recycled glass. A successful pilot project using Pozzotive could jump start Harvard's initiative to reduce embodied carbon emissions, but Harvard needs credible information about the magnitude and validity of potential carbon reductions. This case illustrates the flow of emissions along a simple supply chain, from Pozzotive to concrete production to Harvard University's construction project. Students explore the different methods of measuring carbon emissions, including the greenhouse gas protocol and the E-liability approach proposed by Professors Robert Kaplan and Karthik Ramanna. The case further features the opportunity to leverage blockchain technology to facilitate the flow of comparable and reliable emissions information.