Embodied Carbon

What is embodied carbon?

Embodied carbon is the total amount of CO2e emitted during the production life cycle of a product. Embodied carbon – also known as embedded carbon – is primarily raw material extraction and refinement, manufacturing, and assembly. (Transportation typically only accounts for a low percentage of embodied carbon.)

The other main greenhouse gas (GHG) emissions category is operational carbon, which represents the amount of carbon dioxide equivalent (CO2e) emission emitted during the operational (in-use) phase of a building or product. This includes energy consumption, use, management, and maintenance of a product or structure.

Companies with the visibility to assess the carbon impact during product design and manufacturing can identify opportunities to reduce carbon often hidden due to this process’s complexity.

Sustainable manufacturing decarbonization strategies must consider the entire product development life cycle (embodied and operational carbon) to reduce a product’s environmental impact.

Why is embodied carbon becoming a larger percentage of GHG emissions?

The transition to a cleaner energy grid is accelerating as part of the effort to reduce climate change. The world’s renewable energy grew by 50% from 2023 to 2023, according to the International Energy Agency (IEA). This brought 510 gigawatts (GW) of renewable online in 2023, the 22nd consecutive year of added renewable capacity.

A greener energy grid, coupled with advances in electrification (e.g., electric vehicles replacing gas-powered cars), is reducing operational carbon. As such, embodied carbon is becoming a higher percentage of overall GHG emissions and is increasingly important to address. One-quarter of the global carbon footprint is embodied in traded goods, according to the U.S. Department of Energy Office of Science and Technical Information.

And this varies by industry. In the building materials and construction sector, embodied carbon will account for 49% of the total carbon emissions between 2020 and 2050, according to a United Nations (UN) report. To put this in perspective, nearly half of all CO2e for a building project is already released before its first tenants move in. (Embodied carbon in buildings is nearly 50% of its total CO2 e across its life cycle.)

Embodied carbon is far more complex to calculate than operational (in-use) carbon. And manufacturers require the ability to measure embodied carbon emissions in their design and production processes to help reduce global warming.

How can manufacturers reduce their embodied carbon emissions?

There are multiple ways that manufacturers can increase sustainability, including:

• Material selection:  Select low-carbon materials including recycled materials or bio-based alternatives to reduce emissions.
• Design for efficiency:  Engineer products to minimize material usage and maximize energy efficiency during use to lower embodied carbon and in-use carbon (e.g., the use of lighter materials for transportation products can reduce fuel consumption). Use manufacturing insights to assess the CO2e impact during the design phase, and conduct “what-if” scenarios to compare cost, sustainability, and manufacturability alternatives.
• Design for manufacturing: 
  • Consider manufacturing processes with low waste (e.g., plastic molding instead of machining, which can have a larger percentage of scrap).
  • Design products to minimize steps in the production process (e.g., eliminate the requirement for special tooling)
  • Enable low-energy manufacturing processes (e.g., minimize energy usage required for cycle time)
• Design for service and maintenance:  Address the need to simplify service during the in-use phase, and make it easier to access, recycle, and dispose of parts and components during the end-of-life phase.
• Energy mix for production:  Source manufacturing electricity from renewable sources to reduce emissions associated with production.
• Engineer for the circular economy:  Adopt initiatives including remanufacturing and refurbishment to extend a product’s life.
• Use life cycle assessment (LCA) data to guide decisions:  LCA assessments cover a product’s cradle-to-grave carbon footprint. Product design teams can review LCA assessments of similar, existing products for sustainability guidance. But due to the complexity of LCA data, it is not typically available to design teams to support new product development.
• Foster collaboration:  Share product sustainability data and collaborate with supply chain partners to reduce embodied carbon.

How is the building materials industry addressing embodied carbon?

Green building initiatives require companies to develop products that meet sustainability criteria. For example, many US communities require new buildings to have Leadership in Energy and Environmental Design (LEED) certification. Manufacturers of heating/cooling (HVAC) systems and other building materials/products need to provide sustainable products that will enable LEED certification.

Developers, in turn, are prioritizing sustainable products for the construction of their LEED-certified new buildings. To capitalize on the green building market, building product brands are securing environmental product declarations (EPDs) to demonstrate that their products support green building initiatives. An EPD is a product sustainability report validated by a third party that details product information (e.g., materials) and its GHG impact across its life cycle. A verified product EDP can provide developers with credits needed for LEED and related green building rating systems.