A normalisation reference is the amount of an Impact category indicator for a specific Activity or group of activities that is a baseline for comparison in Life Cycle Assessment. This reference value is typically calculated as the aggregated per capita production or consumption for a defined geographical area over a specified time period, usually one year.
The purpose of a normalisation reference is to provide context and scale to Life cycle impact assessment result values. By comparing an LCIA result to a normalisation reference, practitioners can express environmental impacts in relative terms rather than absolute units. For example, a carbon footprint might be expressed as "equivalent to 0.01% of the annual per capita greenhouse gas emissions in the European Union".
Normalisation references are constructed by aggregating impact category indicator amounts across all relevant activities within a geographical boundary, such as a country, region, or the entire world. The total impact is then divided by the population to obtain a per capita reference value. This approach allows for meaningful comparisons between product systems and provides insight into the relative contribution of a specific product or service to the total environmental burden of society.
Common geographical scopes for normalisation references include individual countries, regions such as Europe, or global averages. The choice of normalisation reference can significantly influence the interpretation of results, as different geographical areas may have varying levels of production, consumption patterns, and environmental pressures. The normalisation reference should therefore be appropriate to the decision context, and clearly communicated when presenting results.
As Chief Operating Officer, Iris leads our organisational development and oversees day-to-day operations. Before joining 2-0, she worked in the biotechnology sector. As an LCA consultant, Iris has devoted her expertise primarily to the domains of sustainable agriculture and food production. She is dedicated to teaching LCA and is responsible for our educational efforts. Iris holds an M.Sc. in Biology – Biotechnology from the University of Copenhagen.
Contact for: LCA Training
Glossary terms are clearer once you have seen them applied. Our guide to what LCA is and how it works walks through the complete methodology: goal and scope, inventory modelling, impact assessment, and interpretation.
If you are working on an LCA study and want it done properly, see how we approach life cycle assessment.
