LCA based circularity indices of systems at different scales: a holistic approach.

Many are the definitions of Circular Economy as well as the policies and strategies for its implementation. However, gaps still exist in quantifying the effects of circularity. The existing approaches are usually sector- or product-specific, limited to microscale systems, and/or fail to simultaneously assess the environmental impacts of the studied system. This paper introduces a generally applicable method in which a set of LCA-based indices of circularity are able to detect the effects of circularity/symbiosis strategies on the environmental performance of meso- and macro-systems. These indices quantify the overall system's circularity level by comparing the impacts of a system in which the components interact with each other (with a certain level of circularity) with an equivalent linear system (where no circularity takes place). The method works both on existing and projected systems, being able to track the effects of future circularity policies. This method obviates the limitations and the gaps mentioned above: it applies to meso- and macro-systems, it is not bound to a specific sector, it allows to capture the environmental impacts, and it is sensitive to the temporal dimension. This approach provides a tool to inform managers and policymakers for planning circularity actions and monitor their effectiveness while also capturing the temporal dimension.