Scope 3 Emissions

2025 Emissions: 34,739 MTCO₂e | 14.2% of Scope 3

What is included?

This category includes emissions associated with the goods and services CU Boulder purchases to support university operations, teaching and research. Major sources include professional and support services, information technology, laboratory supplies and equipment, and facilities-related purchasing.

In 2025, the inventory covered approximately $305 million in purchasing activity. Professional services, IT, laboratories and facilities accounted for more than 80% of the estimated emissions in this category.

How emissions are calculated

CU Boulder uses a spend-based methodology that assigns emissions factors to purchasing transactions based on the type of product or service purchased. The updated inventory applies 295 industry-specific emissions factors using the U.S. Environmentally Extended Input-Output (USEEIO) model and North American Industry Classification System (NAICS) codes.

This represents a substantial improvement over the original Climate Action Plan inventory, which used a limited sample of transactions and a small number of emissions factors.

Data Considerations

Although the updated methodology captures approximately five times more spending than the original CAP analysis, the estimates remain dependent on spending classifications and industry-average emissions factors. Purchasing Card (P Card) and Travel Card (T Card) transactions are not yet fully included.

Spend-based estimates also do not necessarily reflect the emissions benefits of choosing lower-carbon products or suppliers, particularly when those alternatives cost more.

Reduction Goals & Strategies

The Scope 3 Working Group is exploring proposed opportunities to reduce purchasing-related emissions through reuse, circularity and supplier engagement. Because spend-based emissions estimates do not always reflect the environmental benefits of purchasing decisions, the proposed approach focuses on measurable improvements beyond GHG accounting.

Proposed strategies and performance targets include:

• Expand reuse and circularity: Increase the volume of materials and equipment reused by 10%, including through Green Labs and move-in/move-out reuse programs.
• Strengthen supplier engagement: Work toward having suppliers representing at least 10% of university purchasing expenditures maintain internal sustainability programs.
• Improve purchasing data: Expand inventory coverage to include P Card and T Card transactions and strengthen purchasing classifications to better inform supplier engagement and procurement decisions.

What is included?

Food emissions come from the production and supply of food purchased for CU Boulder dining and catering operations. These emissions vary significantly by food type, with animal-based products generally having higher GHG emissions per kilogram than plant-based foods.

The 2025 analysis identified beef as one of the largest contributors to food-related emissions, despite representing a relatively small portion of food purchased by weight.

How emissions are calculated

CU Boulder uses a quantity-based methodology, applying food-specific emissions factors to the weight of purchased food. These factors account for differences in the GHG emissions associated with producing various foods, including meat, dairy, grains, fruits and vegetables.

This approach replaces the original CAP methodology, which estimated all food and beverage emissions using a single spend-based factor.

Data Considerations

Food purchasing data provide a relatively detailed basis for estimating emissions, allowing the university to examine changes in purchasing patterns and the GHG intensity of different foods.

Emissions estimates depend on the food categories and industry-average factors applied and may not capture every difference in individual suppliers' production practices.

Reduction Goals & Strategies

In 2026, the Sustainability Council proposed a goal to reduce food-related GHG emissions 25% by 2035 from the recalculated 2019 baseline. Because food emissions can be estimated using actual purchasing quantities and food-specific emissions factors, the university can track changes associated with purchasing decisions.

Proposed strategies include:

• Reduce food waste: Prevent unnecessary food purchases and associated emissions through waste reduction efforts.
• Reduce high-emissions food purchases: Decrease the quantity of beef and lamb purchased, which have relatively high GHG emissions compared with many other foods.
• Expand food recovery: Build on food recovery initiatives to make better use of existing food and reduce the need for additional purchases.

What is included?

This category estimates indirect emissions associated with CU Boulder's use of cloud-based computing and artificial intelligence services. These technologies rely on data centers and computing infrastructure that consume electricity and, in some cases, significant water resources.

As the university's use of cloud computing and AI expands, understanding the environmental impacts of these services is an emerging area of Scope 3 analysis.

How emissions are calculated

The working inventory estimates AI-related energy consumption using available university usage data and assumptions about activity occurring outside centrally managed platforms.

Estimated activity is combined with energy-use factors for different types of AI tasks, including text, image and video generation. An electricity emissions factor is then applied to estimate GHG emissions.

Data Considerations

This is an emerging category with substantial uncertainty. CU Boulder does not currently have comprehensive information about all AI and cloud computing activity across university-managed and personal accounts.

Energy use also varies significantly depending on the type of task, computing infrastructure and electricity source. Estimates will continue to evolve as additional usage information and provider-specific data become available.

