Author: Patricia Alves
ABSTRACT: Embodied Carbon refers to all CO2 emissions associated with material and construction processes throughout the whole lifecycle of a building or infrastructure.
“Buildings are currently responsible for 39% of global energy-related carbon emissions: 28% from operational emissions, from the energy needed to heat, cool, and power them, and the remaining 11% from materials and construction” (Embodied Carbon Call For Action Report, n.d.). Because the world population is growing exponentially, the built stock is expected to double by the middle of the century. At the same time, technologies are being developed to reduce the operational emissions of buildings. Consequently, the numbers cited above are expected to change with upfront carbon to be responsible for half of the entire carbon footprint of new construction between now and 2050 (Embodied Carbon Call For Action Report, 2019).
There are great opportunities that can be acted upon before and during the construction of a building that can significantly reduce upfront emissions, it is important to be conscious and take actions in the early stages of designing because upfront emissions, differently from operation emissions, cannot be reversed once they are released and the construction is finished (Figure 1). Towards the goal of net-zero emissions, The World Green Building Council, with support from C40 Cities and Ramboll among others, released a report in 2019 to call for action. They envision that all new buildings, infrastructure, and renovations to have at least 40% less embodied carbon with significant upfront carbon reduction, and all new buildings to be net-zero operational carbon by 2030. And by 2050, new buildings, infrastructure, and renovations to have net-zero embodied carbon, and all buildings, including existing buildings, must be net-zero operational carbon.
Those are ambitious goals that will need a multidisciplinary approach. Everybody involved in the construction process must address their share of responsibility. Jennifer O’Connor (president of the Athena Sustainable Materials Institute) suggested tactics that different stakeholders can take at the Canadian Architects website. For example, manufacturers should find innovative solutions to produce environment-friendly materials, procure raw materials from sustainable sources and operate their facilities with fossil-free energy. Professionals like architects, engineers, and interior designers should be careful when making decisions about how to design, what to build, and even whether to build at all. They should also choose materials carefully, and work with clients to build awareness, and educate because clients are an important part of the decision process. Builders should make sure that all equipment on a construction site, as well as the equipment used for demolition and transportation, operate without fossil fuel. The government should also act, reviewing Building Codes to make sure there are no articles that inhibit the use of new sustainable products, and incorporate new techniques that contribute to the goal of net-zero emissions. The government could also require embodied carbon disclosure and introduce policies to put a price on embodied carbon, which would be a financial driver to stimulate builders and owners to comply.
“Most people do not realize that emissions due to material manufacturing, use, and disposal are responsible for a big upfront GHG pulse in a life of a building, making them a good near-term target for climate change mitigation” (O’Connor, 2020); as Interior Designers, there are some materials that we need to be more conscious of their carbon footprint. Concrete is the most abundant human-made material in the world and cement production (one of concrete’s components) is responsible for 6-10% of global anthropogenic carbon dioxide (CO2) emissions, making concrete the largest contributor to embodied carbon in the built environment (concrete, 2018). Alternatives already exist on the market, like the Limestone Portland cement that cuts embodied carbon by 10%, “PLC, or type IL cement, is a slightly modified version of Portland cement that can result in reduced embodied carbon by using higher percentages of limestone (5-15% in PLC, compared to the 5% typically used in Portland cement)” (The Advantages Of Portland-Limestone Cement, 2014), but avoiding prescribing concrete would be the desirable action; when it is not possible, its cement content should be specified strictly to the strength needed for the application (Park, 2020; Concrete, 2018). Steel is another material that should be used only when strictly necessary; for applications where the use of wood structure is not possible. Specifying steel from smaller manufactures that use electric arc furnaces, that can be powered by renewable energy sources, and has high levels of recycled content in their products, instead of from bigger manufacturers which facilities are powered by Basic Oxygen Furnaces (burn coal or natural gas in the process of making new steel that has low levels of recycled content) (Steel, n.d.) can be a good starting point towards a more environmentally friendly practice.
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Concrete. (2018, August 06). Retrieved February 23, 2021, from https://materialspalette.org/palette/
Embodied carbon call to action report. (2019, September). Retrieved February 23, 2021, from https://www.worldgbc.org/embodied-carbon
O’Connor, J. (2020, August 27). What can we do about embodied carbon?Retrieved February 23, 2021, from https://www.canadianarchitect.com/1003753921-2/
Pak, A. (2020, November 02). Embodied carbon: Key considerations for key materials. Retrieved February 23, 2021, from https://www.canadianarchitect.com/embodied-carbon-key-considerations-for-k ey-materials/
Steel. (n.d.). Retrieved February 23, 2021, from https://materialspalette.org/steel/
Patricia Alves has a previous medical degree from the University of Brasilia, Brazil, and a specialization as a radiologist. Currently in her fourth year of the Interior Design program at Ryerson University.