Progressive urbanization and population migration to cities have made these settlements less resilient, unsustainable, and unable to guarantee an adequate quality of life. Today, cities are not only the largest consumers of natural resources and emitters of pollution, but also the places where climate change and the urban heat island phenomenon are having the greatest impact, as evidenced by recent environmental statistics. Beyond being places of development, cities have progressively become places where humans encounter a series of pathologies with specific connotations. Can urban greenery help reverse this trend? This report summarizes the state of the art of research in this field and how it is possible to create more human-scale cities, improving people's health and well-being. Specifically, the report explores how new disciplines or applications have emerged in recent years and how the use of appropriate urban tree vegetation can mitigate the effects of pollution and climate change. This urban greening is only possible through an interdisciplinary approach. Forest sciences can contribute their expertise to more sustainable urban planning. This process of planning and monitoring cities, in particular, requires new indicators that take into account not only the simple extent of green spaces, but also the volume of tree canopies, which are one of the most important providers of ecosystem services.