Reduction Goals & Strategies

CU Boulder's proposed approach focuses on improving transparency and supplier environmental performance rather than establishing a numerical GHG reduction target. As AI and cloud computing usage expands, better information about data center operations will help the university understand and influence associated emissions. The Scope 3 Working Group will help examine the proposed strategies below.

Proposed strategies include:

• Improve environmental reporting: Engage technology providers to obtain information on data center energy consumption, water use and GHG emissions.
• Strengthen supplier expectations: Explore environmental reporting requirements in contracts with cloud computing and AI providers.
• Support cleaner electricity: Evaluate opportunities to work with providers that support lower-carbon electricity and avoid new behind-the-meter natural gas generation for data centers.

2025 Emissions: 13,268 MTCO₂e | 5.4% of Scope 3

What is included?

Construction emissions are primarily associated with the production of building materials and other activities involved in constructing and renovating campus facilities. These emissions, often referred to as embodied carbon, occur before a building begins operating and are separate from the energy used to heat and power it.

Materials such as concrete and steel can be significant contributors to embodied carbon.

How emissions are calculated

CU Boulder's updated inventory estimates construction emissions using information from completed campus projects.

For projects with available building square footage, emissions are calculated using project-type-specific factors informed by the Carbon Leadership Forum. When square footage is unavailable, the university applies spend-based emissions factors to project expenditures.

Emissions are assigned to the fiscal year in which a project is completed.

Data Considerations

The updated approach provides a more detailed estimate than the original CAP methodology, which relied on assumed annual growth in building square footage.

However, project-level estimates may not capture the actual materials and construction practices used. Whole Building Life Cycle Assessments (WBLCA) can provide more detailed information about embodied carbon for individual construction and major renovation projects.

Reduction Goals & Strategies

CU Boulder is evaluating project-level goals to reduce embodied carbon in new construction and major renovations. The proposed approach focuses on improving material selection, encouraging building reuse and incorporating more detailed emissions assessments into campus construction projects.

Proposed targets and strategies include:

• Reduce embodied carbon in new construction: Target at least a 5% reduction relative to applicable LEED v4 or v5 benchmarks.
• Prioritize building reuse: Target 60–70% lower embodied carbon for major renovations compared with equivalent new construction through building reuse.
• Conduct lifecycle assessments: Use Whole Building Life Cycle Assessments (WBLCA) to evaluate embodied carbon in new construction and major renovation projects.
• Explore lower-carbon materials: Evaluate opportunities to use mass timber and other materials with lower embodied carbon, including consideration of biogenic carbon storage.
• Engage the construction industry: Explore purchasing partnerships and industry initiatives that support lower-carbon steel and cement production.

2025 Emissions: 509 MTCO₂e | 0.2% of Scope 3

What is included?

This category captures the embodied emissions associated with manufacturing vehicles purchased by CU Boulder, including buses, trucks, vans, passenger vehicles and other fleet equipment.

These emissions are distinct from Scope 1 emissions generated when university-owned vehicles burn fuel during operation.

How emissions are calculated

CU Boulder estimates vehicle manufacturing emissions using the number and type of vehicles acquired, their powertrain technologies and associated lifecycle emissions factors.

The updated methodology applies different emissions factors for vehicle types and powertrains, including gasoline, diesel, hybrid and battery-electric vehicles. This replaces the original CAP approach, which relied on broad powertrain factors and assumptions about vehicle useful life.

Data Considerations

Vehicle acquisition records provide relatively reliable information about the types and numbers of vehicles purchased.

Battery-electric vehicles can have higher manufacturing emissions than comparable conventional vehicles, particularly due to battery production. However, this category does not capture the potential operational emissions savings achieved through fleet electrification.

Reduction Goals & Strategies

CU Boulder has not proposed a specific GHG reduction target for emissions associated with manufacturing purchased vehicles. The university's primary fleet decarbonization priority is reducing operational emissions through electrification, while also considering the embodied emissions of new vehicle purchases.

Proposed strategies include:

• Track vehicle manufacturing emissions: Continue measuring embodied carbon associated with new vehicle purchases by vehicle type and powertrain.
• Encourage vehicle sharing: Improve fleet utilization and reduce unnecessary vehicle purchases through shared-use opportunities.
• Coordinate fleet planning: Consider manufacturing emissions alongside operational emissions as CU Boulder continues transitioning its vehicle fleet toward electric alternatives.

What is included?

Fuel- and energy-related activities capture GHG emissions associated with producing and delivering the fuels and electricity CU Boulder consumes, beyond the direct emissions already reported in Scope 1 and Scope 2.

