A Shell representative said “Urbanisation represents the biggest social and demographic disruption of the early 21st century. Hundrets of millions of people move out of poverty for the first time. This stresses resources. Cities are the places where these stresses aggregate.
Applied to cities:
Strong population growth, intensive industrialization and globalization make cities grow. Cities have been the world economic dynamos for centuries, attracting workers and productive business, benefiting from economies of scale. The migration and growth entails a remarkable impact on housing, resources, environmental issues, safety and security of existing systems.