Resumo:
Historically, urban development has followed a linear model in which natural resources are extracted, used, and subsequently discarded, a characteristic of so-called Linear Cities (LC). This model is unsustainable, prompting cities to rethink their operations and make better use of resources. In this context, the principles of Circular Economy (CE) have been incorporated at the urban scale, giving rise to the concept of the Circular City (CC), also known as urban circularity. CCs implement CE guidelines, adapt their structures, regenerate natural systems, and promote local production and consumption to improve resource management and achieve sustainability. However, cities seeking to become circular, mostly located in Europe, face challenges in planning and implementing circular solutions. In the Brazilian context, where the transition is still in its early stages, these challenges are even greater, particularly given the need to identify existing practices that align with CCs. Given this, the present study aims to develop a decision-support tool to assist in the sustainable urban circular transition. The proposed tool, named CIRCCITY (Circular City Transition Tool), was developed using the Design Science Research (DSR) approach. CIRCCITY is structured into three components. The first component is a maturity model structured into four levels (Level 0: Linear City; Level 1: Waste Management; Level 2: Circular Economy; and Level 3: Circular City), which enables identification of the current stage of the circular transition. The second component is a set of indicators to monitor the results of circular actions in key sectors (Waste, Agriculture and Food, Local Production and Industry, Energy, Mobility and Transportation, Water and Sanitation, and Space and the Built Environment). The final component consists of a set of indicators to assess economic, social, and environmental impacts. The tool was applied in the city of São Paulo, which scored a Maturity Level of 1 (Waste Management), indicating that efforts remain focused on recycling and energy recovery. Although the city seeks to promote circular business models, these actions remain fragmented. São Paulo needs to make progress in implementing strategies to prevent waste generation and change consumption patterns. Furthermore, the results indicate the need to implement regenerative and adaptive practices in its infrastructure to enable better resource circulation. Thus, the use of the tool demonstrated its effectiveness in supporting public managers at different stages of the circular transition, establishing itself as a structured instrument for decision-making support. Finally, the tool is available on a free digital platform, accessible to urban managers across cities, thereby contributing to the dissemination of knowledge and the advancement of sustainable urban circularity.