These include emissions from natural gas extraction, processing and transportation; production of vehicle fuels; and upstream electricity generation activities and transmission and distribution losses.

Methane leakage associated with natural gas production and distribution is a particularly important source.

How emissions are calculated

CU Boulder calculates FERA emissions using its Scope 1 and Scope 2 energy consumption data, combined with emissions factors for upstream fuel production, electricity generation and transmission and distribution.

The updated inventory uses U.S. and Colorado-relevant factors from sources including SIMAP and Xcel Energy, replacing the United Kingdom-based factors used in the original CAP.

Data Considerations

The updated methodology produces significantly higher estimates than the original CAP inventory, primarily because of differences in emissions factors and treatment of upstream natural gas emissions.

These changes reflect improved accounting rather than a corresponding increase in fuel consumption.

Reduction Goals & Strategies

CU Boulder is evaluating a goal to reduce FERA emissions 100% by 2050, consistent with the university's long-term Scope 1 and Scope 2 decarbonization goals.

Because these emissions are associated with the production and delivery of fuels and electricity consumed by CU Boulder, reductions are closely tied to changes in campus energy use and the regional electricity supply.

Proposed strategies include:

• Reduce upstream fuel emissions: Decrease natural gas and other fossil fuel consumption through building efficiency, heating system decarbonization and fleet electrification.
• Reduce upstream electricity emissions: Benefit from continued grid decarbonization and expanded renewable electricity.
• Track energy-related reductions: Use annually updated Scope 1 and Scope 2 energy data and upstream emissions factors to measure progress.

2025 Emissions: 1,747 MTCO₂e | 0.7% of Scope 3

What is included?

This category captures GHG emissions associated with waste generated through campus operations, including materials sent to landfills, recycling and composting facilities.

Different waste management methods produce different emissions. Landfilled organic materials, for example, can generate methane as they decompose.

How emissions are calculated

CU Boulder uses annual waste quantity and diversion data, applying emissions factors appropriate to each waste stream.

The updated methodology separates landfill, recycling, composting and reuse rather than treating multiple waste streams as landfill, as occurred in the original CAP estimate.

Data Considerations

CU Boulder has relatively strong information about overall campus waste generation and diversion. However, emissions estimates depend on the types of materials being managed, treatment processes and associated emissions factors.

Improvements in waste accounting have contributed to changes in the estimated emissions compared to the original CAP.

Reduction Goals & Strategies

CU Boulder is evaluating a goal to increase waste reuse and diversion to 75% by 2030, which is estimated to produce approximately a 20% reduction in waste-related GHG emissions. The updated Scope 3 assessment also proposes a longer-term goal of reducing waste emissions 40% by 2050.

Proposed strategies include:

• Expand reusable food service products: Increase the use of reusable dining and café to-go containers to prevent waste generation.
• Improve composting: Reintroduce front-of-house composting to divert organic materials from landfill disposal.
• Increase recycling participation: Improve recycling collection through consistent bin availability, placement and campus outreach.
• Strengthen waste prevention: Incorporate waste reduction into purchasing practices and expand education and engagement around reuse and diversion.

2025 Emissions: 20,807 MTCO₂e | 8.5% of Scope 3

What is included?

Business travel emissions are associated with university-related travel for conferences, research, professional activities and other university business.

Air travel is a major contributor, particularly longer-distance flights. The climate impacts of aviation include both carbon dioxide emissions and additional warming effects associated with aircraft operations at high altitudes.

How emissions are calculated

CU Boulder estimates business travel emissions primarily using travel records from the university's Concur system.

Air travel is categorized by flight distance, with different emissions factors applied to short-, medium- and long-haul flights. The inventory also applies an adjustment for aviation's additional warming impacts beyond direct carbon dioxide emissions.

This represents an improvement over the original CAP methodology, which applied a single medium-haul emissions factor to all flights.

Data Considerations

Concur provides relatively detailed travel records, but limitations remain. Some records may not clearly distinguish one-way from round-trip travel, and the working inventory does not yet include all athletics-related travel.

Reduction Goals & Strategies

CU Boulder has not proposed a specific GHG reduction target or formal reduction strategies for business travel. The university continues to evaluate opportunities to address emissions from this category as part of its broader Scope 3 planning efforts.

What is included?

This category captures travel associated with CU Boulder Education Abroad programs and international student-related travel tracked through International Student and Scholar Services (ISSS).

International air travel represents a substantial portion of these emissions due to the distances involved.

How emissions are calculated

CU Boulder estimates travel distances using program destinations, participant counts and available international student travel information. Emissions factors are applied based on transportation mode and travel distance.

