GHG Emission Factor

Definition

A GHG Emission Factor is a factor (multiplier) that converts activity data into GHG emissions data. Emission factors are positive for produced emissions and negative for sequestered emissions.

A physical emission factor is the emission factor associated with a Physical Activity. The unit depends on the type of activity. Two types of emission factors can be used for calculating emissions associated with a material or product:

• Life cycle emission factors, which include emissions that occur at every stage of a material/product’s life, from raw material acquisition or generation of natural resource to end of life
• Cradle-to-gate (sometimes referred to as “upstream”) emission factors, which include all emissions that occur in the life cycle of a material/product up to the point of sale by the producer.

An economic emission factor is the emission factor associated with an economic activity. These economic emission factors can be structured in different ways based on the underlying datasets that are used. Most often, there are different economic emission factors available for different countries/regions and sectors.

Examples

• kg CO2 emitted per liter of fuel consumed, or
• kg CO2 emitted per kilograms of material produced
• tCO2eq/tonne crude oil
• -200 tCO2eq/hectare forest and
• 100 gCO2eq/kilometer driven.