Duke announced last week that it fulfilled its pledge to become carbon neutral by 2024, one of only 14 U.S. colleges and universities to reach the milestone.
Over the past 17 years, the University has reduced its greenhouse gas emissions by 31% despite growing its physical footprint by 27% and its campus population by 24%. The achievement was made possible by reductions in energy use and investment in renewable sources, as well as the purchase of $4 million worth of “high-quality” carbon offsets.
“This is a remarkable accomplishment and a critical milestone for the Duke community,” President Vincent Price said. “… This is an achievement we can all be proud of, and one that I hope will only strengthen our momentum as we pursue our bold ambitions through the Duke Climate Commitment.”
Duke originally made the carbon neutrality commitment in 2007, when then-President Richard Brodhead signed the American College and University Presidents’ Climate Commitment alongside 283 other institutional leaders, becoming part of nonprofit Second Nature’s Climate Leadership Network. There are currently 385 active signatories.
According to an Oct. 16 Duke Today announcement, Duke is “by far the largest in terms of student population and greenhouse gas emissions” to have achieved carbon neutrality, as the remaining 13 institutions are “smaller and more specialized.”
However, not all parts of Duke are included in the institution’s carbon tracking metrics.
Tavey Capps, executive director of climate and sustainability, shared in a student town hall last year that while the main University campus, the Schools of Medicine and Nursing and the Duke Marine Lab are included, the Duke University Health System, Duke’s leased assets and international campuses like Duke Kunshan University and the Duke-NUS Medical School are not. Emissions from Duke’s investments are also not considered.
Duke’s Office of Climate and Sustainability is hosting a Climate Commitment Celebration Event Thursday in Page Auditorium to commemorate the second anniversary of the University’s Climate Commitment and the carbon neutrality achievement.
Achieving carbon neutrality
Greenhouse gas emissions are typically divided into three “scopes,” or source categories.
Scope 1 emissions entail those that are directly produced by a facility, which in Duke’s case means all fuel use on campus for activities like generating steam and hot water, as well as transportation. Scope 1 emissions account for 30% of Duke’s campus emissions.
Since 2007, Duke has reduced its campus energy use by 42% despite growing its physical footprint by 3 million square feet. The University has upgraded a third of heating and cooling systems across campus by replacing steam heating systems with hot water-based ones and installing air conditioning in three chiller plants to lower energy demand.
Scope 2 emissions are all those associated with energy purchased from a utility company, accounting for 34% of Duke’s campus emissions. Duke’s utility is Duke Energy, which provides electricity to most of North Carolina. Although the companies share a namesake, they are independent from one another.
Scope 3 emissions, also known as “value chain” emissions, comprise all remaining indirect emissions that are not fully under an organization’s control but occur as a result of its activities. Examples at Duke include fuel consumed by employees commuting to campus, travel paid for by the University and waste generated on campus. Scope 3 emissions made up the largest share of Duke’s emissions this year, accounting for roughly 36%.
The bulk of Duke’s emissions reduction came in the form of Scope 1 and 2 emissions, while Scope 3 emissions were largely offset by redeeming carbon credits. Duke has accumulated a vast number of carbon credits over the past decade, 232,000 of which it redeemed this year to reach the net zero milestone.
Matthew Arsenault, Duke’s assistant director of carbon and sustainability operations explained offsets as “abstract things that represent greenhouse gases that have been removed or avoided from being released into the atmosphere.” For example, emissions are commonly ‘offset’ by investing in practices like planting trees — which take in carbon dioxide as part of the photosynthesis process — to ‘cancel out’ the carbon emitted by a particular facility.
Carbon offsets are assigned a certain number of carbon credits, with each credit representing one metric ton of carbon emissions essentially removed from the atmosphere. Third-party firms handle carbon credit verification, assigning each credit a serial number and tracking their movement.
Duke’s offsets strategy, first outlined in its 2009 Climate Action Plan, leverages the University’s access to local resources in the southeastern U.S. and its international reach to build a wide carbon credit portfolio.
This year, the University cashed in credits from its role in a partnership at a North Carolina hog farm that captures methane emissions and turns them into usable energy, urban tree planting initiatives, and an international company that destroys refrigerants, which are potent greenhouse gases called hydrochlorofluorocarbons that can leak into the atmosphere when stored improperly.
Toddi Steelman, vice president and vice provost for climate and sustainability, acknowledged in a Monday email to The Chronicle that the University may receive criticism for incorporating offsets as part of its carbon neutrality approach.
“That is a fair criticism,” she wrote. “But I hope it doesn’t detract too much from the efforts put forth by so many to genuinely tackle a major operational challenge, which also had the consequence of building empathy for how challenging this work is.”
A “next-generation” climate goal
Conversations are already taking place to determine Duke’s next climate goal.
