Measuring Our Emissions
Scope 1 & 2 Emissions
Stanford’s remaining Scope 1 and 2 greenhouse gas inventory emissions come from fuel combustion in buildings and vehicles, fugitive chemical and gas releases, and research processes. For over two decades, Stanford has measured, planned, and invested in systems and operational improvements to reduce these emissions. The university’s 2011 baseline inventory reported approximately 202,000 MTCO2e, and was the first complete emissions inventory reported to The Climate Registry.
Despite significant growth in campus building area and population, Stanford has reduced its Scope 1 and 2 emissions by more than 80% from 2011 levels as of 2023. The inventory includes roughly 800 buildings encompassing over 20 million square feet. Stanford owns and operates district-level energy facilities at both the main and Redwood City campuses, along with thousands more individual gas and electric utility meters directly connected to buildings.
The remaining emissions, primarily from district-level and building-level stationary combustion and hydrofluorocarbons, require robust planning, investment, data collection, and analysis tools. Addressing these sources depends on new capital investments and coordinated action across multiple departments.
Scope 1 & 2 Emissions Categories & Reporting Methodologies
Stanford measures and verifies its Scope 1 and 2 emissions annually by applying emission factors to data from utilities, fuel use, research gases and refrigerants. A third-party verifier confirms these calculations under The Climate Registry General Reporting Protocol, which ensures accuracy and consistency across all reported scopes. Stanford’s Scope 1 and 2 inventory includes all university-owned and operated buildings and assets in North America and accounts for all seven gases identified by the Kyoto Protocol: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride. Boundaries between Scope 1 and 2 versus scope 3 are carefully defined to prevent overlap or omission. For Scope 1 and 2 emissions, Stanford uses the Global Warming Potential standard consistent with the latest Intergovernmental Panel on Climate Change report for each emission year.
Stationary Combustion
Definition: Stationary combustion includes emissions from on-site fossil fuel combustion from the equipment owned or operated by Stanford that remains in a fixed location, such as gas boilers, hot water generators, diesel-powered emergency backup generators, steam generators, and gas stoves. This may include equipment in buildings that are fully owned or leased by Stanford.
Data: Most stationary combustion data comes from metered utility data and internal sub-metered reports. The small amount of remaining emissions primarily come from emergency diesel generators.
Calculating Emissions: Utility and sub-metered energy data are typically reported in natural gas therms, which are converted to equivalent emissions based on a prorated calendar year. A small amount of purchased steam is converted to natural gas equivalents before calculating emissions. Emissions from emergency diesel generators are estimated using hourly runtime data. Emissions factors for all stationary combustion sources follow The Climate Registry and Intergovernmental Panel on Climate Change protocols and tend to remain relatively consistent over time.
Purchased Electricity
Definition: Purchased electricity emissions occur off-site from electricity purchased from utility providers. At Stanford, this electricity is used to power equipment at facilities owned and operated by the university.
Data: Most of Stanford’s purchased electricity data are obtained directly from utility and internal sub-meters. For a small portion of some leased space, about 1% of total building area, where metered utility data is unavailable, emissions are estimated based on square footage and building use types.
Calculating Emissions: Utility and sub-metered energy data are typically reported in kilowatt hours, which are converted to equivalent emissions based on a prorated calendar year. Purchased electricity emissions are calculated using the market-based method, which takes into account the impacts renewable electricity procurement has on reducing calculated emissions. Calculated purchased electricity emissions have been zero since calendar 2023 with Stanford sourcing 100% renewable electricity. Learn more at Stanford’s renewable energy site.
Purchased Heating
Definition: Purchased heating emissions occur off-site from heating purchased from utility providers. At Stanford, these are emissions from the equivalent natural gas therms used in a small number of buildings that the university leases from others where metered natural gas data is unavailable.
Data: Square footage, lease term dates, and building usage types data are collected from lease agreements.
Calculating Emissions:Leased building emissions are conservatively estimated using Energy Information Administration (EIA) utility benchmarks and regional emissions factors. The leased square footage is prorated by months of occupancy, multiplied by EIA natural gas usage averages for the building’s region and type, and then converted from cubic feet to therms to calculate equivalent emissions.
Future Improvements: Securing direct utility or emissions data for all leased assets and moving away from square- footage based estimates is an important step towards more accurate emissions reporting.
Fugitive
Definition: Fugitive emissions are from chemicals or gases from the operation or maintenance used in on-site equipment owned by Stanford. These are primarily emissions from HVAC units, chillers, refrigerators, and freezers, as well as laboratory research.
Data: District-level chiller refrigerant data is collected directly from meters displaying the pounds of gas in the equipment, while most research gas usage is collected by weighing research gas tanks. Refrigerant data from equipment like HVAC units, refrigerators, freezers, and fire suppression systems in some server rooms, as well as a small amount of research gases, are based on spend-data.
