Embodied carbon is one of the most pressing matters in the fight against climate change. It is the footprint of all steps involved in material production, which includes sourcing, extraction, manufacturing, and maintenance.
In the building industry, of the three most common materials (steel, concrete and wood), steel and concrete production emit a large portion of the world’s greenhouse gasses (GHG). While it is possible to reduce the operational carbon footprint of a building (all-electric, more efficient heating systems, water recycling systems, renewable energy production…) - greenhouse gas (GHG) emissions from the materials needed to make these buildings can not be reversed.
The right material consideration can help reduce embodied carbon. Wood-based walls, for example, entail 10-20% less GHG emissions than concrete based walls - which have lower embodied carbon than steel based wall systems.
There is also future hope for reducing our use of raw materials altogether. This can be achieved with a circular economy, a system that favors the preservation of energy starting from labor to the materials used. This requires keeping components circulating in the economy. Although the process is appealing, it can also be problematic since it counts on choosing the right recycling technology. But how would we know if the materials were recycled efficiently?
Whether using raw or recycled material, it can be difficult to have access to this type of information since it relies on material producers' transparency and accountability.
The Embodied Carbon in Construction Calculator (EC3) is a database that aids in keeping building material carbon impact information transparent. EC3 is a collaborative project which allows producers, like concrete producers, to publish specific information, known as the environmental product declarations (EPDs). Similarly, there are other databases like the health product declarations (HPDs) which publish specific toxicity of ingredients used in producing materials.
The positive news is that this topic is gaining momentum and great strides are taking place. There are many collaborations like Architecture 2030 and the Climate Positive Design Challenge, a research collective action working towards a more sustainable built environment. To learn more please see these resources:
Climate Positive Design Challenge: https://climatepositivedesign.com/challenge/
The 2030 Challenge: https://architecture2030.org/the2030challenges/
Health Product Declaration Database: https://www.hpd-collaborative.org/hpd-public-repository/
EC3 Tool: https://www.buildingtransparency.org/
Carbon Smart Materials Palette: https://materialspalette.org/
Embodied Carbon Material Comparison Article with Resources: https://blogs.umass.edu/natsci397a-eross/what-building-material-wood-steel-concrete-has-the-smallest-overall-environment-impact/
Capture Recycled Carbon in Concrete: https://www.carboncure.com/