Since Duke announced its carbon neutrality achievement in October, the University has maintained that the milestone is just the beginning of its work to become more climate-conscious.
However, 2024 might be the last year Duke is actually carbon neutral for some time.
The University’s carbon neutral status comes with an annual expiration date. To maintain it, Duke must provide an update on its greenhouse gas (GHG) emissions for each new year and cash in carbon credits to cancel them out. These carbon credits and offsets come from external carbon removal or reduction projects, which institutions can buy credits from to “offset” their own emissions.
But once credits are retired, they cannot be used again. That means that all 232,472 credits Duke used last year — which cost $4 million and constituted two-thirds of the University’s 2024 emissions — are gone from its stockpile for good.
Staff had originally estimated that the University would be able to reduce its emissions by roughly 75% by 2024. But delays in projects like new renewable energy facilities forced the University’s hand, pushing it to make additional expenditures to meet the deadline set in 2007.
Now, Duke is looking toward its next climate goal, which aims to invest in sustainability strategies that will be more effective in the long run.
Although conversations are still happening to determine what exactly that will be, staff in the Office of Climate and Sustainability have suggested that a central component will be a shift away from carbon neutrality. Now, they’re aiming for near-total elimination of GHG emissions on campus — and an expansion of which emissions they’re counting.
Framing Duke’s sustainability approach
Reduce, renew, offset
Since the University began tracking its emissions, OCS staff have operated under what they call a “reduce-renew-offset” framework.
The first step entails minimizing the emissions released by the University’s everyday activities — actions like improving the energy efficiency of campus facilities or electrifying Duke’s bus fleet. The second step, “renew,” involves switching to renewable energy to power necessary operations. After all, Duke can’t just stop using electricity on campus or transporting its students, faculty and staff altogether.
“The last thing that you do is offset,” explained Sustainability Director Lindsay Batchelor, stressing that purchasing carbon credits is not “tacked on to [Duke’s] strategy” but rather is “built in as the last piece” to cover emissions that the University has little control over.
Planning the next goal
Going forward, Duke aims to shrink the amount of offsets it must purchase by prioritizing further reductions of campus GHG emissions instead, with the ultimate goal of getting them as close to zero as possible.
“The [Intergovernmental Panel on Climate Change] — the leading scientists in the world — have said that we need to be at zero in 2050,” Batchelor said. “So that doesn’t mean carbon neutral. It means zero.”
Faculty and students in the Climate Commitment Advisory Council’s operations subcommittee are now in the process of developing the University’s next “climate action plan,” which, according to Batchelor, will center around a “science-based target.” The subcommittee’s original strategy outlined in 2009 culminated in the 2024 carbon neutrality achievement.
Matthew Arsenault, assistant director of carbon and sustainability operations, explained that Duke plans to implement a series of interim reduction goals that will act as “milestones where [the University will] be able to check our progress on the route to 2050.”
Batchelor also pointed out that the technology landscape changes at such a rapid pace that identifying a sure-fire long-term emission reduction strategy can be difficult, which is why such intermediate goals can be helpful.
“Do we know the technologies that we’re going to be able to employ to help get us to 2030, six years from now? Yes. Do we know them for 2040? … Things start to get fuzzier,” she said. “… In five years, when we know a little bit more about what the next five years are, then we make revisions and changes and updates to that plan.”
But while Duke continues to finalize the first draft of its climate plan for the next 25 years, some elements have already been made clear.
What to expect from the new 2050 goal
A larger emission boundary
Arguably the most significant update to Duke’s climate strategy going forward is including the Duke University Health System in its emissions tracking scheme.
As part of Duke’s carbon accounting process — the way staff track carbon emissions produced by the University’s operations — leadership must identify a “boundary” around the emissions that are actually measured, with some necessary exclusions.
Through 2024, the University’s campus in Durham, the Marine Lab in Beaufort and the Schools of Medicine and Nursing were all included within Duke’s boundary. However, emissions from the larger DUHS, international campuses like Duke Kunshan University and the Duke-NUS Medical School, the University’s many leased assets and those associated with its endowment were not tracked.
Now, the health system is beginning to add to Duke’s GHG inventory, completing its first full count of carbon emissions last year.