“Achieving this milestone has been hard fought, humbling work and we are not yet done — in many ways we are just beginning,” Steelman wrote in the Monday email.
University leaders aim to establish new objectives for 2050, which will be developed during the 2024-25 academic year and will take into account “sustainable operations goals and strategies for areas such as waste, transportation, food and water,” according to Sustainability Director Lindsay Batchelor.
A big step for the “next-generation climate action plan” will be incorporating the Health System, including “all of its buildings on campus and around the Triangle area.” The Health System will be responsible for establishing its own targets in line with Duke’s larger goals.
The University also intends to reduce its reliance on carbon offsets over time, and there are a number of projects already in the works to do so.
Duke is in the process of constructing three off-campus solar facilities, which will slash emissions even further. The project was originally scheduled to be completed before the 2024 goal. Now, it’s projected to finish in mid-2025 after experiencing delays due to supply chain disruptions during the COVID-19 pandemic.
First announced in 2020, the facilities are being developed through a partnership with Asheville-based Pine Gate Renewables. The 101-megawatt project is expected to meet roughly half of Duke’s campus electricity needs, generating up to 240,000 megawatt-hours of energy per year.
In the initial announcement, the project was advertised as the largest such initiative in the state under Duke Energy’s Green Source Advantage Choice program, which was established in its original form in 2017 following the passage of House Bill 589 by the N.C. General Assembly. The program aims to provide a path for large energy consumers — like universities — to directly procure renewable energy, with Duke Energy offering energy production and storage options.
Construction is underway for a new hot water system that uses electric pumps instead of natural gas-fired boilers, which is expected to reduce building heating energy use by up to 30%. Multiple buildings across campus are also being upgraded to improve energy efficiency.
In terms of transportation, Duke is in the process of electrifying its C1 bus fleet. According to the Oct. 16 announcement, there are currently nine hybrid and six fully electric buses in operation, and four more fully electric buses are slated to be added in 2025.
Reducing Scope 3 emissions from employee commutes and air travel remains a significant hurdle. The University saw significant improvements during the COVID-19 pandemic, with commuting emissions down 85% and air travel emissions down 98% from 2019 to 2021. But while commuting emissions have stayed somewhat lower, air travel is back to pre-pandemic levels.
Larger than net zero
Climate leaders at Duke have emphasized that while it is an important achievement, carbon neutrality is only one facet of the University’s climate efforts.
"In many ways, this carbon neutrality achievement is just the beginning of a much larger culture shift and transformation," Steelman said. "… We want wholesale change.”
As the primary authority over Duke’s Climate Commitment, which was first announced in September 2022, Steelman hopes to turn Duke into a “climate university.”
She expanded on this goal at a student town hall last Thursday, outlining her vision for Duke to become known for its expertise in climate and sustainability issues and attract students specifically interested in those fields.
“What we really want to do is take the entire mission of Duke University and force it through a prism of climate and sustainability,” Steelman said at a prior town hall last year. “We want to create climate fluency by educating and deploying a generation of climate- and sustainability-fluent changemakers.”
The University has launched a number of programs over the last two years to augment its work in the climate space.
The Office of Climate and Sustainability was officially created last October to coordinate work between several existing departments and organizations, like the Nicholas Institute for Energy, Environment and Sustainability and Sustainable Duke.
The OCS has since established a Climate Commitment Advisory Council composed of students and faculty to advise University leadership on climate-related issues across research, education, operations, community partnerships and external engagement.
Engaging student voices has remained a priority of Climate Commitment leadership.
At a March student town hall — the third of four organized thus far to discuss progress on the Climate Commitment and hear student feedback — Batchelor solicited audience suggestions to guide future work following the University’s carbon neutrality achievement.
The most common proposal then was for Duke to divest its endowment from fossil fuels.
The demand has been a point of contention between students and University administration for over a decade since student group Divest Duke — now Duke Climate Coalition — was established in 2012 and began mobilizing around the issue.
In addition to organizing campus protests, DCC has submitted multiple reports to the Advisory Committee on Investment Responsibility — which advises the president on his recommendations to DUMAC, Inc., the external body that manages investment of the University’s endowment — advocating for divestment from fossil fuels.
Duke has yet to make much movement on the issue, with ACIR releasing a report last spring advocating against divesting the University’s endowment from fossil fuel companies because it did not find “compelling evidence” that doing so “would achieve the desired outcome.”
The OCS organized a nine-part seminar series last year bringing together community stakeholders and expert speakers to discuss the issue. In the final session, participants came to the conclusion that Duke has an obligation to pursue sustainable and climate-conscious investment management strategies in order to be aligned with the University’s mission, though they disagreed on the best approach.
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Zoe Kolenovsky is a Trinity junior and news editor of The Chronicle's 120th volume.