The urban built environment is responsible for approximately 75% of greenhouse gas emissions. As building professionals tackle this challenge, a tremendous opportunity for impact lies, quite literally, outside the box of the buildings themselves: in the exterior built environment of site, landscape, and infrastructure. Although we often overlook these elements as major carbon contributors, the emissions drawdown and carbon sequestration opportunities are immense.
Climate Positive Design is an initiative dedicated not only to understanding the potential that site, infrastructure design, and urban planning have to reduce emissions and sequester carbon, but also to igniting a powerful set of co-benefits, such as resilience, improved water quality, biodiversity, and human health. Built and natural landscapes are complex, living ecosystems that change and evolve. Until recently, however, the carbon impacts of sites and infrastructure have been overlooked. If we pay attention to the design of the exterior built environment—such as material selection, project operations, overall low-carbon, green infrastructure approaches that draw down carbon—emissions can be cut in half (or more), and sequestration can be doubled.
I launched the Climate Positive Design Challenge and the Pathfinder app to guide designers of the exterior built environment to improve the carbon performance of sites, and I’m expanding that work in partnership with Architecture 2030. Our collaboration will strive to deliver accessible tools, resources, and guidance to professionals and industry organizations responsible for planning and designing the exterior built environment to achieve the drawdown needed to meet the 1.5°C climate target. With targeted guidance and thought leadership, the initiative will empower the exterior built environment sector to reduce CO2 emissions dramatically, sequester more carbon than emitted by 2030, and remove 1 gigaton of CO2 from the atmosphere beyond offsetting emissions by 2050. Specific approaches include urban afforestation, habitat restoration, and habitat creation including constructed wetlands and the use of native and drought-tolerant plant species. These nature-based solutions can improve health through better air and water quality and offer protection from the adverse effects of climate change, such as drought, flooding, sea-level rise, and wildfires.
By combining our knowledge, leadership, and networks, we are issuing a call to action to the most influential firms and professional organizations in the architecture, landscape architecture, and urban planning professions: We cannot ignore the exterior built environment. We will support their efforts with tools, guidance, and resources to enable projects that sequester carbon—and we want and need their support, too. If your firm designs places outside the building, take the Climate Positive Design Challenge and support the International Federation of Landscape Architects Climate Action Commitment. Or, if you work with landscape architects and planners outside your firm, you can all use the Pathfinder app for your site designs. And you can urge those professionals to sign up for the challenge as well.
Every person and organization in the built environment community can take climate action beyond the building—an effort that requires this broader perspective to reach emissions drawdown in our sector. For every on-the-boards project, the built environment team can optimize value and benefits with these strategies for sequestration and resilience. Will you join us?
This article first appeared in the ARCHITECT 's July/August 2022 issue.