Consistent normalization approach for Life Cycle Assessment based on inventory databases

Area of Science:

• Environmental Science
• Industrial Ecology
• Sustainability Assessment

Background:

• Life Cycle Assessment (LCA) uses a bottom-up approach, but lacks scale for environmental impacts.
• Current normalization methods rely on top-down approaches, leading to data inconsistencies and representativity issues.
• Existing normalization data can be inadequate for accurately contextualizing environmental impacts.

Purpose of the Study:

• To propose a novel, consistent approach for determining normalization reference data in LCA.
• To ensure consistency in boundaries, data sources, and modeling hypotheses for reference systems.
• To improve the adequacy and representativity of normalization data for environmental impact assessment.

Main Methods:

• Developed a novel approach for normalization data determination in LCA.
• Applied normalization as a ratio to the average component of the reference system, not the sum.
• Determined reference values using geometric means from inventory databases.
• Exemplary application to ecoinvent databases for impact categories and substances.

Main Results:

• Generated normalization references for 878 impact categories and 2077 substances within ecoinvent.
• Compared results across eight impact assessment methods with 16 literature normalization sets.
• Demonstrated highly significant correlations between the proposed method and existing normalization sets.

Conclusions:

• The proposed method provides consistent and representative normalization data for LCA.
• Geometric mean-based normalization enhances the reliability of environmental impact scaling.
• This approach offers a more robust foundation for comparative environmental assessments and decision-making.