For whom are these trees? Dynamic scenarios of urban greening for climate regulation in dense urban contexts with high resolution thermal comfort simulations

Urban ecosystems are vital providers of services in cities, particularly playing an essential role in regulating the urban microclimate and mitigating the Urban Heat Island effect. The quantity, location, and spatial arrangement of green infrastructure are crucial factors for urban planners and designers aiming to maximize climate regulation potential, thereby extending these benefits to a larger number of residents and city users. Various factors and constraints influence the cooling effects of green infrastructure and the extent to which these effects can benefit both urban spaces (e.g., streets, sidewalks, squares, parks) and the people who regularly use them. This paper explores the relationship between benefits and beneficiaries by identifying and simulating high-resolution scenarios of new urban greenery that maximize cooling benefits for residents and users. In the case study of a hot and dry Mediterranean metropolitan area -the city of Catania, Italy-greening scenarios are proposed and simulated by modeling physical and socio-economic factors as spatial constraints for placing new elements of green infrastructure. First, scenarios are identified and simulated using the UMEP model to evaluate the outdoor thermal comfort of the simulated scenarios; second, the potential beneficiaries are quantified with dynamic GIS-based kernel density analysis of the most relevant urban functions and activities. Finally, the effectiveness of the greening scenarios is quantified as a combination of the increase in outdoor thermal comfort and the number of potential beneficiaries who can enjoy it. Results show that the new elements of green infrastructure should be located in public areas that are most used and that cooling benefits can be extended to different parts of the public space during the daytime, depending on the spatial configuration of urban morphology.