We apply LCA methodologies to compare greenhouse gas (GHG) emissions of upcycling, landfilling, and incineration. Critical emission factors for each technology in the upcycling sequence are presented in Figure and are adapted from Ma et al. . All associated product and technology specifications were adapted from literature reports, industry sources, and engineering insight. For the emissions analysis, the global warming impacts of each technology comprise natural gas for heating applications and electricity from the US average national grid, while fuel use in product transportation is accounted for separately. GHG emissions factors for landfilling and incineration are obtained from the Waste Reduction Model (WARM), a US EPA tool that estimates high-level emissions of various waste management practices . Likewise, emission factors for replaced virgin products are estimated with LCA software, including SimaPro databases (see S-Table in the SI). We present direct, unadjusted emissions comparisons, as well as comparisons with emissions credits applied to waste management strategies that create additional valuable products. All methods fulfill the purpose of accepting post-consumer plastic waste, but upcycling produces valuable polymers, and waste-to-energy (WTE) process produces electricity which would otherwise be sourced from the grid. See the SI for further information on system boundaries and approach to emissions data.