Yale’s Greenhouse Gas Reduction Strategy — 2019 Update

Background: Establishing our Boundaries

When Yale established the 2005 greenhouse gas emissions baseline, it included energy consumed by all buildings connected to the University’s two on-campus co-generation power plants and purchased electricity[1]. 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[2]. As a separate effort, Yale focuses on emission reductions at West Campus, which was purchased in 2007[3].

Strategy to date

Since 2005, Yale has reduced annual GHG emissions by 20%, despite a 30% increase in campus population and a 21% increase in campus square footage. The cumulative reductions are the result of consistent investments in our central utility systems, our buildings, and in the energy we buy.

Reductions depend on available technology, project economics, and programmatic requirements. Due to these variables, our emissions reduction path has been a combination of annual increases and decreases leading to a net reduction.

What drives these small year-to-year variations?

Seasonal conditions

  • Increasingly warm summer weather requires extra chilled water generation to cool and dehumidify campus buildings. Yale experienced an extended period of heat and humidity through August and September this past year. 
  • In addition, cold weather impacts natural gas supply across the region. To accommodate these regional demands, Yale power plants switch from natural gas to heating oil, a more carbon intensive fuel.

New construction

  • As new buildings open and fill with occupants, they are commissioned to ensure optimal energy performance. This process can take up to two years.
  • During 2019, Yale completed construction and initiated post-occupancy commissioning on several projects of all scales.  Early commissioning also began at Yale Science Building with significant energy impacts.

Yale purchased the Bayer Pharmaceutical campus in 2007 to expand the University’s science and medical research. The 2005 figures represent emissions from Bayer while it was operating at full capacity. Yale has not yet reached full occupancy of the campus.

In 2015, we successfully installed a 90,000 square foot photovoltaic solar array at West Campus. The facility provides 1 megawatt of installed capacity.


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 two 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. 

Inventories for Yale’s Scope 3 emissions associated with employee commuting, business travel, waste generated in operations, purchased goods and services, capital goods, and downstream assets are analyzed on an annual basis but are not currently included in Yale’s emissions reduction target. Efforts to incorporate student travel are underway.

The Climate Registry

In 2014, President Salovey announced that Yale would join The Climate Registry (TCR), a non-profit organization that works with businesses, universities, and other entities on measuring, verifying and reporting on their GHG emissions. The University has since submitted GHG emissions inventories annually since 2014, all of which have been verified by a third party and are available on The Climate Registry website. By pursuing this effort, Yale is showing its commitment to a consistent and transparent standard in GHG emissions accounting.

The numbers reported to the Climate Registry get updated as our access to data increases—as a result, the figures for 2014 and 2015 differ slightly from what appeared in Yale’s 2016 Greenhouse Gas Emissions Progress Report. For more information, visit The Climate Registry.

The numbers at-a-glance

The numbers reported to The Climate Registry differ from the numbers reported in Yale’s annual Greenhouse Gas Emissions Reduction Progress Report in two ways:
  • TCR requires calendar year data, while Yale reports on a fiscal year (June 1-July 30) basis
  • TCR uses an operational boundary[4], whereas Yale reports on energy consumed by all buildings connected to the University’s two on-campus co-generation power plants and purchased electricity.
Despite these differences, Yale’s participation in The Climate Registry has confirmed the accuracy of the University’s methodology to date.
All numbers are listed in metric tons of carbon dioxide equivalent.
Yale Emissions Report
The Climate Registry
2014 227,522 293,588
2015 231,973 283,772
2016 200,961 273,732
2017 200,456 261,362
2018 203,558 278,161
The University will continue to report on its GHG emissions both ways until the conclusion of Yale’s 2005 goal in 2020, at which point we will report exclusively through The Climate Registry. Beginning with the 2017 Climate Registry inventory, we began to analyze a more robust set of Scope 3 categories.

[1] Yale owns and operates two co-generation power plants: Central Power Plant and Sterling Power Plant.
[2] 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.
[3] 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.
[4] The operational boundary includes all owned and leased facilities where Yale holds operational control, and all vehicles that Yale operates.