What is Embodied Carbon?

In the fight against climate change, efforts are intensifying against the planet’s number one enemy – carbon dioxide. With respect to a building, there are two types of carbon emissions: operational carbon and embodied carbon. In this blog, we’ll be focusing on embodied carbon and why it is so important to focus on reducing it.
Embodied carbon: Carbon dioxide emitted during the manufacture, transport and construction of building materials.
Operational carbon: Carbon emitted during the operation of building, i.e.  heating, cooling, water use, lighting, fans, pumps, electricity and appliance use.
Embodied carbon refers to carbon dioxide emitted during the manufacture, transport and construction of building materials. Dire warnings from climate scientists are putting pressure on the building community to make sustainable changes. Traditionally, these changes focused on operational carbon, but recently, embodied carbon has been gaining attention as new construction continues to expand.
Embodied carbon emissions are fixed in place as soon as a building is complete, and can’t be improved upon once the building is finished. This is in contrast to operational carbon emissions, which can be reduced over time with efficiency renovations and the use of renewable energy. Therefore, industry professionals need a proactive plan to reduce embodied carbon emissions as reductions cannot be made later.

Carbon Life Cycle of a Building

Life Cycle Analysis (LCA) is an important way to assess the sustainability of new building construction, as well as the carbon cost of maintaining, demolishing, or refurbishing existing buildings.

As you can see from this graphic, Operational Carbon only makes up a small percentage of a building's life cycle (Operation).  The Embodied Carbon that comes from extraction, transportation and manufacturing of raw building materials is a significant part of a building's life cycle.
Embodied carbon will be responsible for almost half of total new construction emissions between now and 2050.
Embodied Carbon Vs Operational Carbon
According to Architecture 2030, the building sector produces approximately 40 percent of annual global carbon emissions, with embodied carbon (in the form of materials and construction) accounting for  11 percent of global greenhouse gas emissions. While we cannot stop new construction, we can address embodied carbon throughout the process. For any new building, all stakeholders should consider ways to lower embodied carbon.
For example:
  • Select lower carbon alternatives: Some materials, like concrete, are known for their emissions. A ton of cement (the main ingredient in concrete) represents about a ton of greenhouse gas emissions. Instead, select materials with a lower carbon footprint.
  • Use whole-building life-cycle-assessments to understand the impacts of building materials over their entire life cycles.
  • Choose materials from local sources: Generally, the shorter distance a material travels, the lower its embodied emissions will be. However, not all transport is equal, and the method of transportation may have an impact.
Between now and 2060, the world’s population will be doubling the amount of building floorspace; that’s the equivalent of building an entire New York City every month for 40 years. 
With this massive increase in construction, we see the urgent role embodied carbon plays. The construction industry should be ready to adapt existing solutions and find new ways to reduce embodied energy as new construction accelerates across the globe.