When people think of climate change, they tend to picture smokestacks, tailpipes, or high-rise buildings. They rarely think of the bridges we cross, the tunnels we pass through, or the roads that hold our cities together. Yet cement, steel, and asphalt are among the most carbon-intensive materials in the global economy. The World Green Building Council reports that buildings and construction together account for roughly 39 percent of global energy-related carbon emissions, with approximately 11 percent attributable to embodied carbon (the emissions locked into materials during extraction, manufacturing, and transport). Once a bridge is poured or a tunnel is lined, those emissions are fixed, demonstrating the difficulty of decarbonizing infrastructure.

As a structural engineer, I encounter this gap in practice when decarbonizing infrastructure. When I specify materials for bridges and structural systems, I know that the carbon consequences of those choices are fixed the moment concrete is poured or steel is erected. For most of my career, embodied carbon was not a standard part of design conversations. That is beginning to change, not because of any single technology, but because of coalitions: Groups of actors who do not typically work together, finding ways to align around a shared problem when decarbonizing infrastructure.

Infrastructure decisions and decarbonizing infrastructure shape which communities bear the greatest burden of carbon-intensive construction and which gain the resilience benefits of forward-looking design. But reducing embodied carbon in infrastructure is not a narrow technical problem. It is a systems challenge at the intersection of procurement, materials science, community development, and public finance. When a state agency requires decarbonizing infrastructure with lower-carbon materials in public works, it simultaneously shifts supply chains, changes how engineers specify products, and creates opportunities for manufacturers who have invested in cleaner production. When a city mandates pre-demolition salvage audits, it connects environmental goals with local employment in deconstruction and reuse. When engineering firms benchmark their embodied carbon performance against peers, they create professional norms that ripple across thousands of projects.

Read the full article about decarbonizing infrastructure by Prateek Srivastava at Stanford Social Innovation Review.