An Update on Williams’ Carbon Neutrality Claim and Offset Purchasing Strategy

Greenhouse gas (GHG) emissions accounting to determine an organization’s annual net emissions is a reasonably complicated undertaking, not to mention reducing said emissions to stabilize the climate.

Williams College announced in 2015 that it aims to be carbon neutral by 2020. It has maintained this claim since then. The claim rests on two main pillars: (i) accurately measuring Williams’ annual GHG emissions inventory and (ii) zeroing out emissions through a combination of active emissions reductions (e.g., investing in energy efficiency and renewable energy) and purchasing carbon credits in the voluntary carbon market (VCM). Both pillars have constraints and risks that the college, with the support of the Board of Trustees, has decided to further clarify and address.

The first constraint concerns the GHG emissions inventory. It is an annual stock-taking of estimated GHG emissions from the three scopes of emissions using internationally recognized methodologies referred to as the GHG Protocol. Scope 1 considers emissions from sources owned or controlled by the organization (such as the physical plant, college vehicles, refrigerants, and fertilizers). Scope 2 covers emissions associated with the purchase of electricity, steam and/or hot water (in our case this means only grid electricity). Finally, scope 3 covers all other indirect emissions associated with the organization’s operations over which it has no or only limited control. This includes upstream and downstream emissions such as procurement of food, capital goods, employee commuting, student and business travel, waste management, and emissions financed through investments.

Scopes 1 and 2 are relatively straightforward to assess for Williams College, but comprehensively and accurately measuring scope 3 emissions poses real challenges. That is because for many emissions categories in this bucket we have little to no information about the emissions intensity of the products and services that we purchase and the investments we are holding in the endowment. What makes matters worse is that for us and many other organizations, scope 3 emissions make up a large share of total emissions, often exceeding 75 percent. We are currently only able to estimate a subset of these emissions, namely for college-sponsored air travel, food, waste management, and electric power transmission and distribution losses. Together, they made up 36 percent of total emissions in fiscal year 2023.

In addition to the difficulty of comprehensively assessing scope 3 emissions, a GHG emissions inventory is based on specific organizational and temporal boundaries. Temporally, we use the fiscal year but organizationally we have the choice between two boundaries: we can include all assets over which the college has (i) financial control or (ii) operational control. To give an example, a college-owned commercial building on Spring Street would be included in the inventory under (i) but not under (ii) if the tenants make their own decisions about things such as heating, cooling and hot water use. Due to the difficulty of obtaining such usage data, our GHG emissions inventory is compiled using the operational control rule.

Knowing these challenges and accounting practices, how do we claim carbon neutrality? Since fiscal year 2020 we have purchased offsets in the same amount as our GHG emissions inventory estimated. We think it is important to be as transparent and specific as possible about our claim and will, going forward, use carbon neutrality language that is clear about what is included and what is not. In parallel, we will continue our efforts to expand our scope 3 accounting as data availability and quality improves and to actively reduce our emissions.

In conjunction with clarifying our carbon neutrality claim, we also seek to reduce a source of risk in our purchases of carbon offsets. Although we have built a strong working relationship with a carbon offset broker since 2020 and are using the Williams’ Working Group on Carbon Offset’s guidelines for sourcing high quality offsets, we are concerned about the Voluntary Carbon Market’s continued struggles to serve as a credible and effective trading place for carbon credits. So far, we have no information or reason to question the credits we have purchased in the past but we are exploring  sourcing our offsets more systematically and underpinned by deeper analysis. This effort can be facilitated by carbon credit rating agencies, which, similar to rating agencies for other commodities, are conducting in-depth analysis and are presumably also independent arbiters of that analysis. We have not yet made a decision at this time, but are exploring this option, which would also offer some interesting educational opportunities for students interested in the global carbon credit market and project development.

Tanja Srebotnjak, Director of the Zilkha Center for Environmental Initiatives