An agent-based model to foster citizens’ sustainable behavior in the Italian city of Siena

Climate change is irreversibly having an increasing impact on the environment, people and the economy worldwide. The contribution of each individual in counteracting its effects is crucial, as everyday actions, from a proper participation in waste sorting to responsible consumption choices, can shape a more resilient and environmentally friendly future. How much do the geographical and urban features of an Italian art city impact the spread of sustainable behaviors among its citizens? In this paper, we investigate the climate awareness and attitudes toward sustainability of citizens living in the historical center of Siena, a small art city among the most sustainable in Italy. Using a geo-referenced agent-based model (ABM) and game theory for the human decision-making process, we simulate how pro-environmental attitudes spread in a population of predominantly selfish individuals and in which there are also herding and anti-herding mechanisms. We claim that on the one hand, the conformation and geographical position of the city of Siena make it naturally sustainable, but at the same time its urban structure and connection networks seem to limit the spread of cooperative actions toward environmental protection. Graphic abstract: (Figure presented.)