Luke LombardiAs electrification has shifted operational emissions out of buildings and onto the power grid, the embodied carbon of buildings has drawn the attention of the architecture, engineering, and construction industry, ranking as a new priority in reaching the industry’s midcentury climate goals.
“Building practitioners are working to measure and reduce embodied carbon on their projects and engage building owners to commit to reducing the embodied carbon of their portfolios,” according to the Carbon Leadership Forum’s 2025 Embodied Carbon Benchmark Report. “Policymakers at every level of government are starting to consider how to reward, encourage, and regulate reductions in embodied carbon.”
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A building’s operational emissions describe the greenhouse gases released while powering the building throughout its life. Its embodied carbon describes the up-front emissions paid during the manufacture, transport, construction, and demolition of its materials.
Luke Lombardi, M.ASCE, co-chair of ASCE’s Structural Engineers 2050 Commitment Program, sees structural engineers influencing embodied carbon either through designs or specifications.
“In design, we’re thinking about, ‘How can we optimize to select systems that either use less material or use lower-carbon materials?’” Lombardi said. “Once we have a system and designs, (and) we’ve established how much material is going into the building, then we can work with contractors to identify materials that are lower carbon.”
He says that, to avoid the tragedy of the commons inherent in carbon emissions, actors across disciplines – whether in policymaking, private practice, or the public sector – must recognize their individual responsibilities.
“What we’re encouraging is a lot more collaboration to address the problem,” Lombardi said. “It needs to be all of our responsibility. It’s not just the structural engineer’s. Obviously, we don’t have unilateral control over decisions for projects, but it is our responsibility – if we know about it – to educate our clients and to advocate with our peers and architects and other designers.”
SE 2050 works toward bringing the embodied carbon within structural systems to zero by 2050. Firms can sign on to the program and commit to progressive year-to-year goals, while the program also supports the broader industry with free resources such as guidance, tools, and case studies.
When the program began in 2019, it focused mainly on spreading awareness of embodied carbon and bringing structural engineers into the sustainability discussion, says SE 2050 co-chair, Lauren Wingo, P.E., M.ASCE.
“Now that people are aware, they’re changing their practice,” Wingo said. She has noticed more discussions around the time-value of carbon, where emissions saved today will exert a greater influence on the climate than the same amount of emissions saved in the future, in addition to the impacts of materials on embodied carbon.
“I think that (with) the industry standard now, you hear a lot of projects that are going to be looking at low-carbon concrete, for example, by default,” Wingo said. “And then maybe structural engineers are also using the case for carbon to justify a more efficient structural design.”
The scope of analyses
But just where engineers draw the line for what to include in their carbon analyses may steer decisions as much as the materials available or a project’s goals.
As an example of how the scope of an analysis can change its conclusions, Wingo pointed to some concrete mixes that use slag in place of cement to lower their carbon contents. While an individual project in the U.S. could lower its embodied carbon by using a slag-based concrete, such use necessarily makes that slag, a constrained resource, unavailable to projects in emerging economies elsewhere in the world, where reuse options, no-build options, or design efficiencies may be less practical.
“How do we think more deliberately about, ‘Do we need that big of a building? Do we need that building in the first place? Do we need that grid spacing?’ and those kinds of thoughts if you think more at the global emission scale rather than the project scale, which is right now what people are doing,” Wingo said.
For civil engineers looking ahead toward 2050, Lombardi seeks to flip what the industry considers conservative when choosing the scopes of analyses.
“Maybe you would use (a conservative argument) and say, ‘OK, we don’t know all of the information, so we’ll be conservative; we’ll focus on what we know,’” Lombardi said. “But actually, what we know is we can’t continue to do what we’ve done. So, in some ways, the least conservative thing is actually to go back to narrowing our focus. We need to step into this uncertainty.”
An economy-emissions-energy link
A robust, high-level link between economic activity, carbon emissions, and energy consumption could help engineers analyze the merits of carbon-reduction proposals and spot important externalities.
Proposed by J. Carlos Santamarina, Ph.D., M.ASCE, professor of geosystems engineering at Georgia Institute of Technology, who worked with Sinopec Tech Middle East LLC associate scientist Rached Rached, Ph.D., the relationship asserts that the three factors always move together while our energy mix remains based on fossil fuels. When assessing carbon-reduction strategies, a holistic view that examines spending, emissions, and energy could help engineers avoid incomplete life-cycle analyses up to the global scale, according to Santamarina and Rached.
“They’re all tied together very strongly with the relatively simple yardstick,” Rached said. “And what I found personally is that not many people are actually aware of this strong, strong connection. People typically see them separately: You have the energy, and then you have the emissions, and you have the economy, and these things kind of exist separately.”
A dollar of gasoline, for example, emits roughly 2.4 kilograms of carbon dioxide and delivers up to 2.7 kilowatt-hours of energy through a typical internal-combustion-engine car. The proportions roughly hold when applied to an economy-class airline ticket. But the dollar does not have to buy gasoline or plane tickets to emit carbon. One dollar spent in the global economy can be tied to the emission of roughly a quarter of a kilogram of carbon dioxide and more than 1 kilowatt-hour of consumed energy.
Although too coarse of an analysis for policy decisions or green-premium calculations, the yardstick can provide quick, order-of-magnitude checks on the merits of claims that might otherwise go unchallenged, Santamarina and Rached said. Where money is spent or where energy is expended, carbon is emitted.
“In a carbon-based economy, the emissions impact of a project is the project cost,” Santamarina said. “That is your best estimator to begin with.”
Global electrification
In 2025, the growth of worldwide energy demand slowed slightly, and a trend toward global electrification continued, according to the International Energy Agency’s Global Energy Review 2026, released in April. Driven by a range of uses in buildings and industry, electricity demand grew 3% in 2025, more than double the 1.3% growth of overall energy demand. Data center and electric vehicle power consumption, although still a small share of total growth, rose sharply, notably with data centers accounting for about half the demand growth in the U.S.
On the supply side, power generated from solar photovoltaics met more than 25% of the new demand, the first year in history that a modern renewable energy source satisfied the largest share of new demand. Together with wind, nuclear, hydropower, and other renewables, low-emissions sources met almost 60% of the growth in global demand.
Although the growth in energy-related emissions slowed, the amount hit a new high of 38.4 gigatons last year, driven mainly by natural gas combustion, and coincided with record carbon dioxide concentrations in the atmosphere.
The transition away from fossil fuels will paradoxically be powered by fossil fuels, Santamarina and Rached said. Returning to their spending-emissions-energy interdependency, the act of manufacturing and installing new solar panels, wind turbines, and other infrastructure will require energy, and if energy is used, carbon will be emitted somewhere.
“Most projections show fossil fuels remaining very important for decades,” Santamarina said. “In fact, the big petroleum companies are investing trillions of dollars to avoid supply shortfalls. It’s not because they are the bad guys; it’s because we need it.”