Air travel estimates also include an adjustment for aviation's additional warming impacts.

Education abroad and ISSS travel were not separately quantified in the original CAP inventory.

Data Considerations

Available data generally identify program destinations and participant counts rather than detailed individual itineraries. Actual flight routes, connections and additional in-country travel may differ from the estimated travel patterns.

Reduction Goals & Strategies

CU Boulder has not proposed a specific GHG reduction target or formal reduction strategies for education abroad and international student-related travel. The university continues to evaluate opportunities to address emissions from this category as part of its broader Scope 3 planning efforts.

What is included?

Commuting emissions result from daily travel to and from CU Boulder by students, faculty and staff.

Emissions vary depending on commuting distances, frequency, transportation mode and vehicle type. Driving alone generally contributes more emissions per traveler than carpooling, public transportation, walking or biking.

How emissions are calculated

CU Boulder estimates commuting emissions using transportation survey data, student and employee population information and estimated vehicle miles traveled.

The methodology accounts for different travel modes, including driving alone, carpooling, transit, walking and biking, with appropriate emissions factors applied to motorized travel.

Data Considerations

Commuting estimates rely heavily on survey participation and assumptions about travel behavior. The 2025 analysis used a survey with responses from approximately 1% of the campus population, creating significant uncertainty when results are extrapolated to the broader university community.

Reduction Goals & Strategies

CU Boulder is evaluating a goal to reduce commuting-related GHG emissions 35% by 2035, with a longer-term proposed goal of reaching zero commuting emissions by 2050.

The proposed approach combines reductions in vehicle travel with the continued transition toward electric vehicles.

Proposed strategies include:

• Reduce vehicle miles traveled: Update transportation demand management programs with a proposed target of reducing commuting vehicle miles traveled by 10%.
• Encourage alternative transportation: Support public transit, biking, walking and carpooling to reduce reliance on single-occupancy vehicles.
• Support electric vehicle adoption: Expand campus charging infrastructure to accommodate the transition toward electric commuting vehicles.
• Improve commuting estimates: Strengthen survey participation and transportation data collection to better measure progress toward reduction goals.

What is included?

This category captures emissions associated with buildings and spaces CU Boulder leases from third parties when those emissions are not already included in its Scope 1 or Scope 2 inventory.

Examples include leased offices, research facilities, storage areas and other off-campus spaces.

How emissions are calculated

CU Boulder estimates energy consumption using leased building area and average electricity and natural gas consumption rates for different types of commercial buildings.

Emissions factors are then applied to estimate GHG emissions associated with the leased space.

The updated methodology includes additional building categories and more specific energy-use assumptions than the original CAP.

Data Considerations

The university has relatively reliable information about leased building area, but actual energy consumption is not available for every facility.

Estimates therefore rely on typical energy-use patterns rather than measured utility consumption for each leased location.

Reduction Goals & Strategies

CU Boulder has not proposed a specific GHG reduction target for leased facilities. The updated assessment identifies opportunities to reduce emissions by improving the energy performance of leased space and evaluating alternatives as campus facilities and leasing needs change.

Proposed strategies include:

• Prioritize efficient leased facilities: Look for opportunities to lease space in all-electric buildings as they become more widely available.
• Evaluate campus consolidation: Consider relocating off-campus leased activities into university-owned facilities over time where operationally feasible.

What is included?

Student and family travel is CU Boulder's largest estimated Scope 3 emissions source.

This category captures travel between students' home communities and campus, along with related family travel. It includes travel by domestic and international students and families, such as trips associated with academic breaks, moving to campus and campus visits.

These emissions are separate from daily employee and student commuting.

How emissions are calculated

CU Boulder estimates travel distances using student home-location information, geographic analysis and assumptions about the number of trips taken by different student populations.

The methodology differentiates travel by undergraduate, graduate and international students and includes family travel. Transportation modes are estimated based on distance, with emissions factors applied to vehicle and air travel.

Compared with the original CAP, the updated approach includes more detailed student-location data, in-state travel and longer international travel distances.

Data Considerations

This category has substantial uncertainty because actual individual travel activity is not comprehensively recorded. Estimates rely on assumptions about trip frequency, travel mode, vehicle occupancy and travel distances.

Although the improved methodology captures more university-related travel, the higher estimates primarily reflect expanded data coverage and revised assumptions rather than a documented increase in travel.

Reduction Goals & Strategies

CU Boulder has not proposed a specific GHG reduction target or formal reduction strategies for student and family travel. The university continues to evaluate opportunities to address emissions from this category as part of its broader Scope 3 planning efforts.