Scope 3 Emissions Inventory
Scope 3 emissions are indirect emissions from sources that occur as a result of an institution’s operations but from sources not owned or directly controlled by the institution. There are over a dozen categories of Scope 3 emissions, as defined in the Greenhouse Gas Protocol. Stanford has collected and reported data on air travel and commuter emissions for many years, and is now expanding its efforts to conduct a more detailed inventory of its Scope 3 emissions. Data collection is now underway for additional categories such as carbon emission from other modes of travel, purchased goods, and waste transport and landfill. Future categories will include emissions associated with sold products and investments, among others.
Business Travel Emissions
Stanford has collected metrics for business travel emissions from university-sponsored faculty and staff air travel since 2010, shown in the chart below. Emissions included in this category cover all employee air travel funded by Stanford, based on procurement data showing the departure and arrival cities for each trip. These overall emissions have increased slightly over time as the Stanford employee base has grown, but per capita air travel emissions have decreased.
In 2019, the inventory incorporated additional segments of business travel based on new data sets, including estimates for emissions from student air travel. The student air travel data was generated from an inaugural student travel survey coupled with study abroad data. Additionally, emissions from non-air travel by faculty, staff, and students, such as trips conducted by car and trips to and from the airport were incorporated. With this additional data, the university can better understand its full carbon footprint from business travel and the relative breakdown, as shown in the chart below.
Stanford has tracked driving commuter emissions since 2002 based on robust data collected by Stanford Transportation. At Stanford, about 50% of employees use alternative transportation options to get to work. For any mode of transit that involves vehicle emissions, Stanford captures the mode of transit (drive alone, carpool, and vanpool) to apply accurate emissions calculations to the type of commute. For further insight into the emissions data, commuter affiliation is tracked by category, such as graduate students, undergraduate students, and university employees. Overall, commuter emissions have decreased since 2010, as shown in the chart below, due to Stanford’s robust Transportation Demand Management program, which oversees a number of programs to encourage commuters to avoid driving alone to campus.
Stanford began tracking scope 3 emissions from waste generated in university operations for the first time in 2019. Because of Stanford's high diversion rate and the fact that the university sends its waste to landfills that utilize methane capture technology, waste emissions for 2019 were shown to be negative. With estimates of -81 MTCO2e for landfill waste, -865 MTCO2e for compost, -27,296 MTCO2e for recycling, and 184 MTCO2e for wastewater, Stanford's overall emissions from waste in 2019 equate to approximately -28,059 MTCO2e. Additionally, it is estimated that roughly 349 MTCO2e are generated from the transport of Stanford's solid waste, which is included in the total above.
Emissions from Fuel & Energy Related Activities
Stanford began tracking scope 3 emissions from fuel & energy related activities for the first time in 2019. This category captures indirect emissions from transmission and distribution of energy used by the university; the consumption of that energy is captured in Stanford's scope 1 and 2 emissions, which have reduced 68% since 2015. For 2019, it is estimated that the university's scope 3 emissions in this category result in 23,815 MTCO2e of indirect emissions.