The role of citizens and transformation of energy, water, and waste infrastructure for an intelligent, sustainable environment in cities

Purpose This study aims to list indicators to allow construction of a ranking for environmental sustainability in towns and cities, in relation to energy and water consumption and the prevention, production and management of waste. A systematization of theoretical and empirical indices was elaborated, focused on this dimension. Design/methodology/approach The results allow presentation of a ranking supported by multivariate statistical techniques - Exploratory Factor Analysis and Principal Component Analysis - confirming its scientific quality and robustness, with this being the main contribution of the study. Findings The analysis of the ranking revealed the great heterogeneity of towns and cities in Portugal, with the city of Lisbon and the town of Sardoal in the Top 20, suggesting that the achievement of the goal of environmental sustainability is proactively associated with the ability to articulate resources with infrastructure and the strategic and political will applied, being essential the appeal to the individual awareness of each citizen, even if the design of green infrastructures does not depend on citizens' behavior. This means that redesigned green infrastructures may exist, but their success depends. In addition, cities are increasingly moving toward a circular economy articulated holistically with open and participatory governance. Practical implications The empirical evidence obtained in the Portuguese context provides some implications for practice, by showing it is possible to counteract the negative effects of rapid urban growth and its environmental consequences in urban and non-urban areas. Originality/value The main contribution and innovation of this study lie in the presentation of empirical evidence that the population density of a city or town does not have a cause-effect relationship with its level of environmental sustainability.