The World Urban Forum was established by the United Nations to examine one of the most pressing issues facing the world today: rapid urbanization and its impact on communities, cities, economies and policies. It is projected that in the next fifty years, two-thirds of humanity will be living in towns and cities. A major challenge is to minimize burgeoning poverty in cities, improve the urban poor's access to basic facilities such as shelter, clean water and sanitation and achieve environment-friendly, sustainable urban growth and development. The fourth session of the World Urban Forum takes place 3-7 November 2008, Nanjing, China