Williams College's Carbon Offsets Purchases

In 2007, Williams College set its first climate goals to reduce emissions to 10% below 1990 levels by 2020 and to establish sustainability as an institutional priority.  In 2015, President Adam Falk and the Board of Trustees revised and expanded the college’s commitment to address climate change. The two parts of this commitment related to the campus’s greenhouse gas emissions include: 1) reduce the college’s emissions to 35% below 1990 levels and, after doing that, 2) purchase sufficient carbon offsets to achieve carbon neutrality.  Progress towards meeting the first part of the goal can be seen in our most recent emissions report.  

As for the second part of the goal, the Campus Environmental Advisory Committee (CEAC) spent the 2017-2018 and 2018-2019 academic years discussing and debating the approach that the college should take to carbon offsets. 

But what exactly are carbon offsets?  “Carbon offsets are arrangements that will allow us to compensate for our own greenhouse gas emissions by investing in a greenhouse gas reduction or sequestration project somewhere else. These arrangements can take many forms, from forest conservation to renewable energy development to landfill methane capture.” (CEAC report)

At the end of the school year, CEAC generated a report that recommended principles for carbon offset purchases for 2020 and in the near future and also urged the College to reduce its dependency on offsets.

“Offsets are a short-term solution to our carbon pollution problem. The only question is how short-term. As it develops its offsets portfolio, we urge the College to explicitly factor offsets into its long-term strategic planning, and to maintain an ongoing public dialogue about the time horizon of its offset investments. In the meantime, we should be on guard for any signs of moral licensing, especially when it comes to decisions with long-term implications for campus energy use.”
– Campus Environmental Advisory Committee (CEAC) report

Below you will find:

  1. CEAC’s specific recommendations
  2. The purchase made in the fall of 2020 to offset FY20 emissions.
  3. Information about the trial-run purchase that was made in September 2019
  4. Student projects focused on carbon offsets

A link to the full carbon offsets report can be found here.


I. Recommendations from the CEAC Report:

Our recommendation: The college’s stated commitment requires the purchase of carbon offsets, at least in the short term, to meet our goal of achieving carbon neutrality by 2020. Carbon offsets have the potential to generate meaningful reductions in the college’s carbon footprint without compromising its commitment to directly reducing emissions. The following recommendations are specific ways to ensure that the college’s purchase of carbon offsets yields real emissions reductions and supports the college’s broader goals. These recommendations also reflect discussions of the Campus Environmental Advisory Committee (CEAC). 

  1. Mission-linked offsets      We are hopeful that our choice to buy offsets can be used not just to balance our carbon budget, but also to encourage the kind of critical, self-reflective inquiry that is at the heart of our educational mission. To that end, we urge the College to prioritize offsets that satisfy two criteria: visibility and depth. Visibility: For offsets to be educationally valuable, they must be visible.  For offsets to be truly visible to the College community, they should be open to in-depth analysis, and that analysis should be actively promoted as a meaningful learning opportunity. Depth: For offsets to support the College’s educational mission, they should enable critical environmental thinking.
  2. Local Offsets      We believe that Williams should pursue opportunities to work on projects to reduce and sequester GHG emissions in the local community, but only if they meet the most rigorous standards of additionality, reasonably cost-effective carbon emissions reduction, and our standard of educational depth. In practice, this makes local offsetting very difficult, which is why we urge the College to also think about ways to support local mitigation efforts in different ways.
  3. Forest Management & Conservation       While lands that will remain forested regardless do not contribute additionality, lands that have been harvested for timber historically might well be considered to be legitimate candidates to qualify for carbon-sequestration offset production. However, they should be managed in a fashion that guarantees the annual carbon removal of wood from the site is less than the annual addition of carbon to the standing woody biomass and the annual addition of carbon to the soil is more than the annual respiratory loss of soil organic matter through decomposition.
  4. Educational Frameworks      We encourage the College to prioritize projects that (a) rely on science and technology that students can be reasonably expected to understand; (b) have proven, transparent track records; and (c) clearly illustrate the interconnectedness of economic, social, political, and natural systems.
  5. Co-Benefits      We encourage the College to prioritize the co-benefits of social engagement, equity, environmental health and conservation—all of which respond to what has clearly become the preeminent concern of our faculty and students, climate justice.
  6. Climate Justice      Williams has a responsibility to educate its students about the environmental justice implications of carbon offsets and a duty to avoid any offsetting schemes that might have any negative social consequences.  We believe that Williams should approach all offsets in the Global South with caution, recognizing that even the most apparently benign schemes involve asymmetrical power relations.
  7. Oversight       To minimize risk, the College should invest in a portfolio of offsetting projects that meets all of the criteria described above and affords students and faculty multiple opportunities for multi-disciplinary inquiry. We recommend the establishment of an offsets task force that meets at least twice per semester, consisting of the director of the Zilkha Center, the chair of Environmental Studies, one student, and two additional faculty members. Because the learning curve is steep, members of this group should serve multi-year terms.
  8. Offset vendors and institutional partnerships      We encourage the College to consider working with an organization that specializes in providing additional layers of scrutiny to verified projects, especially with respect to the extremely important question of additionality.

