Research Publications

This project was conducted to address recommendations from the University of Michigan’s President’s Commission on Carbon Neutrality by footprinting the institution's Scope 3 purchased goods and services greenhouse gas emissions. The research goals were to 1) develop methods for Scope 3 purchased goods and services (PGS) emissions footprinting; 2) partition emissions by spending category to identify high-impact purchasing categories; and 3) identify and recommend procurement system modifications to reduce Scope 3 PGS emissions and streamline progress tracking at the University of Michigan (U-M). The scope of this analysis encompassed all spending for fiscal year (FY) 2020 across all U-M campuses and properties. Procurement data emissions were footprinted using sector-level supply chain emission factors (SEFs) from the 2019EPA Supply Chain Greenhouse Gas Emissions Factors for US Industries and Commodities environmentally-extended input-output model. U-M spending data were disaggregated into spending accounts and assigned SEFs based on the alignment of spending account and SEF industry category descriptions.

Due to the uncertainty of SEF mapping to spending accounts, upper- and lower-bound emissions estimates were calculated by identifying the highest and lowest-impact assignments for each account. The true account footprint is assumed to lie between them. Some accounts saw only one SEF assignment and no bounds were estimated. Results yielded a Scope 3 PGS emissions footprint range of 373-1259 kiloton (kt) CO2e. In many cases, multiple SEFs were assigned to a spending account because we were unable to determine specific spending activities within them. Averages were taken from SEFs assignments for each account, alongside their respective standard deviations. Account averages were summed to produce a total SEF assignment emissions footprint average of 673 kt CO2e. Propagation of uncertainty was calculated at the account group level using the standard deviation statistics for all accounts they contained. Uncertainty also arose from the limited number of SEF categories (405 sectors) available in the EPA tool.

PGS account groups that dominated U-M’s Scope 3 PGS footprint were ‘Laboratory Research Supplies’, ‘General Expenses’, and ‘Plant Operation and Maintenance’. Recommendations fall into two categories: strategies for improved footprint tracking and emissions reductions. Interventions for improved emissions tracking include 1) mapping institutional purchasing account systems by groupings that match or correspond to EEIO emissions factors (e.g., NAICS, UNSPSC); 2) encouraging use of M-Marketsite and incorporating more detailed reporting of purchases when using P-Cards; and 3) updating the mapping of emissions factors to purchasing activities as accounts evolve. Interventions for reducing emissions include 1) shifting to acquiring environmental product declarations (EPDs) to make more sustainable purchasing decisions at the product level; 2) conducting outreach to the wider community of higher education institutions to develop a uniform knowledge base and shared understanding of sustainable procurement practices; and 3) exploring the use of existing asset management software to extract the greatest utility from fewer purchases.