Scope 3 Emissions
Measuring and reducing emissions across CU Boulder’s value chain
Scope 3 emissions are indirect greenhouse gas emissions associated with CU Boulder activities, from the goods and food the university purchases, to the construction materials used in the buildings it constructs, every day commuting to and from campus, university travel, and waste.
Unlike Scope 1 and Scope 2 emissions, these emissions occur largely from sources that CU Boulder does not own or directly control. The university can, however, influence many of them through purchasing decisions, building and infrastructure standards, transportation programs, travel practices, contracts and partnerships.
Because Scope 3 emissions come from many different activities and data sources, they also vary significantly in how accurately they can be measured and how much the university can influence them. CU Boulder will continue to improve its Scope 3 inventory while developing specific strategies focused on areas where the university can create meaningful impact.
A Revised 2019 Scope 3 Baseline
The 2019 Scope 3 baseline included in CU Boulder’s 2024 Climate Action Plan was a first-generation estimate developed with the data and methodologies available at the time. The CAP Scope 3 analysis was intended to provide an initial, directional understanding of the university’s value-chain emissions.
Since then, CU Boulder has substantially improved the inventory, recalculating emissions using more complete data, more appropriate emissions factors and more detailed category-specific methodologies.
Improvements include:
- expanding purchased-goods analysis from a limited sample of transactions to the broader university purchasing dataset;
- using improved emissions factors for upstream fuel and energy activities (FERA) instead of the factors used in the original CAP;
- applying different emissions factors to landfill, recycling, composting and reuse rather than treating multiple waste streams as landfill;
- distinguishing short-, medium- and long-haul air travel;
- adding education abroad as a separately tracked source;
- incorporating updated commuting survey data;
- expanding leased-space data and building types; and
- improving student and family travel estimates to include in-state travel, international travel and more detailed student-location data.
For example, the updated purchasing methodology covers approximately five times the spending volume compared to the sample used for the CAP and applies nearly 300 spend-based emissions factors to different types of purchases rather than 5 in the CAP.
Importantly, a higher recalculated baseline does not mean CU Boulder generated more emissions in 2025. Rather, the updated inventory captures substantially more activity and applies more complete and accurate methodologies than the preliminary CAP inventory.
Continuous Improvement
Scope 3 accounting continues to evolve. CU Boulder relies on a wide range of university records, surveys, supplier information, industry data and emissions factors, and data quality differs significantly among categories.
CU Boulder will continue refining both historical and current inventories as university data, supplier information, emissions factors and accounting practices improve. When methodologies change materially, the university may update historical estimates so progress can be evaluated consistently over time.
[Explore Scope 3 Inventory Methodology (coming soon)]
What CU Boulder Includes in Its Scope 3 Inventory
The Greenhouse Gas Protocol identifies 15 categories of Scope 3 emissions. Not every category is applicable to a university.
CU Boulder currently quantifies the Scope 3 sources that are relevant to campus operations and for which a reasonable accounting methodology can be established. The university also separately evaluates several higher-education-specific sources, including education abroad and student and family travel, that are important to understanding its broader emissions footprint.
For several categories, CU Boulder uses additional subcategories to better distinguish major sources. For example, Category 1 is separated into purchasing, food, and cloud computing and AI, while university travel is separated into business travel and education abroad.
GHG Protocol Category | CU Boulder Treatment | Why |
|---|---|---|
1. Purchased goods and services | Included | Includes goods and services purchased by the university. CU Boulder further separates this category into 1a: Purchasing (Spend-Based), 1b: Food, and 1c: Cloud Computing and AI because these sources use different data and methodologies. Current purchasing estimates do not yet include all P Card and T Card spending. |
2. Capital goods | Included | Includes 2a: Construction and 2b: Purchased Vehicles. CU Boulder makes decisions about buildings, renovations and vehicle purchases and can influence embodied emissions through design, procurement and reuse. |
3. Fuel- and energy-related activities | Included | Captures upstream emissions associated with the production and delivery of fuels and electricity used by CU Boulder, including methane leakage and transmission and distribution losses. These emissions are closely tied to the university’s Scope 1 and Scope 2 energy use. |
4. Upstream transportation and distribution | Accounted for within purchasing; not shown as a separate line item | Includes transportation and delivery of goods purchased by CU Boulder. The current inventory incorporates these impacts within purchasing rather than reporting a separate Category 4 total. |
5. Waste generated in operations | Included | Includes landfill, recycling and composting. CU Boulder has relatively strong waste-stream data and can influence these emissions through waste prevention, reuse, composting, and recycling. |
6. Business travel | Included | CU Boulder separates university travel into 6a: Business Travel and 6b: Education Abroad for internal analysis. Education abroad is tracked separately because it is a significant university-related travel source with different activities and decision-making considerations. |
7. Employee commuting | Included, with student commuting also evaluated | Includes regular employee and student travel to and from campus. CU Boulder can influence commuting through transportation demand management, transit, biking and walking infrastructure, housing and electric-vehicle charging, although estimates rely partly on survey data. |
8. Upstream leased assets | Included | Includes emissions associated with buildings, laboratories and office space CU Boulder leases from third parties when those emissions are not already included in Scopes 1 or 2. |
9. Downstream transportation and distribution | Included, by tracking student and family travel to and from campus | The traditional GHG Protocol category primarily applies to downstream transportation of sold products. For its higher-education inventory, CU Boulder uses this portion of the inventory to estimate student and family travel between home communities and campus, a significant university-related source. |
10. Processing of sold products | Not applicable | CU Boulder does not manufacture products that require downstream processing. |
11. Use of sold products | Not applicable to the inventory | Education and research create broad impacts, but those outcomes cannot reasonably be treated or quantified as the downstream “use of sold products” for greenhouse gas accounting. |
12. End-of-life treatment of sold products | Not applicable | CU Boulder does not manufacture and sell products for which downstream end-of-life emissions would be attributed to the university. |
13. Downstream leased assets | Not applicable under the current inventory boundary | CU Boulder does not have material buildings leased to outside organizations that qualify for reporting in this category under the university’s inventory boundary. |
14. Franchises | Not applicable | CU Boulder does not operate a franchise business model. |
15. Investments | Under review | University investments are managed at the CU System level. The 2024 CAP included an initial estimate for a portion of investment-related emissions, but additional analysis and coordination are needed before this category is incorporated into the updated campus inventory. |
CU Boulder’s Scope 3 Approach to Goal Setting
CU Boulder’s 2024 Climate Action Plan established a goal to reduce Scope 3 emissions where accurate estimates could be developed and where the university has meaningful influence or control.
