Global Warming Potential (GWP) is a unit of measure for the embodied carbon in a product, expressed as kilograms of CO2e per functional unit.

Global Warming Potential (GWP) is a unit of measure for the embodied carbon in a product, expressed as kilograms of CO2e per functional unit.

• A. Kilowatt-hour
• B. Per square meter
• C. Litre of fuel
• D. Functional unit

Answer: (D)

In life cycle assessment, the amount of embodied carbon is tied to a defined function of the product. That defined function is the functional unit—the reference quantity used to compare different options that are meant to deliver the same service. By expressing GWP as kilograms of CO2e per this functional unit, you can fairly compare products that perform the same job but may have different designs or materials. The other options aren’t suitable as the reference for embodied carbon: kilowatt-hour is a unit of energy, per square meter measures area, and litre of fuel is a volume measure. None of those universally serve as the function-based reference for comparing carbon impacts across products.

In life cycle assessment, the amount of embodied carbon is tied to a defined function of the product. That defined function is the functional unit—the reference quantity used to compare different options that are meant to deliver the same service. By expressing GWP as kilograms of CO2e per this functional unit, you can fairly compare products that perform the same job but may have different designs or materials. The other options aren’t suitable as the reference for embodied carbon: kilowatt-hour is a unit of energy, per square meter measures area, and litre of fuel is a volume measure. None of those universally serve as the function-based reference for comparing carbon impacts across products.