Scientific research conducted by ENEA and published in ‘The Lancet Planetary Health’ shows that increasing the number of trees in cities considerably improves air quality and citizen health. Just five additional trees per 100 people is enough to have a significant impact on urban well-being. This finding is supported by the experience of KilometroVerdeParma, a project of the eponymous Forestry Consortium that planted over 100,000 trees in five years. Cleaner air, reduced pollution concentrations, and softer temperatures during hot summers are just a few of the advantages uncovered by a survey of 744 cities across 36 European countries. Increasing tree cover has been identified as one of the most effective approaches for safeguarding public health and improving quality of life. The study also emphasizes the transformative potential of urban forestry: by planting just five trees per 100 people, cities might significantly improve their environmental quality and citizens' quality of life. The survey compared many Italian cities: Rome has 24% tree cover, Milan has 9%, and Naples has more than 30%, demonstrating how many urban regions are still far from meeting ideal levels for broad well-being.