Harvard’s annual sustainability report, released October 4, details the University’s efforts to prepare for two fast-approaching goals: to be fossil-fuel neutral by 2026, and fossil-fuel free by 2050. Already, less beef is being consumed in Harvard dining halls (lowering the emissions and ecological impacts associated with raising cattle); water use is down; and one-third of the University bus fleet has transitioned to electricity—on track to be all-electric by 2035. But the real key to reaching both stated sustainability goals lies in the operation of 27 million square feet of facilities, distributed across 650 buildings, which account for 98 percent of the University’s carbon emissions (scope one and two), says Heather Henriksen, managing director of Harvard’s Office of Sustainability. (Scope one emissions come from sources the University owns or controls directly. Scope two emissions are released by providers from whom the University purchases electricity and other forms of energy.) Emissions-reduction efforts coordinated through her office are therefore focused on removing fossil fuels within every major renovated, upgraded, and newly commissioned building. And a parallel effort to reduce the embodied carbon associated with building materials and construction activities—for new construction, typically equivalent to about 20 years of a building’s operating emissions—is now underway.
The University’s carbon dioxide equivalents emissions, tracked annually, reached a pandemic nadir in 2020, when the campus shut down. Since then, as students and staff have gradually returned to campus, emissions have risen in turn. But they remain similar to the pre-pandemic level of 196,000 metric tons of carbon dioxide equivalents measured in 2019, despite campus growth. 2023 emissions totaled 198,000 metric tons of CO2 equivalents, about 30 percent lower than they were in 2006, when the University set a goal of reducing its scope one and two net carbon emissions by 30 percent. Since 2006, the physical plant has grown 16 percent, meaning emissions are down about 40 percent on a space-adjusted basis.
But meeting the 2026 goal of fossil-fuel neutrality, now just 13 months away, is likely to require purchase of a combination of renewable energy certificates and carbon credits, or “offsets,” among the strategies to balance the emissions attributable to the use of fossil-fuels in the electricity purchased from local utilities and generated in Harvard’s own energy plants. Renewable energy certificates (RECs) involve purchases of power directly from renewable-electricity generators, an approach that Harvard has used in prior years. But the University’s Fossil Fuel-Neutral by 2026 subcommittee noted in its 2021 recommendations that purchases of RECs offset greenhouse gas emissions but not necessarily atmospheric pollutants that harm human health and the environment, as the University specified in its 2026 goal. Speculatively, future strategies for meeting emissions goals are therefore likely to involve direct investment in new renewable-energy generation projects, to guarantee the comprehensive benefits the University’s goal requires.
Establishing Construction Standards
Recognizing the large role of buildings in overall emissions, the University this fall adopted improved sustainable building standards (first developed in 2009) for new construction projects and gut renovations greater than 20,000 square feet. The standards cover three areas that initially appeared as priorities in the sustainability plan of 2023—health, climate, and equity—representing a holistic approach to human and planetary health by considering the range of impacts from fossil-fuel combustion, not just the release of planet-warming gases. In the category of health, for example, the standards outline best practices for removing harmful chemicals from construction materials supply chains, a practice pioneered during construction of the Science and Engineering Complex in Allston. They also specify strategies for enhancing indoor air quality.
The climate standards specify that no new combustion-based systems or equipment can be installed within buildings, and also address the use of refrigerants for cooling, embodied carbon, and resilience of University structures to future climate impacts such as increased heat and precipitation, or rising sea level.
Finally, projects must meet Harvard’s construction inclusion guidelines—the equity portion of the goals—so that women and minority-owned businesses, for example, will participate in the construction process.
Adoption of these building standards is expected to enhance health and address historic inequities while reducing the carbon intensity of campus buildings—the latter making the 2026 and 2050 emissions goals easier to achieve.
To speed the pace of energy-reducing innovations, President Alan Garber recently increased the funding for “green” projects from $12 million to $37 million. This revolving fund, which has provided capital for implementing energy-saving campus design, operations, maintenance, and occupant behavior modification projects, began in 2002. Since then, according to the project website, it has supported nearly 200 projects that have realized more than $4 million in annual energy savings. With the increase in capital comes an expanded scope for the fund: the financial resources can also be used for electrification projects in support of Harvard’s fossil fuel-free by 2050 goal.
Reducing Embodied Carbon
The University previously used LEED certification to ensure that its building projects meet the highest standards (LEED, or leadership in energy and environmental design, is a series of standards for sustainable structures set by the U.S. Green Building Council, a nonprofit building-industry consortium.) But current and future projects will be measured instead by 10 core imperatives of a more recently devised standard known as the “Living Building Challenge.” Energy and carbon reduction are just one aim of these standards, which include goals for use of responsible materials, water consumption, healthy interior environments, universal access, and so on.
During the renovation of the Goel Quantum Science and Engineering building (60 Oxford Street) as a new hub for quantum science and engineering, for example, the project team was able to achieve nearly a 60 percent reduction in operational emissions (a cut beyond required energy codes and especially challenging in an existing building with an energy intensive optics research lab) and a 23 percent reduction in embodied carbon during the redesign, reports vice president for campus services Sean Caron. Across the river in Allston, the structures of both the Goel Center for Creativity and Performance, which will house the American Repertory Theater, and the University’s David Rubinstein Treehouse Conference Center located at the entrance to the enterprise research campus (now rising rapidly) will incorporate mass timber (engineered wood). Mass timber is lower in embodied carbon than conventional building materials because its production is much less carbon-intensive than typical structural materials such as steel and concrete.
The Treehouse is also expected to be the first building in Massachusetts to use concrete made from cement that incorporates recycled glass rather than fossil-fuel byproducts such as fly ash and slag in its manufacture. The use of ground glass as a “pozzolan” to replace fly ash can reduce the embodied carbon in cement by as much as 95 percent. Largely as a result of using these low-carbon materials, the conference center is projected to achieve at least a 50 percent reduction in embodied carbon compared to a conventional building of similar size and function.
Operational Challenges
Both the conference center and the theater complex will connect to Harvard’s natural-gas-fueled district energy facility in Allston, which supplies chilled and low-temperature hot water for heating and cooling nearby buildings—“best in class from an efficiency standpoint” says Caron, and well suited for eventual conversion to renewable electric energy.
More challenging is reducing the carbon emissions associated with operation of buildings in Cambridge connected to facilities such as the Blackstone power plant, which produces steam—a means of heating that does not lend itself well to the use of renewable sources in an urban environment with limited space, and infrastructure that passes beneath city streets. In an interview, Henriksen noted that the University is being careful not to miss opportunities now that might make a future transition easier. “If we are doing a major renovation on a building that is connected to Blackstone, we’re focused on energy load reduction and energy recovery opportunities, and making sure [that the building] is low-temperature hot water ready…[to] preserve our flexibility and our options for the future. And we are replacing fossil fuel equipment in buildings with modern heat pump technology where possible. These are things that we are doing today to make progress and to prepare for future district energy technology solutions.”
By updating building standards, allocating additional capital to energy-reduction and conversion projects, and pushing the limits of what can be achieved in materials specifications, the University is taking a comprehensive approach to achieving its long-term goal of being fossil-fuel free by 2050—implying a sustained program of capital spending looming large in Harvard’s future finances. Beyond that, the key to the plan—in which electrification of all operations is the centerpiece—will be decarbonization of the utility grid itself, a task even larger than Harvard’s own energy transformation.