II. The Fall 2020 Purchase to Offset FY20 Emissions

The Carbon Offsets Working Group spent the spring and summer examining the monitoring and verification documents for each project and engaged in discussions about a potential portfolio of projects with a third-party aggregator – Cool Effect – through whom we are purchasing the offsets.*

Based on the group’s research, we have made the following recommendations  for the purchase of carbon offsets for FY20. Working group members wrote short reports articulating the rationale for each project that we have chosen to support and those we considered but ultimately decided against supporting. The process and rationale is written about more detail in this report published in Fall 2020.

* To learn more more about Cool Effect and their process, visit their website.

Carbon offset project recommendations and the percentage of the total purchase dedicated to each project.  More information can be found here.

Project Country $/tonne weighting
Mirador Clean Cookstoves Honduras $8.50 40%
Biogas Digesters & Clean Cookstoves China $5.02 25%
Solar DC Project India $4.94 25%
Turning Pig Waste Into Compost Brazil $7.22 10%

III. Carbon Offsets Working Group membership

Olamide Adeyeri, Class of 2023
Hank Art, the Environmental Studies Program, Rosenburg Professor of Environmental Studies and Biology, Emeritus
Ralph Bradburd, David A. Wells Professor of Political Economy
Mike Evans, Zilkha Center for Environmental Initiatives (chair)
Sarah Gardner, Associate Director and Lecturer in Environmental Studies
Nicolas Howe, Director of CES and the Environmental Studies Program, Associate Professor of Environmental Studies
Luana Majora, Associate Professor of Biology
Bless Reece, Class of 2022
Shawn Rosenheim, Professor of English, Chair of Campus Environmental Advisory Committee
Chris Winters, Associate Provost


IV. Offsets in the Trial-Run Purchase

The college made a trial-run purchase in September 2019 in order to give our community an opportunity to research the projects that we invested in and to learn more about the offset market in order to inform our next round of purchasing.  The initial round was for approximately 10% of our total carbon offset purchase that was made in November 2020.  The projects that we supported during this trial run period were:  the Tri-City Forest Project, Biogas Digesters for Farmers, and Mirador Clean Cookstoves


V. Student Projects Focused on Carbon Offsets

Offsets have been incorporated into a number of courses including as the focal point of Professor Ralph Bradburd’s “The Economics and Ethics of CO2 Offsets.”  Here are a few Williams students papers focusing on offsets.

Carbon Offsets: Potential Biodiversity Impacts and Recommendations

By Adrienne Banks, Liam Bardong, Shauna Sullivan, Sean Dory, Astrid DuBois, Emily Elder, Rebecca Smith, and Laura Martin
Envi 252: Biodiversity and Climate Change, Spring 2018

Restorative climate justice and carbon offsetting: a theoretical analysis of climate justice and the moral value of carbon offsetting as a means towards that end

By Nick Gardner
Envi 412: Senior Seminar: Perspectives on Environmental Studies, Spring 2019

Carbon Neutrality at Williams: Should We Worry About Moral Licensing?
By Josie Maynard
Envi 412: Senior Seminar: Perspectives on Environmental Studies, Spring 2019