IUESA: The immigrant population was estimated about 244 million people worldwide in 2015. 65.3 million of them immigrated because of conflict and homelessness. It has been predicted that 200 million people will become homeless by 2050.
Major part of immigrants, including 90 percent of them, settled in the cities of the U.S. Britain, Australia, and Canada in the past years. In this regard, these cities will face many problems such as health, lack of water resources, safety, and environmental hazards in coming years.
However, mass migration that we may consider today does not only contain problems. The studies indicate that cities can take advantage of this opportunity in order to have better economic condition and they should welcome this phenomenon instead of fighting against it.
However, the migration due to war, economic problems, homelessness, or other reasons warn cities to be prepared for facing their problems such as providing job or settlement. 
Moreover, cities should proceed to improve conditions and reduce shock caused by pressure on their natural ecosystems and prepare the ground for immigrants’ living conditions. They should be prepared for coming crises and take advantage of this opportunity to have a better community for their residents.
