Yale’s Greenhouse Gas Reduction Strategy

Establishing our Boundaries


Yale’s current greenhouse gas emissions boundary is operational, which means that we report emissions associated with all buildings over which Yale has operational control. This includes all owned and leased facilities where Yale holds operational control, and all vehicles that Yale operates.


Yale has reported its scope 1 and scope 2 emissions to The Climate Registry (TCR) since 2014. TCR is a non-profit organization that works with businesses, universities, and other entities on measuring, verifying and reporting on their GHG emissions. The University has submitted GHG emissions inventories annually since 2014, all of which have been verified by a third party and are available to members of The Climate Registry. By pursuing this effort, Yale is showing its commitment to a consistent and transparent standard in GHG emissions accounting. For more information, visit The Climate Registry.

Historical inventory emissions that appear on our website may be slightly different than what is reported in The Climate Registry platform due to continual improvements in data quality and availability, methodology updates, and structural changes within Yale’s real estate portfolio.  As a result, there can be minor adjustments to emissions in previous years in an effort to enhance data completeness, consistency, and accuracy.

Yale’s Commitment to Zero Emissions

Yale is committed to achieving zero actual carbon emissions by 2050 with an interim goal to reach net zero emissions by 2035. Reduction efforts are being measured against a baseline of fiscal year 2015 levels. Since 2015, Yale has invested in reducing energy demand and improving energy supply with high performance new construction, portfolios of energy conservation measures within existing buildings, and targeted operations.

In 2023, Yale continued its wide-scale building energy monitoring system at the device level, using Automated Fault Detection and Diagnostics (AFDD). In the past year, this comprehensive process enabled our in-house staff to help identify efficiency and operational issues with building ventilation systems; make repairs in a timely manner; and ultimately save energy and avoid GHG emissions. In 2023, we prevented an additional 6,000 MMBTU of energy from being wasted, and the AFDD process is expanding moving forward to capture additional savings opportunities. 

Gross emissions decreased between 2022 and 2023 by 4%, putting emissions back in line with expected trajectory. A relatively mild winter combined with limited curtailment helped offset observed emissions that resulted from the hotter summer months. Even though we brought online substantial new spaces including Kline Tower and the Economics building, we were able to mitigate the emissions impact through intentional design and operational improvements in other areas around campus.

Moving forward, we are expanding our Automated Fault Detection and Diagnostics (AFDD) monitoring system to now include West Campus. We expect to start seeing increases in efficiency in the second half of fiscal year 2024.

Scope of Emissions

Based on guidance from the Greenhouse Gas Protocol, Yale’s emissions can be divided into three categories called “scopes” depending on the university’s level of control over the source activities.

  • Scope 1: Direct emissions from sources owned or controlled by Yale, emissions from Yale’s fleet of vehicles, and emissions from its three power plants. 
  • Scope 2: Indirect emissions from purchased electricity and purchased co-generation for heating or chilled water. 
  • Scope 3: Indirect emissions from all other sources that occur as a result of Yale operations but occur from sources not owned or controlled by the University, such as employee commuting, air travel, and paper consumption. 

Data for Yale’s Scope 3 emissions associated with employee commuting, business travel, waste generated in operations, purchased goods and services, capital goods, and student travel are being assessed but are not currently included in Yale’s emissions reduction target. Learn more about Yale’s work on Scope 3 emissions.

Yale’s 2005 Greenhouse Gas Emissions Goal

Yale’s original greenhouse gas emissions goal—to reduce emissions by 43% below 2005 levels—also included scopes 1 and 2, but the boundary only included energy consumed by all buildings connected to the University’s two on-campus co-generation power plants and purchased electricity. It did not include energy consumed by buildings not connected to the campus energy grid or the university fleet.

Beginning in 2013, the 2005 baseline was adjusted to include emissions from the university fleet. Though it represents only a small percentage of Yale’s total greenhouse gas emissions, the fleet was added to more accurately reflect the university’s Scope 1 emissions sources[1]. West Campus was not included in the original 2005 goal, but we began to track emissions once we acquired the campus in 2007[2].

Yale achieved its 2005 goal in 2020, despite a 21% increase in campus square footage. Three-fifths of these reductions were the result of consistent investments in our central utility systems, our buildings, and in the energy we buy. The remaining reductions came from the retirement of verified carbon offsets.

[1] Based on guidance from the World Resource Institute and the World Business Council on Sustainable Development, the Greenhouse Gas Protocol defines three scopes of emissions sources. Scope 1 is a direct emission and scopes 2 and 3 are indirect emissions.

[2] West Campus, the former Bayer Pharmaceutical facility, is a 136-acre campus made up of 1.6 million square feet of laboratories, offices, and warehouse space.