Since adoption of the plan, CU Boulder has conducted a more detailed assessment of individual Scope 3 sources, considering:
- the size of each emissions source;
- the quality and availability of the underlying data;
- CU Boulder’s ability to influence or control the source;
- opportunities to achieve measurable greenhouse gas reductions;
- broader benefits such as health, mobility, equity, waste reduction and resilience; and
- potential effects on the university’s education and research mission.
This analysis showed that a single reduction target is not equally meaningful or achievable across all Scope 3 sources. Some categories, such as food, upstream fuel- and energy-related activities (FERA), and waste, can be measured and influenced relatively directly. Others depend heavily on individual behavior, suppliers behavior, or broader industry action such as through decarbonized cement or aviation.
Based on this, CU Boulder uses category-specific greenhouse gas targets where emissions can be measured reliably and the university has meaningful ability to influence them, and other performance metrics where direct emissions reductions are more difficult to measure or control.
Understanding CU Boulder’s Scope 3 Footprint
CU Boulder’s latest 2025 inventory estimates approximately 245,074 MTCO₂e of Scope 3 emissions, representing about 70% of the university’s measured Scope 1, Scope 2 and Scope 3 greenhouse gas footprint.
The largest estimated sources are:
- Category 9: Student and family travel to and from campus: approximately 31%
- Category 3: Fuel- and energy-related activities: approximately 19.5%
- Category 1a: Purchasing: approximately 14.2%
- Category 6a: Business travel: approximately 8.5%
- Category 6b: Education abroad: approximately 8.3%
- Category 7: Employee and student commuting: approximately 7.4%
- Category 2a: Construction: approximately 5.4%
- Category 1b: Food: approximately 4.8%
Together, these eight sources account for approximately 99% of CU Boulder’s measured Scope 3 emissions. Waste, upstream leased assets, purchased vehicles, and cloud computing and AI make up the remaining approximately 1%.
How CU Boulder Is Addressing Scope 3 Emissions
CU Boulder prioritizes Scope 3 action based not only on the size of an emissions source, but also on how accurately it can be measured, how much influence or control the university has over it, and where action can create meaningful real-world impact.
Because Scope 3 categories vary widely in data quality and controllability, they require different approaches. Categories with stronger data and greater university influence can support measurable greenhouse gas reduction targets. For categories where emissions are more difficult to measure or depend heavily on individual behavior, suppliers or broader industries, CU Boulder may instead focus on operational improvements, engagement, or other performance measures.
Different Scope 3 sources therefore require different approaches. Some categories have quantitative greenhouse gas reduction targets, while others use operational or performance metrics that better reflect what CU Boulder can meaningfully influence.
CU Boulder’s Theory of Change
CU Boulder uses the following principles to guide and prioritize Scope 3 strategies:
- Maximize global environmental impact. Prioritize actions that reduce CU Boulder’s greenhouse gas emissions and can also help catalyze broader emissions reductions beyond campus.
- Deliver meaningful co-benefits. Favor strategies that, alongside reducing emissions, improve health, equity, mobility and resilience for the CU Boulder community and, where possible, contribute to benefits at the state, national or global level.
- Support CU Boulder’s mission. Evaluate whether climate actions strengthen or detract from the university’s ability to provide high-quality education and research, and prioritize approaches that advance climate goals while supporting the academic mission.
- Focus on real-world impact. Prioritize actions that produce meaningful emissions reductions or other demonstrated climate benefits rather than measures intended primarily to reduce reported emissions through accounting mechanisms or actions without evidence of net emissions improvement.
Together, these considerations help CU Boulder determine where quantitative greenhouse gas reduction targets are appropriate and where other strategies or performance metrics provide a more meaningful measure of progress.