Climate Positive Design of the Exterior Built Environment
September 2023 | announcements
Image credit: Climate Positive Design
Following a nearly 20-year history of reshaping the conversation regarding the built environment’s contribution to climate change, Architecture 2030 is releasing new aggregations of International Energy Agency (IEA) data indicating that the global exterior built environment’s infrastructure and sitework impact has been underrepresented.
The global built environment is currently responsible for over 42% of annual global CO2 emissions.
Of those total emissions, building operations are responsible for 27% annually, while embodied emissions from just three high impact materials – cement, iron/steel, and aluminum – for buildings and infrastructure are responsible for an additional 15% annually.
As previously reported, in order to accommodate the largest wave of building growth in human history, from 2020 to 2060, we expect to add about 2.6 trillion square feet (241 billion square meters) of new floor area, doubling our existing building stock in just four decades¹. The need for upgrades and new infrastructure to support these buildings is staggering. In fact, 75% of the global urban infrastructure that will exist in 2050 has yet to be built².
The emissions from cement, iron/steel, and aluminum used for infrastructure are responsible for 7.3% of annual global CO2 emissions. Of those total emissions, cement emissions for infrastructure are responsible for 3.9% annually, while steel, iron and aluminum emissions for infrastructure are responsible for an additional 3.4%.
It is important to acknowledge that built environment impact is even greater than reported as the data does not factor in the additional emissions from other materials employed in buildings and infrastructure extending beyond cement, iron/steel, and aluminum. Additionally, neighborhood density, configurations, and services, including transit options that affect vehicle tailpipe emissions, originate from decisions made by architects, planners, and engineers. In fact, UN-Habitat reports that cities and their urban inhabitants are responsible for 80% of the world’s total greenhouse indirect and direct emissions.
Despite the fact that low carbon, nature-based solutions have been underutilized across all disciplines, the good news is that a shift is underway. While landscape architecture has long embraced these solutions, evident in ASLA’s Climate Action Plan and Field Guide, they are now gaining wide recognition among architecture and engineering organizations as well. This is evident in initiatives such as the AIA Framework for Design Excellence (Design for Ecosystems), USACE Engineering with Nature, and ASCE’s Infrastructure Report Card. According to the Nature Conservancy, these ecological interventions can provide up to 30% of cost effective carbon drawdown that is needed by 2030. Nature-based solutions support climate mitigation, and enable co-benefits related to human and environmental health, economic prosperity, and biodiversity.
To that end, Architecture 2030 and Climate Positive Design are collaborating to foster a comprehensive approach to addressing climate change impacts, carbon, and the exterior built environment (materials, buildings, landscapes, and infrastructure). We have recently launched new and updated resources and tools for design professionals, including content on concrete and steel in the Carbon Smart Materials Palette, calculating the carbon footprint and drawdown of landscapes in Pathfinder, and a wealth of design strategies in the Climate Positive Design Toolkit. By providing these comprehensive resources, we strive to empower design professionals in making more informed decisions.
In recent years, those working in the built environment sectors have come together to proactively take a leadership role in addressing climate change. Our collective efforts have resulted in remarkable progress, generating innovative and creative solutions that have led to climate-positive outcomes, zero operating emissions, adaptive, resilient buildings, infrastructure, and communities.
Our collective commitment goes beyond short-term gains; it is a long-term dedication to creating an equitable, sustainable legacy, where cities are designed to reverse the current declines in biodiversity, while fostering thriving communities that engage and integrate with the natural world.
Designers wield significant influence and carry substantial responsibilities, ranging from macro-level planning and land use decisions to micro-level material selections. The ongoing connection and integration of design professionals across disciplines such as architecture, landscape architecture, planning, and engineering are already underway and crucial for the successful execution of large and complex projects. Fostering collaborative efforts within the built environment community, spanning all scales, will contribute to shaping a sustainable future for the entire built environment.
¹ International Energy Agency, “Global building sector CO2 emissions and floor area on the Net Zero Scenario, 2020-2050”. 2060 floor area assumes projected trends would continue.