Résumé
AbstractPurposeThe integration of ecosystem services into the impact assessment phase, through the development of characterization models that reflect potential impacts on ecosystems’ capacity to provide services, is gaining momentum within the life cycle assessment community. This integration requires reflection on the positioning of concepts related to ecosystem services such as ecosystem functions, ecosystem services potential and flow within the life cycle impact assessment framework and in relation to common indicators. This research posits that the concepts linked to ecosystem services are at the crossroads of most characterization models, and proposes a revamped vision of the conceptual life cycle impact assessment framework. Its use is exemplified for the IMPACT World+ methodology.MethodBuilding on the areas of protection proposed by Verones et al. (2017), the framework introduces a revised “Ecosystem Services” area of protection, which aggregates potential impacts on the instrumental value of social-ecological systems. Here, the term “Ecosystem Services” follows the Common International Classification of Ecosystem Services (CICES v5.2) and is used as an umbrella concept encompassing both biophysical ecosystem services and geophysical ecosystem outputs, noting the deviation from definitions of “ecosystem” provided by the UN’s Convention of Biological Diversity and some ISO standards.Results and discussionThe revamped life cycle impact assessment framework is structured around the ecosystem services “cascade model”. It identifies causal pathways linking human activities to changes across different stages of the cascade and, ultimately, to the areas of protection. The framework considers the consequences of replacement strategies in response to declining services flows: replacement costs, indirect impacts associated with boundaries’ expansion, deficit of services, and potential impacts on human health. Existing characterization models from the IMPACT World+ methodology are mapped within this new structure. The framework reconciles natural resources- and ecosystem services-oriented characterization models, helps identify priorities for the development of characterization models in the IMPACT World+ methodology, and offers perspectives for integrating ecosystem disservices into life cycle impact assessment.Conclusion and recommendationsBy rethinking the life cycle impact assessment structure through the perspective of ecosystem services and related concepts, this work establishes a conceptual basis for the development of more coherent, comprehensive, and operational life cycle impact assessment models and methodologies.