Calculating Emissions: District-level chiller refrigerant and most research gas emissions are calculated by applying emissions factors to the pounds of refrigerant serviced or leaked or gas used. A hybrid approach is used for remaining spend-based calculations. When available, spend-based data is analyzed to determine the pounds and type of refrigerant or research gas purchased for emission calculations. When the pounds or refrigerant type are unavailable for equipment, comparable equipment of a similar type and size is identified to determine the likely refrigerant pounds and type. That data is then used to conservatively estimate annual refrigerant leak rates and calculated emissions by applying The Climate Registry default factors for the equipment type.
Mobile Combustion
Definition: Mobile combustion emissions are from on-site fossil fuel combustion from equipment owned or operated by Stanford that may move, such as gasoline or diesel-powered vehicles, trucks, and buses.
Data: Most mobile combustion data comes directly from metered gasoline and diesel data reports of fuel used by Stanford- owned fleet vehicles at a fueling station on the Stanford campus. Gallons of renewable diesel used in several emergency-backup Marguerite fleet buses are tracked through vendor reports. Less than 8% of mobile emissions is also calculated from gasoline and diesel fuel purchases at gas stations using department or personal credit cards where gallons of fuel metrics are unavailable. Emissions factors applied to mobile combustion data are sourced from The Climate Registry and/ or IPCC.
Calculating Emissions: Over half of the owned-vehicles at Stanford are now electric and charged on campus, which generate zero emissions. For the remaining fossil fuel powered vehicles, a hybrid approach utilizes direct gallons of fuel data when available and emissions are calculated using emissions factors that are specific to the fuel type, such as gasoline, diesel, or biodiesel. When direct fuel data is unavailable, Stanford estimates emissions by applying spend-based data to calculate emissions.
Process
Definition: Process emissions are from on-site chemicals or processes that are not used in industrial equipment. At Stanford, these are emissions from the use of laboratory research chemicals and gases.
Data: Most research gas information is based on data collected from weighing research gas tanks. A small amount of remaining emissions is calculated from spend-data on research gases.
Calculating Emissions: Most research gas emissions are calculated by applying an emissions factor to the pounds of gas used based on the specific gas type. Spend-based data is analyzed to collect the pounds and type of research gas purchased to calculate the emissions.
Scope 3 Emissions
Stanford has made meaningful progress in measuring and reducing Scope 3 emissions by developing methodologies across eight key emissions categories, integrating emissions considerations into procurement, travel, and construction decisions, and launching targeted initiatives in areas like business travel and commuting to drive reductions. Through cross-campus collaboration and ongoing improvements in data collection and reporting, Stanford has emerged as a leader in Scope 3 management and is committed to advancing scalable, transparent approaches that support broader climate action across higher education.
Why Scope 3 Matters
While Scope 1 and 2 emissions—from direct fuel use and purchased electricity—are relatively straightforward to measure and mitigate, Scope 3 emissions capture the broader and often less visible impact of university operations. These include the carbon footprints of purchased goods and services, commuting, travel, construction, leased assets, and more. At Stanford, Scope 3 emissions represent the largest share of our total greenhouse gas footprint.
Recognizing this, Stanford launched a comprehensive Scope 3 Emissions Program in 2021, following the Board of Trustees’ 2020 resolution to reach net zero greenhouse gas emissions in operations and endowment by 2050. Stanford aims to create a robust, transparent, and scalable approach for tracking and reducing Scope 3 emissions. In addition to reducing our own footprint, Stanford is committed to developing a framework that other institutions can follow, strengthening collective action on climate.
Getting Started
The Scope 3 program began with a screening and prioritization effort based on the GHG Protocol Corporate Value Chain (Scope 3) Standard. A working group composed of faculty, staff, students, and sustainability professionals led the process of identifying and addressing relevant emissions categories.
The team undertook the following steps:
- Reviewed all 15 Scope 3 categories defined by the GHG Protocol and identified emissions sources relevant to higher education
- Assessed each category based on its emissions potential, relevance to Stanford operations, data availability, and potential for influence or mitigation
- Developed a “waterfall” approach, where categories are addressed in phases, reflecting resource availability and methodological complexity
- Began work on selected categories (e.g., business travel, commuting, purchased goods) while preparing others for future inclusion
For each category, the following framework is applied:
- Define the emissions source and operational boundaries
- Adopt or develop a methodology for calculating emissions
- Collect relevant data, using best-available records or estimates
- Report results annually, tracking progress over time
- Identify and implement mitigation strategies, engaging both internal departments and the broader campus community
This phased, iterative approach allows Stanford to balance rigor and practicality while aligning emissions accounting with institutional values and academic collaboration. It also provides opportunities for student and faculty engagement, especially where new methodologies or behavioral interventions are needed.
