Perkins&Will’s David Cordell and Jon Penndorf explore how the A&D community can address embodied carbon to help combat climate change in the spaces they design.
The sources of carbon that fuels climate change range from automobile emissions to volcanic eruptions. But they also hide in plain sight, masquerading as benign construction and furnishing materials like gypsum board and carpeting. Inside the home or office, embodied carbon compromises the future of everyone and everything, from schoolchildren to the American bullfrog in Rock Creek Park. What is embodied carbon? It’s the total amount of carbon emissions released during a product’s manufacture, transportation, use and disposal.
Carbon, Carbon, Everywhere
Since the Industrial Revolution, carbon dioxide (CO2) has been pumped into the atmosphere from burning fossil fuels like coal and natural gas. Over the last century, it has accelerated from a concentration of between 200 and 280 parts per million (the norm for some 400,000 years) to a level well above 400 parts per million.
Enhanced by the synthetic chlorofluorocarbon molecules, or CFCs, that destroy the atmosphere’s protective ozone layer, the carbon molecules trap heat, alter the air that we breathe, and change both ecology and climate. The year 2020 was tied with 2016 as the warmest year on record, despite global shutdowns due to the coronavirus pandemic. Even though shutdowns have seemingly reduced the amount of carbon emissions in the past year, the overall concentration of CO2 has continued to increase. This is just one example of the climate change that has been linked to disastrous global stresses such as droughts, prolonged hurricane seasons, and wildfires.
Operational carbon, which comes from burning fossil fuels and releasing carbon into the atmosphere, is an obvious culprit. Less obvious, but equally impactful, is the contribution of embodied carbon. As an example, the embodied carbon calculation of the gypsum board commonly used to construct interior walls begins with the emissions released when gypsum is extracted from the earth. It continues through the emissions released in the manufacturing process, and the transportation from a factory or assembly line to a project location (factoring in, for instance, the truck fuel that moves it from one place to another).
The embodied carbon value increases again based on installation and the specific energy needed for on-site implementation. It also considers what occurs at the end of the material’s useful life—will the gypsum board be sent to a landfill where it will potentially off-gas as it slowly breaks down? In this case, the embodied carbon is often unseen and unrecognized because once installed, there is no operational energy expended on the walls that are made of the gypsum.
The choices we make in design and construction can have trickle-down effects on climate and weather patterns that are more apparent each year. Overall increases in global temperatures alone represent significant health risks for vulnerable populations like children and the elderly. Climate change also affects food supplies because of the impact on growing seasons for crops.
Altering global climate trends affects the ecology—when flora bloom and die—which influences both pollinators and migrations. It changes the chemical make-up of the atmosphere we share with dogs and frogs. The cascading consequences can be challenging to grasp as the changing climate’s impact on ecology may include species extinction, overpopulation of vermin, and lower air quality due to a lack of natural systems functioning as they have for centuries.
Variations in the atmosphere have also been directly linked to the increasing intensity of hurricanes, wildfires, and droughts worldwide. In the longer term, we see rising temperatures melt polar ice shelves. Much of the planet will be challenged by future sea level rise head-on as populations relocate and industries move from uninhabitable coastlines.
Human Health at Risk
Any changes in climate affect the basic determinants of human health: clean air, access to clean water, availability of nutritious food, and shelter. The shift in the global ecosystem is so dramatic, we are on the cusp of a new geological era in Earth’s history, already labeled the “Anthropocene Epoch” by some scientists. The name is derived from the Greek word anthropos, “human,” suggesting that humanity is a cataclysmic catalyst equal to the asteroid that wiped out the dinosaurs. Humans, however, don’t threaten ecosystems alone; our own health and the future health and prosperity of the next generation, is being put at dire risk.
In 2019, the medical journal The Lancet published a report stating, “A child born today will experience a world that is four degrees warmer than the pre-industrial average, with climate change impacting human health from infancy and adolescence to adulthood and old age”. The report forecasts a future for that same child that includes food scarcity and cumulative damage to their heart, lungs, and other vital organs from ongoing exposure to air pollution. All of this is compounded by regional climatic threats from wildfires, severe storms, floods, and emerging infectious diseases. Far from a fictional post-apocalyptic scenario, the estimated number of annual deaths from air pollution had already reached 7 million back in 2016.
The Next Chapter in Reducing Carbon
Fortunately, scientists agree there is time to change the arc of a disastrous narrative. Designing to reduce embodied carbon must play a major role. Architecture 2030 calculates that the building sector is responsible for about 40 percent of annual CO2 emissions worldwide. About 29 percent originates with the operation of buildings, but the remaining 11 percent comes from the embodied carbon in materials and the construction process.
The total embodied carbon of an interior fit-out can be reduced by prioritizing products with naturally low embodied carbon such as wood and selecting materials with manufacturing that has been optimized to reduce the amount of carbon generated. A focus on salvaged or reused materials drastically reduces embodied carbon because it eliminates emissions associated with new material harvesting and manufacturing. Such responsible decision-making can also tamp down CO2 emissions at the source.
What do these strategies mean for reducing greenhouse gas emissions, and how do we quantify the impact of specifying products with lower embodied carbon? According to the EPA’s Greenhouse Gas Equivalency Calculator, 6kg of carbon in the atmosphere equals the greenhouse gas emissions from driving a standard car 15 miles, charging 765 smart phones, or the amount of carbon sequestered by a single 10-year-old tree. That same tree converts CO2 into enough oxygen to support two humans every year.
We took a recent corporate interiors project and studied the embodied carbon impacts of the two main materials, ceiling tiles and carpet. Materials on this project were not chosen specifically to maximize embodied carbon reduction. Instead, they were selected based on performance across several criteria including cost, durability, lack of harmful chemicals in their manufacturing, and declaration of their environmental impacts.
The combined potential reduction associated with carpet and acoustic ceiling tiles for this project equaled about 3.5 kgCO2 per square foot. That doesn’t sound like a lot at first—just half of a tree according to the EPA’s numbers. But apply that math to a 30,000 square foot interior fit-out and suddenly you have 105,300 kgCO2e reduced. That is 261,000 miles not driven, or 1,740 trees.
A recent report from Cushman & Wakefield estimated that the nation’s capital saw approximately 3 million square feet of new leasing activity in 2020—not counting lease renewals or extensions. To be conservative, let’s assume projects achieve half the embodied carbon reduction from the calculation above. That still represents over 52 tons of CO2 reduction. That is the equivalent of 6,856 acres of forest producing a year’s worth of breathable air for 241,130 human beings, or approximately the population of Norfolk, Virginia.
Both federal and private scientific agencies have confirmed the patterns of global warming are real. While renewable energy will make a significant dent in operational carbon, the commercial design, construction, and real estate industry can no longer ignore the embodied carbon we inherently permit through the status quo. By addressing embodied carbon now, we seek to combat climate change for the benefit of the occupants and end-users of the spaces we design as well as for the greater planet. It’s a better story for all involved to tell.