Urbanization has been both a gradual and cyclical process since the beginning of human civilization. However the rate of urbanization increased dramatically during the industrial revolution and evolved into “overflowing settlements” in the second part of the Twentieth Century. During this time, a post-World War II population boom in developing countries was largely absorbed by the cities. As a result, more than 50% of the world population now lives in the urban areas. This percentage is higher than 70% in Europe and this is why Arboriculture and urban forestry must have important roles in the management of urbanization and establishment of habitable cities. 

Greenspaces help cities reach the minimal thresholds for human well-being. Many view greenspaces simply as an outlet for recreation, however they can offer ways to improve citizens’ quality of life. These benefits have been the subject of numerous research projects, including European COST studies, the Horizon 2020 Programme for Research and Innovation, LIFE Programme, etc. Developing countries will also play an increasingly important role in global environmental issues as their major cities are growing much faster and often in a less sustainable way than those in the most developed countries. The presentation will summarize future arboricultural challenges identified at conferences, meetings, and research projects presently carried out all over the world. A particular focus will be on the ISA activities and program to become more and more international to realize the “arborization of the world”.