Nano and micro level circular economy indicators: Assisting decision-makers in circularity assessments

The growing interest for Circular Economy (CE) urged experts to develop assessment metrics regarding the shift from a linear to a circular rationale. As a response, the recent literature has been populated with a plethora of circularity indicators addressing different CE scales: nano (products), micro (companies), meso (industrial symbiosis), and macro (governments). However, simply shifting to circular systems does not necessarily result in favorable alternatives, as trade-offs may occur concerning environmental, economic, or social impacts. In order to assist decision-makers in the processes of choosing the best suiting indicator for circularity assessments, this study presents a systematic literature review aiming at nano-and micro-level indicators, which were evaluated according to their relation to the sustainability pillars and life cycle stages (take, make, use, recover). Sixty-one publications were analyzed (44 peer reviewed, 16 from gray literature, 1 dissertation). Fifty-eight indicators were explored (38 nano, 14 micro, 6 directed to both levels). Findings show that the majority of metrics are nano-level environmentally driven indicators that focus on material and resource recovery strategies. A second expressive group is simultaneously focused on the environmental and economic pillars. Social repercussions are rarely addressed. We argue that the analyzed indicators mainly focus on material and resource recirculation and lack robustness to assess the sustainability performance of circular systems. Future research could analyze the integration of the investigated indicators with consolidated methodologies to overcome the barrier of combining circularity and sustainability performance. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

The growing interest in Circular Economy has led to the development of assessment metrics, but there are still challenges in choosing the appropriate circularity indicators. Current focus is mainly on material and resource recovery strategies, with social impacts being addressed less frequently.