LCA and Biodiversity
Towards harmonized PDF and MSA units
By Anne-Claire Asselin
Life cycle assessment (LCA) has become the benchmark method for comparing the environmental impacts of products and services. Until now, when it came to biodiversity, the most widely used unit was PDF·m²·year (Potentially Disappeared Fraction of species, integrated in space and time).
A major breakthrough has been achieved by De Weert et al. (2025), who propose an LCA approach using MSA·km²·year (Mean Species Abundance) as an indicator of biodiversity loss, in consultation with the GLOBIO model development teams.
Why MSA?
- MSA is widely used in the ecology and biodiversity community (IPBES, global scenarios).
- It expresses the relative remaining biodiversity: 1 = intact ecosystem, 0 = lost biodiversity.
- By linking LCA flows (land use, climate, nitrogen, fragmentation, etc.) to GLOBIO dose-response functions, pressures can be directly converted into MSA loss.
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The importance of temporal integration As in conventional LCA, the new metric integrates area and duration of impact:
This approach allows pressures to be quantified in a realistic and cumulative manner. Conversely, an MSA measured “instantly,” without taking into account the duration of exposure, only reflects the specific state of biodiversity at a given moment and can give a misleading picture of the real impact of environmental pressures. |
LCA PDF vs. MSA GLOBIO : complementarity and coverage
- The PDF·m²·year, used in LCA, remains more comprehensive in terms of pressure coverage:
o It takes into account a wide range of pollutants (nitrogen, phosphorus, acidification, metals, etc.).
o It covers terrestrial and freshwater biomes, and even the marine environment for certain impacts such as eutrophication or ocean acidification.
- The GLOBIO MSA·km²·year focuses more on terrestrial pressures (land use, climate, nitrogen, fragmentation, habitat disturbance) and offers a point of convergence with global models and international assessments, but with more limited coverage of pressures.
Questions about non-temporal MSA Models
Some MSA approaches available in the literature or in public databases only provide point values, without integrating the duration of exposure to pressures. However:
- Biodiversity does not respond instantly to disturbances: cumulative effects build up over time.
- Measuring an MSA at a given moment may underestimate or overestimate the real impact, depending on the ecological dynamics and the duration of the pressures.
- Temporal integration is therefore essential for the MSA to become an operational indicator comparable to LCAs, such as PDF·m²·year.
A bridge between communities
- LCA already had a harmonized and comprehensive unit (PDF·m²·year).
- The MSA·km²·year offers an alternative that is consistent with global biodiversity assessments, facilitating dialogue between LCA practitioners, ecologists, and decision-makers.
- This convergence paves the way for more readable results that are better integrated into international biodiversity policies.
👉 In summary: yes, LCA in MSA is possible. The key contribution of the GLOBIO framework is to provide a spatio-temporal unit (MSA·km²·year) that captures the intensity, extent, and duration of pressures on biodiversity. The integration of time is therefore essential for the indicator to accurately reflect the magnitude of impacts and avoid biases associated with non-temporal MSAs, which only measure the instantaneous state of ecosystems.
Member of the European PEF (Product Environmental Footprint) Technical Advisory Board.
Member of the French ADEME environmental labelling working group.
