Moving Towards a Holistic Approach to Circular Cities: Obstacles and Perspectives for Implementation of Nature-Based Solutions in Europe

Nature-based solutions (NBS) are frequently implemented without taking the system's perspective into account and with the main focus on technical and economic issues of implementation. This study was conducted to test the hypothesis on the potential synergistic effects between circularity and NBS to holistically tackle urban challenges. The main objective is to establish preliminary insights on the obstacles and perspectives of NBS integration and implementation, through a questionnaire set up by the network of experts gathered within the COST Action CA17133 Circular City. The following research questions arise: (i) what differences exist in the level of NBS application according to the variance of engaged countries; and (ii) what are the main obstacles and perspectives for the NBS implementation in order to holistically tackle urban challenges, enhancing the sustainable connection among urban environment, nature, and human well-being. To go beyond the current state-of-the-art and reflect on the research conducted within the Circular City Action, this study aims to open a multi-geographical academic dialogue across Europe and beyond and to move towards a holistic approach to circular cities. Accordingly, this study is: (1) multi-geographical and context-based, providing input for thirty-three EU countries and four non-EU countries to give an overview of the main obstacles and perspectives of NBS implementation, and (2) approach-directed, aiming to formulate a holistic approach to deal with societal challenges. This document intends to provide qualitative and quantitative insight into the potentials and obstacles of NBS implementation in Europe, as well as to motivate further discussion and research to achieve holistic and sustainable cities.