Overall Rating Gold
Overall Score 66.30
Liaison Stephen Ellis
Submission Date May 31, 2024

STARS v2.2

Boston University
OP-1: Emissions Inventory and Disclosure

Status Score Responsible Party
Complete 1.69 / 3.00 Stephen Ellis
Director, Data Analytics
BU Sustainability
"---" indicates that no data was submitted for this field

Has the institution conducted a GHG emissions inventory within the previous three years that includes all Scope 1 and 2 emissions? :

A copy of the most recent GHG emissions inventory:
A brief description of the methodology and/or tool used to complete the GHG emissions inventory:

Boston University (BU) used the University of New Hampshire's Sustainability Indicator Management and Analysis Platform (SIMAP) to calculate greenhouse gas emissions. Before BU's FY2018 STARS submission, we used an institutional boundary that only included the Charles River and Medical Campuses. Starting in our FY2018 STARS submission, we have expanded our institutional boundary and associated metrics to off-campus facilities within New England. In addition, since June 1, 2018, Wheelock College merged with BU, becoming the Fenway Campus; this campus is now included in our institutional boundary from the last month of FY2018. We have uploaded FY 2006 through 2023 data into SIMAP. BU uses an FY2006 baseline year for all sustainability-metric data. 

We account for:

  • Scope 1 emissions of :

    • stationary combustion of fossil fuels on campus,

    • transportation-related fossil fuel consumption,

    • emissions from refrigerants & chemicals, and

    • fertilizers,

  • Scope 2 emissions of:

    • electricity and

    • steam

  • BU has elected to include Scope 3 emissions associated with our: 

    • waste stream (specifically, incinerated waste).

      • BU Sustainability undertook a waste emissions project which produced a Waste Calculator to derive BU’s greenhouse gas emissions associated with waste. Through the Calculator, raw waste data is disaggregated by material type and stream category, mapped to its corresponding WARM (US EPA’s Waste Reduction Model) material type, and associated with the corresponding emissions factors for each material. This is then summarized in a pivot table that sums the yearly combustion generation—among other factors—by material type.

Has the GHG emissions inventory been validated internally by personnel who are independent of the GHG accounting and reporting process and/or verified by an independent, external third party?:

A brief description of the GHG inventory verification process:

Documentation to support the GHG inventory verification process:

Gross Scope 1 GHG emissions, performance year:
Weight in MTCO2e
Stationary combustion 46,500 Metric tons of CO2 equivalent
Other sources (mobile combustion, process emissions, fugitive emissions) 1,900 Metric tons of CO2 equivalent

Total gross Scope 1 GHG emissions, performance year:
48,400 Metric tons of CO2 equivalent

Gross Scope 2 GHG emissions, performance year (market-based):
Weight in MTCO2e
Imported electricity 0 Metric tons of CO2 equivalent
Imported thermal energy 9,200 Metric tons of CO2 equivalent

Total gross Scope 2 GHG emissions, performance year:
9,200 Metric tons of CO2 equivalent

Gross GHG emissions from biogenic sources, performance year:
0 Metric tons of CO2 equivalent

Does the GHG emissions inventory include Scope 3 emissions from the following sources?:
Yes or No Weight in MTCO2e
Business travel No ---
Commuting No ---
Purchased goods and services No ---
Capital goods No ---
Fuel- and energy-related activities not included in Scope 1 or Scope 2 No ---
Waste generated in operations Yes 1,500 Metric tons of CO2 equivalent
Other sources No ---

Total Scope 3 GHG emissions, performance year:
1,500 Metric tons of CO2 equivalent

A brief description of how the institution accounted for its Scope 3 emissions:

The quantification of emissions from Boston University’s waste streams follows a similar method to that utilized for the Carbon Free Boston study as described in its Waste Sector Technical Report and in a related peer-reviewed publication in Waste Management. In this approach material- and waste-treatment-specific emissions factors are applied to BU’s waste generation data. Emissions factors were extracted from the U.S. Environmental Protection Agency’s Waste Reduction Model’s (WARM) version 15 documentation, specifically the Waste Management Practices documentation. These emissions factors have been updated from those used in the Carbon Free Boston study, which used WARM version 14 emissions factors. Emissions factors for avoided emissions from electricity generation were calculated using WARM’s material-specific electricity generation factors (e.g., MWh per ton waste) and emissions factors for regional electricity production (e.g., tonne CO2 per MWh electricity) assuming that electricity generated from combustion displaced marginal, typically natural gas, generators.

Has the institution completed an inventory within the previous three years to quantify its air pollutant emissions?:

Annual weight of emissions for::
Weight of Emissions
Nitrogen oxides (NOx) 54.12 Tons
Sulfur oxides (SOx) ---
Carbon monoxide (CO) 45.02 Tons
Particulate matter (PM) 2.53 Tons
Ozone (O3) ---
Lead (Pb) ---
Hazardous air pollutants (HAPs) ---
Ozone-depleting compounds (ODCs) ---
Other standard categories of air emissions identified in permits and/or regulations 10.91 Tons

Do the air pollutant emissions figures provided include the following sources?:
Yes or No
Major stationary sources Yes
Area sources Yes
Mobile sources ---
Commuting ---
Off-site electricity production ---

A brief description of the methodology(ies) the institution used to complete its air emissions inventory:

BU inventories all emission-producing equipment in its buildings and calculates potential emissions using emissions guarantees and EPA-approved emission factors for criteria and GHG emissions. Actual emissions are calculated using fuel use or run times of each emission-producing equipment.  As of CY2021, Boston University has outsourced its air pollution inventory to Epilson Associates. Please see the most recent report below:

CY2022 Report:

Pollutant    2022
PM10         1.28
PM2.5        1.25
SO2            5.01 (added to "Other")
VOC           5.90 (added to "Other")
CO             45.02
NOx           54.15

Gross Scope 2 GHG emissions from purchased electricity (location-based):

Gross Scope 2 GHG emissions from imported thermal energy (location-based) :

Website URL where information about the institution’s emissions inventories is available:

Additional documentation to support the submission:

Data source(s) and notes about the submission:

As part of our Climate Action Plan, BU matches 100% of our scope 2 electricity needs by retiring Renewable Energy Certificates (RECs) from the BU Wind Farm. This project came online in December 2020 in the middle of FY2021 and reduced our carbon emissions by 58.3%. It has continued since and matched 100% electricity for FY2023. Hence the drop in electricity emissions from previous years is from BU Wind Farm matching electricity by wind power.

This represents FY2023 BU Metrics.

The information presented here is self-reported. While AASHE staff review portions of all STARS reports and institutions are welcome to seek additional forms of review, the data in STARS reports are not verified by AASHE. If you believe any of this information is erroneous or inconsistent with credit criteria, please review the process for inquiring about the information reported by an institution or simply email your inquiry to stars@aashe.org.