“Completing our first carbon emissions inventory was a significant milestone for DUHS, showcasing our commitment to understanding and mitigating our environmental impact,” wrote DUHS Project Executive Julie Somarriba, Fuqua ‘24, in a Dec. 13 statement to The Chronicle.
DUHS staff tracked the health system’s emissions from fiscal years 2010 and 2023, reporting a 29% reduction in GHG emissions.
A number of sustainability initiatives are responsible for that decrease. The Duke University Medical Center reduced its potable water usage by 30% since 2007, and by February, 50% of its power will come from solar energy. Additionally, the larger DUHS has reduced 375,000 square feet of office space and allocated over $100 million to “renewal projects with increased energy efficiency.”
These examples represent only a few of the health system’s recent achievements, and DUHS is continuing to “evaluate the best projects to pursue,” according to Somarriba. She pointed to “optimizing energy efficiency and reducing reliance on fossil fuels” as remaining areas of interest and stressed that collaborations with Sustainable Duke and the Office of Climate and Sustainability have been an “invaluable” part of that process.
Though specific details about the health system’s ultimate role in Duke’s 2050 climate goal have yet to be released, the “DUHS is actively engaging in discussions to ensure alignment with the broader vision for sustainability,” and its inclusion in Duke’s overall emissions boundary represents a significant step forward.
Still, the DUHS has its own boundary, which Somarriba said was established “using guidance from The Greenhouse Gas Protocol.” Its first emissions inventory included the three Duke hospitals — Duke University Hospital, Duke Regional Hospital and Duke Raleigh Hospital — as well as ambulatory clinics and the Duke Laundry facility. Excluded were facilities where the DUHS has “0% operational control [or] minimal financial control, and leased spaces other than Duke Laundry.”
Even despite these omissions, Batchelor maintained that the inclusion of the DUHS represents “a big addition to [Duke’s] footprint” and “the biggest piece” of the University’s next climate plan.
More emission reductions
While Duke grows the boundary of which emissions are counted, the bulk of its next phase of sustainability work will be focused on further reducing the amount of emissions actually released. The University has already made strides in this space, and it’s looking to continue several projects that are currently underway.
Annual GHG emissions from all sources have decreased by 31% since 2007 levels, despite Duke’s physical footprint expanding by 27% and its campus population growing by 24%. Energy-related emissions alone have decreased by 42% since 2007.
Upgrades to heating and cooling systems are responsible for a large proportion of these reductions.
Duke has two thermal energy plants on campus that provide heat to its facilities through an underground network of steam pipes. As of 2019, steam-powered heating accounted for 49% of campus energy use, while the remaining 51% was made up by electricity use.
In 2011, the steam plant on West Campus was converted from coal power to natural gas, which Duke buys from Dominion Energy North Carolina. Natural gas is a type of fossil fuel, which means it still emits GHGs when burned — though significantly fewer than the amount produced by burning coal.
The University is currently working to lessen the environmental impact of its steam power network. According to Arsenault, Duke is investing in steam-to-hot-water conversions across campus.
“It takes less energy to heat water than it does to boil it into steam,” he said. “So that’s like a decades-long, tens — if not hundreds — of thousands of dollars investment that Duke is making that’s going to continue to reduce energy emissions on campus.”
Duke is also continuing the push to make its buildings more energy efficient.
Duke Facilities Management completed two phases of energy efficiency upgrades already, which entailed installing LED lighting in 15 buildings and bringing 14 major campus facilities up to Leadership in Energy and Environmental Design (LEED) standards. Lifetime cost savings from these projects alone — which covered 1.5 million and 1.7 million square feet, respectively — totaled over $1 million.
As of 2021, 45 buildings on campus were LEED-certified, and six buildings were registered for certification, covering nearly 5.2 million gross square feet of the University’s total 20 million footprint. The University made a commitment in 2004 for all new construction and major renovation projects to achieve LEED Silver certification, and it went a step further in 2018 in developing the High Performance Building Framework, which “takes a holistic view of green building at Duke” to guide future efforts.
Energy-efficiency improvements brought Duke a significant portion of the way to its overall 31% reduction in campus GHG emissions during phase one of its climate work. Though, to improve on that progress during phase two, sustainability staff will likely need to get creative.
