This means within 3 decades, cities will grow 2 billion people, in average 323 million every year. The world should provide new housing and services for 800 thousand people every day.   

This high demand of resources combined with the migration factors put a lot pressure over the cities and the communities. Facing difficulties for coverage and access to public services, generating pollution, congestion, and poor housing quality due the fast-urban sprawl. Some countries are expecting to double their size in sub-Saharan Africa 99%, in Latin America is expecting 18% population growth, while Northern Africa and Western Asia are 46% growth, by 2050. Consequently, their cities are challenged by the fast-urban growth in the next few years.