Assessing greenhouse gas emissions from university purchases

A greenhouse gas (GHG) inventory was conducted for Yale University's procurement of goods and services over a one‐year period. The goal of the inventory was to identify the financial expenditures resulting in the greatest “indirect” GHG emissions. This project is part of an ongoing effort to quantify and reduce the university's environmental impacts.

The impacts of institutional purchases were analyzed using publicly available economic input‐output life cycle assessment software. This model allows users to estimate the indirect GHG emissions of procured goods and services using expenditure data for different categories of purchases. The results are based on national averages for the USA.

The findings of this inventory indicate that indirect GHG emissions from procured goods and services are the greatest source of the university's emissions. A total of 15 of the university's 142 financial expenditure categories accounted for 80 percent of the GHG emissions. Many of these categories were expected, including energy purchases, construction activities, and air travel. Others were more surprising, particularly architectural and engineering services, laboratory supplies, and software.

This study is expected to assist Yale University in its efforts to reduce GHG emissions by providing a quantitative basis for prioritizing green supply chain management decisions.

This study demonstrates that universities and other organizational entities can proficiently assess indirect GHG emissions from goods and services using publicly available software, and that these efforts are significant for understanding the environmental impacts of higher education.