The magazine in which this article first appeared—as well as almost everything around you, from the chair you’re sitting in to the building or park where you’re reading—represents embodied carbon. Fossil fuels have already been burned to create almost all man-made materials, and most of those products also contain carbon that could potentially escape to the atmosphere. As long as these objects and places remain intact, their carbon atoms are safely stored as usable matter, until a process such as combustion or aerobic decomposition in a landfill bonds them with oxygen to form the notoriously pesky greenhouse gas CO2.
“I like to think of embodied carbon almost like one of Newton’s Laws. Energy can’t be created or destroyed, it’s just transferred,” explains Karla Brent, an architect, sustainability expert, and project coordinator at the nonprofit Neighborhood Design Center. “Different amounts of energy end up going into the production of every material. But compare the intense fabrication process of metal to wood—a material that’s renewable; it comes from trees! I love that you can look at a piece of wood and understand where it came from. Plus, it stores carbon.”
This is a concept most tend to grasp at the scale of consumer goods, but seldom consider at the scale of the built environment. How many homeowners have forsaken single-use water bottles but still want a brand-new house wrapped in vinyl siding? Giving some TLC to Baltimore’s vast supply of already-built structures comprising energy-intensive materials, such as brick, and carbon-sequestering hardwoods, is one of the easiest ways to fight global warming locally.
“If you look at adaptive reuse projects, at least half of the building you need is already there,” Brent says. “The energy that was needed to build that was used years ago,” whereas new building projects require production and shipment processes that create pollution and consume raw materials. “Not to mention the added cost. When we have people who can’t afford to rent, they look elsewhere. In Baltimore, we have so many great old buildings that are no longer used for their intended purpose. We should be focused on restoring them.”