Renewable energy investment
As part of its ongoing upgrades to campus facilities, Duke has installed roughly one megawatt (MW) worth of solar photovoltaics and hot water — renewable power sources — across campus over the years, including at the Bryan Center and Grainger Hall.
But another project soon to be completed will bump up the University’s renewable power generation to the tune of 101 MW.
In 2020, Duke purchased solar capacity from Asheville-based Pine Gates Renewables, which is developing three off-campus solar farms to produce the power. The facilities were initially expected to come online in 2022, but lingering supply-chain disruptions from the COVID-19 pandemic have delayed their completion to spring 2025. Once finished, Duke anticipates an annual output of around 240,000 megawatt-hours of power.
The University likely will not receive the actual electricity produced by the solar project, since nearly all power generated in North Carolina — a regulated utility state — is required to go through Duke Energy, which shares a name with the University but is owned and operated separately. In fact, the 2020 solar acquisition was only made possible through Duke Energy’s Green Source Advantage Program, which was spurred by a 2017 state law requiring the utility to allow large consumers the option to receive energy from renewable sources. According to Arsenault, the acquisition “maxed out” the University’s legal renewable allotment through the program.
But although the physical electrons from the electricity generated by the solar project may not make their way onto Duke’s campus, the University will still get credit for helping to get them on the grid — which will be reflected in its emissions reporting for 2025 and beyond.
Remaining obstacles
The biggest challenge Duke faces as it plans for a more ambitious sustainability target is reducing its indirect emissions.
GHG emissions are divided into three “scopes,” or categories. Scope 1 emissions refer to those that are directly produced by an institution’s operations, which for Duke includes fuel use for steam and hot water generation, as well as campus vehicles. Scope 2 emissions are produced by the electricity that an institution purchases from the grid. Scope 3 covers nearly everything else — indirect emissions that result from University-sponsored activities.
In 2024, 30.36% of Duke’s emissions were classified as scope 1, 34.24% as scope 2 and 35.40% as scope 3. Most of the University’s reductions from 2007 levels came from scope 2, with scope 1 emissions not far behind. Scope 3 emissions increased by 16.26% from 2007 to 2024.
“The fact of the matter is, scope 3 starts to get you into a place where you don’t have as much control,” Batchelor said.
Duke’s official GHG emissions reporting breaks down scope 3 emissions for recent years into subcategories that range from University-financed air travel to emissions lost through the transmission of electricity.
According to Batchelor, while Duke creates programs that incentivize community members to become more sustainability-minded — such as alternative transportation options and sustainable dining initiatives — it is up to the individual to change their behavior, making it difficult to systematically reduce emissions in many of these subcategories.
Nevertheless, Duke’s sustainability staff are still working on “framing out” goals and targets for scope 3 emissions, first prioritizing waste and transportation, but eventually moving on to include everything from food and water to landscaping and purchased assets. Bachelor noted that while “some of those things don’t have a huge greenhouse gas impact, they still have a really big sustainability impact.”
Though, attaining sustainability goals for scopes 1 and 2 also comes with its own set of challenges.
The inclusion of the health system in Duke’s emissions tracking scheme means scope 1 emissions are likely to see an uptick in the coming years, compelling staff to find new ways to lower the institution’s overall carbon footprint.
Scope 2 emissions are trickier, given that the University has little to no control over where Duke Energy sources its electricity. That said, Duke Energy is bound by a bipartisan 2021 state law to reduce its GHG emissions by 70% by 2030 compared to 2005 levels. By 2050, the utility must reach full carbon neutrality.
The North Carolina Utilities Commission, however, approved an updated Carbon Plan in November that pushes back the 2030 deadline, maintaining that a delay to at least “beyond 2032 is necessary to maintain the adequacy and reliability of the existing grid.”
Though, the new plan also included provisions to invest in clean energy development — such as through nuclear power plants and offshore wind — that would likely be viewed as a welcome step forward by the sustainability staff at Duke.
With these goals in mind, the University now looks forward to its second-stage climate plan with the intention of getting Duke’s carbon footprint down to zero for good.
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| News Editor
Zoe Kolenovsky is a Trinity junior and news editor of The Chronicle’s 120th volume.
