Trees, well-being and urban greening

There are approximately 3 trillion trees worldwide. Forests range the globe in tropical and subtropical, temperate and boreal regions and in cities the percentage of land covered by trees exceeds 20% in some of the greenest cities in the world: Singapore, Sydney, Vancouver, Johannesburg and Frankfurt (MIT Senseable City Lab., 2018). Trees have a positive impact on human health and well-being through multiple services including carbon sequestration, timber production, places for recreation, shade to protect from heat and air purification. However, an estimated 15 billion trees are cut down each year (based on 2000–2015 trends), and the global number of trees has fallen by about 46% since the start of human civilization (Crowther et al., 2015). This chapter outlines some examples of how trees benefit human health and well-being and shows why the role of trees in urban planning and their value as natural capital should be considered important to planetary health.