Global characterisation factors to assess land use impacts on biotic production

Purpose The inclusion of land-use activities in life cycle assessment (LCA) has been subject to much debate in the LCA community. Despite the recent methodological developments in this area, the impacts of land occupation and transformation on its long-term ability to produce biomass (referred to here as biotic production potential - BPP) - an important endpoint for the Area of Protection Natural Resources - have been largely excluded from LCAs partly due to the lack of life cycle impact assessment methods. Methods: An overview of existing methods/indicators associated with biomass, carbon balance, soil erosion, salinisation, energy, soil biota and soil organic matter (SOM) were evaluated. The latter indicator was considered the most appropriate, and characterisation factors for 8 land use types at the climate region level were developed. Results: Some indicators address land-use impacts satisfactorily for land uses that include biotic production of some kind (agriculture or silviculture). However, some fail to address potentially important land use impacts from other life cycle stages, such as those arising from transport. It is shown that the change in SOC can be used as an indicator for BPP, which combines and relates to a range of soil properties responsible for fertility into a stand-alone indicator. Conclusions: The results suggest that the proposed approach to characterize land use impacts on Biotic Production Potential, despite its limitations, is both possible and robust. The availability of land-use specific and biogeographically-differentiated data on SOC makes BPP impact assessments operable. The characterisation factors provided allow for the assessment of land-use impacts on BPP, regardless of where they occur. This is a new development in the LCIA of land use. Existing databases on every country's terrestrial carbon stocks and land use enable the operability of this method. Furthermore, BPP impacts will be better assessed by this approach as increasingly spatially-specific data are available for all geographical regions of the world at a large-scale. The resulting information would enable better life cycle assessments of products and services, as the important issue of the land use impacts on BPP can be captured. The characterisation factors developed are applied to the case studies (Part D of this special issue), which show the practical issues related to their implementation.JRC.H.8-Sustainability Assessmen