Scope 3 Emissions Categories & Reporting Methodologies
Stanford is committed to using the best available data and methodologies to calculate Scope 3 emissions across all relevant categories. Recognizing that data quality and emissions accounting practices are evolving rapidly, current methodologies are living frameworks that improve over time. As new research emerges, institutional systems mature, and better data becomes available, approaches are refined to ensure increasing accuracy and transparency. This website is updated regularly to reflect methodological changes and updated emissions factors.
Purchased Goods and Services
Definition: Purchased Goods and Services includes emissions from upstream production of goods and services procured by Stanford to support its operations. It includes Capital Goods unrelated to construction. Taxes, permit fees, donations, employee benefits, student aid and more are excluded.
Data: The Responsible Purchasing team in Procurement Services utilizes a spend intelligence platform that categorizes transactions from across the university into distinct spend categories. Transaction-level data including supplier name, spend amounts, purchase order descriptions, and more are pulled by spend category from this system, which enables streamlined application of emissions factors.
Data: The Responsible Purchasing team in Procurement Services utilizes a spend intelligence platform that categorizes transactions from across the university into distinct spend categories. Transaction-level data including supplier name, spend amounts, purchase order descriptions, and more are pulled by spend category from this system, which enables streamlined application of emissions factors.
Calculating Emissions: Stanford uses a hybrid approach incorporating supplier-specific, product-specific, and spend-based emissions factors. Supplier-specific and product-specific emissions factors are generated based on data submitted to Stanford from key suppliers on an annual basis; in some cases, these are also found in publicly available reports and databases. These highly accurate emissions factors are applied to the greatest extent possible, and spend-based factors are applied to the remaining items.
Future Improvements: Stanford’s database of supplier-specific and product-specific emissions factors grows every year, improving the footprint’s accuracy, and reflecting real-time decarbonization efforts among suppliers. Additionally, Stanford continues to grow its relationships with key vendors that may be able to provide Stanford-specific carbon emissions reports about Stanford’s purchases. Contact responsiblepurchasing@stanford.edu for more information or to receive a detailed white paper about this methodology.
Visit our shared methodology, developed in collaboration with sustainability teams at MIT, Harvard, and Yale, to help prioritize key Scope 3 emission categories to calculate and mitigate within Purchased Goods and Services.
Construction
Definition: Construction includes embodied emissions from materials and processes used in new buildings, major renovations, and infrastructure projects across Stanford’s campuses.
Data: Data is collected from project spend for small projects and whole building life cycle assessments (WBLCA) for large projects.
Calculating Emissions: A hybrid approach incorporates WBLCA outputs and spend-based emissions factors. These emission factors are sourced from the EPA’s GHG Hub and the Carbon Leadership Forum. The Department of Project Management, Business Affairs and Office of Sustainability collaborate to ensure consistent reporting and prevent double counting.
Future Improvements: Transitioning away from spend- based analysis for smaller projects and working with contractors and suppliers to collect real emissions data is an important step towards more accurate emissions reporting.
Leases
Definition: Leased assets include scope 1 & 2 emissions from buildings and facilities that Stanford owns but leases out to third parties and does not directly operate. This includes leases with Stanford Health Care (SHC), Lucile Packard Children’s Hospital (LPCH), and tenants in the Stanford Research Park.
Data: Direct utility or emissions data is used when available. Otherwise, square footage and the building usage type is used to estimate utility-based emissions for these buildings.
Calculating Emissions: A hybrid approach utilizes direct utility data when available and emissions are calculated using emissions factors that are specific to the utility data. When only square footage and building type data are available, Stanford estimates emissions by applying EIA-derived utility usage benchmarks and regional emissions factors.
Future Improvements: Securing direct utility or emissions data for all leased assets and moving away from square- footage based estimates is an important step towards more accurate emissions reporting.
Business Travel
Definition: Stanford defines business travel emissions as all university-sponsored travel undertaken by employees, students, and visitors, including air travel, ground transportation, and lodging. Food and beverage procured during travel are excluded from this category.
Data: Travel data from Stanford’s financial management systems is pulled by the Responsible Purchasing team in Procurement Services. This data includes flight information capturing origin and destination airports, number of hotel nights, and ground travel transaction data.
Calculating Emissions: All air travel emissions are calculated on a passenger-mile basis, using Stanford-specific air travel emissions factors provided by key airline partners. When these are not applicable, emission factors from the EPA are used based on three EPA-defined flight distance categories (e.g., short, medium, and long-haul). A radiative forcing factor of 2.7 is applied to all air travel emissions calculations to account for additional climatic impacts from aviation. Stanford sources lodging emissions factors for hotel nights by country from UK DEFRA, and uses spend-based emissions factors to calculate emissions from ground transportation transactions.
