Overall Rating Silver
Overall Score 64.62
Liaison Sarah Fortner
Submission Date March 3, 2022

STARS v2.2

Carleton College
OP-2: Greenhouse Gas Emissions

Status Score Responsible Party
Complete 5.90 / 8.00 Alexandra Miller
Sustainability Program Coordinator
Energy and Sustainability
"---" indicates that no data was submitted for this field

Scope 1 and Scope 2 GHG emissions

Gross GHG emissions

Gross Scope 1 and Scope 2 greenhouse gas (GHG) emissions:
Performance year Baseline year
Gross Scope 1 GHG emissions from stationary combustion 3,783 Metric tons of CO2 equivalent 8,482 Metric tons of CO2 equivalent
Gross Scope 1 GHG emissions from other sources 275 Metric tons of CO2 equivalent 155 Metric tons of CO2 equivalent
Gross Scope 2 GHG emissions from imported electricity 3,000 Metric tons of CO2 equivalent 11,205 Metric tons of CO2 equivalent
Gross Scope 2 GHG emissions from imported thermal energy 0 Metric tons of CO2 equivalent 0 Metric tons of CO2 equivalent
Total 7,058 Metric tons of CO2 equivalent 19,842 Metric tons of CO2 equivalent

Carbon sinks

Figures needed to determine net carbon sinks:
Performance year Baseline year
Third-party verified carbon offsets purchased 190 Metric tons of CO2 equivalent 0 Metric tons of CO2 equivalent
Institution-catalyzed carbon offsets generated 0 Metric tons of CO2 equivalent 0 Metric tons of CO2 equivalent
Carbon storage from on-site composting 0 Metric tons of CO2 equivalent 0 Metric tons of CO2 equivalent
Carbon storage from non-additional sequestration 653 Metric tons of CO2 equivalent ---
Carbon sold or transferred 0 Metric tons of CO2 equivalent 0 Metric tons of CO2 equivalent
Net carbon sinks 190 Metric tons of CO2 equivalent 0 Metric tons of CO2 equivalent

If total performance year carbon sinks are greater than zero, provide:

A brief description of the carbon sinks, including vendor, project source, verification program and contract timeframes (as applicable):
The carbon sequestration from is from our Arboretum, which was calculated by an Ecosystems Ecology class on campus and this number has stayed constant. Renewable Energy Credits, RECs, are purchased through the Renewable Connect Program offered by our utility provider, Xcel Energy. We purchased RECs in an amount that is approximately equivalent to the generation from our first wind turbine which serves the public grid.

RECs are included directly into our Scope 2 emissions, so that figure shows net emissions, not gross.

Significant reductions in our scope 2 emissions this year due to the fact that we are purchasing RECs back for our first wind turbine (erect in 2004) that supplies the public grid. FY21 was the first year we were able to count the RECs toward our Scope 2 emissions.

Adjusted net GHG emissions

Adjusted net Scope 1 and Scope 2 GHG emissions:
Performance year Baseline year
Adjusted net GHG emissions 6,868 Metric tons of CO2 equivalent 19,842 Metric tons of CO2 equivalent

Performance and baseline periods

Start and end dates of the performance year and baseline year (or three-year periods):
Performance year Baseline year
Start date July 1, 2020 July 1, 2007
End date June 30, 2021 June 30, 2008

A brief description of when and why the GHG emissions baseline was adopted:
The GHG emissions baseline was adopted because 2008 is the first year in which we have comprehensive GHG data validated by Sightlines.

Part 1. Reduction in GHG emissions per person

Weighted campus users

Figures needed to determine “Weighted Campus Users”:
Performance year Baseline year
Number of students resident on-site 1,449 2,000
Number of employees resident on-site 23 40
Number of other individuals resident on-site 0 0
Total full-time equivalent student enrollment 1,918 1,975
Full-time equivalent of employees 817 664
Full-time equivalent of students enrolled exclusively in distance education 274 0
Weighted Campus Users 2,213.75 2,489.25

Metrics used in scoring for Part 1

Adjusted net Scope 1 and 2 GHG emissions per weighted campus user:
Performance year Baseline year
Adjusted net Scope 1 and 2 GHG emissions per weighted campus user 3.10 Metric tons of CO2 equivalent 7.97 Metric tons of CO2 equivalent

Percentage reduction in adjusted net Scope 1 and Scope 2 GHG emissions per weighted campus user from baseline:
61.08

Part 2. GHG emissions per unit of floor area

Performance year floor area

Gross floor area of building space, performance year:
2,069,322 Gross square feet

Floor area of energy intensive building space, performance year:
Floor area
Laboratory space 196,228 Square feet
Healthcare space 550 Square feet
Other energy intensive space 79,965 Square feet

EUI-adjusted floor area, performance year:
2,542,843 Gross square feet

Metric used in scoring for Part 2

Adjusted net Scope 1 and 2 GHG emissions per unit of EUI-adjusted floor area, performance year:
0.00 MtCO2e per square foot

A brief description of the institution’s GHG emissions reduction initiatives:
In summer 2017 Carleton began a five-year transformation of its district heating system from steam to hot water tied to a geothermal heat pump system. This will reduce both plant operating costs and Scope 1 and 2 emissions.

In fall 2019, Carleton will open its new science facility which adds net 50,000 square feet to the science complex without add to the energy footprint. Carleton engaged in the Energy Design Assist, EDA, program offered through our utility provider, Xcel Energy, to develop an energy model based on the design and select energy efficiency measures that will lower the energy intensity compared to a typical science building. The building is currently tracking toward LEED Platinum.

Renewable Energy Credits, RECs, are purchased through the Renewable Connect Program offered by our utility provider, Xcel Energy. We purchased RECs in an amount that is approximately equivalent to the generation from our first wind turbine which serves the public grid.

Ongoing efforts to manage energy data and track energy use have led to numerous energy conservation projects across campus. An "Energy Management Team" consisting of sustainability staff, maintenance staff, the campus energy manager, and students meets weekly to review current project opportunities and log progress.

In fall 2011, Carleton installed its a 1.68 MW wind turbine, which currently produces about 30% of campus electricity. Solar arrays were also installed on Cassat and James residence halls. In terms of future planning, Carleton recently reviewed and modified its architectural master plan, which greatly reduced projections for increased floor space, by renovating or replacing existing structures.

Website URL where information about the institution's GHG emissions is available:
Additional documentation to support the submission:
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Data source(s) and notes about the submission:
Baseline year for Carleton College's GHG inventory is fiscal year 2008, performance year is fiscal year 2019. This encompasses the period of years when Carleton worked with Sightlines, so data and comparisons should be consistent.

Our Scope 3 measurements have increased in accuracy since 2008 (air travel and waste data tracking has improved) resulting in a general increase to these values. "other Scope 3" includes T&D losses, wastewater treatment, and study-abroad air travel.

Our Scope 1 & 2 emissions have improved in purchased electricity, despite adding two residence halls and a large academic building since 2008. This is primarily due to the addition of a 1.68 MW wind turbine in fall 2011.

Significant reductions in our scope 2 emissions this year due to the fact that we are purchasing RECs back for our first wind turbine (erect in 2004) that supplies the public grid. FY21 was the first year we were able to count the RECs toward our Scope 2 emissions.

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.