Sustainable cities sounds like the future. Low carbon emissions and no cars in the city center so the air is fresh. Humans benefit from living among trees. The

Sustainable cities sounds like the future. Low carbon emissions and no cars in the city center so the air is fresh. Humans benefit from living among trees. The value of trees can be seen of property prices in New York where central park is highly valued. http://www.newyorker.com/tech/elements/what-is-a-tree-worth http://www.newyorker.com/tech/elements/what-is-a-tree-worth