Future Improvements: Growing relationships with more airline partners will increase availability of airline-specific emissions factors. Contact responsiblepurchasing@stanford.edu for more information or to receive a detailed white paper about this methodology, including a study of the most appropriate radiative forcing factor.
Student Travel
Definition: This category includes student travel to and from main campus during breaks and at the beginning and end of the academic year, as well as university-affiliated academic travel such as study abroad. Leisure travel is excluded; all student travel paid for by the University–including student athlete travel–is included in the Business Travel category.
Data: Data is gathered via an annual student survey to a representative sample of undergraduate and graduate students, and study abroad program records. The annual student survey asks students to provide specific flight paths and airlines for travel during each break period and at the beginning and end of the academic year.
Calculating Emissions: All air travel emissions are calculated on a passenger-mile basis, using airline-specific air travel emissions factors provided by key airline partners. When these are not applicable, emission factors from the EPA are used based on three EPA-defined flight distance categories (e.g., short, medium, and long-haul). A radiative forcing factor of 2.7 is applied to all air travel emissions calculations to account for additional climatic impacts from aviation. Emissions from study abroad travel are based on data from 36 academic programs, including Bing Overseas Study Program, Sophomore College, Haas Center for Public Service, and academic grant and fellowship programs, among others.
Future Improvements: Improvements to survey design and efforts to boost survey yield could improve the accuracy of underlying data. Data collection for study abroad programs may also become more precise. Contact responsiblepurchasing@stanford.edu for more information or to receive a detailed white paper about this methodology, including a study of the most appropriate radiative forcing factor.
Employee and Student Commuting
Definition: This category captures emissions from daily commuting between primary residences and Stanford campuses by employees and students. It includes all modes of transportation, such as personal vehicles, carpools and public transit.
Data: Commuting data including commute distance, vehicle make and model, and commuter mode split is collected via annual Stanford Transportation surveys and parking permit records.
Calculating Emissions: Emission estimates are based on commuting distance data to calculate vehicle miles traveled (VMT) per permit holder. Where available, vehicle make and model information is used to determine fuel efficiency (MPG), allowing estimation of fuel consumption. In cases without detailed data, average distances and fuel efficiencies are used. Commuter mode split data informs the average number of commutes per employee, accounting for hybrid and remote work arrangements and the share of commuters traveling by car, bike, bus, train, and other modes. For non-car modes, estimated commute distances are paired with emissions factors specific to each mode.
Future Improvements: Obtaining more detailed data from parking permits—such as comprehensive vehicle make, model, and exact commute distance—which would reduce reliance on average distances and fuel efficiencies.
Fuel & Energy
Definition: This category captures upstream Scope 3 emissions from fuel extraction, production, and transportation.
Data: Data is derived from campus fuel consumption records by unique fuel type.
Calculating Emissions: Stanford applies upstream emissions factors to each fuel type, using resources such as the EPA’s GHG Hub.
Waste
Definition: This category includes emissions from solid waste generated at Stanford Main Campus and Redwood City Campus, including landfill, compost, and recycling streams.
Data: Data is collected from waste processing facility hauling and weight tickets, and is further used and verified through annual waste diversion reports and characterizations studies. Totals by stream are calculated for the main campus and Redwood City.
Calculating Emissions: Stanford uses material categories to match waste with appropriate emissions factors. Emissions are calculated using EPA’s GHG Hub emissions factors by material type.
Future Improvements: While waste generation at Stanford locations beyond the main campus and Stanford Redwood City is significantly less, expanding data collection to include all sites under Stanford’s operational control—such as the Hopkins Marine Station and buildings located outside California—would enhance the comprehensiveness of the waste data. Additionally, ensuring that all waste managed by project contractors during demolition and renovation activities is captured would improve the accuracy of emissions reporting, particularly for construction and demolition waste.
Water
Definition: Water-related Scope 3 emissions include the wastewater treatment from Stanford’s main campus and Redwood City campus.
Data: Water and wastewater data is collected from both the main campus and Redwood City campus. Data is categorized based on whether the wastewater is treated using anaerobic or aerobic methods
Calculating Emissions: Water and wastewater volumes are multiplied by emissions factors from EPA’s GHG Hub. These factors are specific to the type of wastewater treatment, anaerobic or aerobic.
Future Improvement: While water usage at Stanford locations beyond the main campus and Stanford Redwood City is significantly less, expanding data collection to include all sites under Stanford’s operational control—such as the Hopkins Marine Station and buildings located outside California—would enhance the comprehensiveness of the water data.