Biodiversity Assessment of Value Chains: State of the Art and Emerging Challenges.

The consumption of materials and products is one of the drivers of biodiversity loss, which in turn affects ecosystem functioning and has socio-economic consequences worldwide. Life cycle assessment (LCA) is a reference methodology for appraising the environmental impacts of products along their value chains. Currently, a generally accepted life cycle impact assessment (LCIA) framework for assessing biodiversity impacts is lacking. The existing LCIA models present weaknesses in terms of the impact drivers considered, geographical coverage, as well as the indicators and metrics adopted. Sound ecological indicators and metrics need to be integrated in order to better assess the impacts of value chains on biodiversity on a global, regional, and local scale. This review analyses studies which, using a life cycle perspective, assess the impacts of products' and services' value chains on biodiversity. We identify and discuss promising synergies between the studies which look beyond the life cycle context, and apply other biodiversity metrics. Our results highlight that the existing metrics of biodiversity impact assessment in LCA are poor at capturing the complexities of biodiversity. There are operational models at the midpoint level that expand on the assessed dimensions of biodiversity (e.g., ecosystem structure), and the drivers of biodiversity loss (e.g., assessment of species exploitation), but efforts are required to fully include these models in the LCA framework. In the business domain, many initiatives are developing frameworks to assess impacts on biodiversity. Many approaches make use of LCIA methods and input-output databases. However, these are generally coupled with other biodiversity metrics. This shows that the current LCA framework is not yet sufficient to support decision-making based on different sets of biodiversity indicators. Ecosystem accounting may provide important ecological information for both the inventory and the impact assessment stages of LCA, helping to disentangle the relationship between biodiversity and ecosystem services. Looking beyond the LCA domain can lead us to new ways of advancing the coverage of biodiversity impacts, in a way that increases the relevance of LCA across a wider range of areas. Future work should assess the indicators provided in various policy contexts.