The world population increased rapidly, especially in the second half of the twentieth century. In the later years the population increased by 1 billion, the more shortened. Currently, the world population increases by nearly 80 million people annually. The population is expected to be stable by 2025 with a population of about 8 billion.
 The current world population boom takes place mainly in developing countries. These countries account for about 80% of the population and 95% of the world's growing population. The rapid increase in population in the world is reflected in several main causes such as Population and migration habits, nomadic; urbanization; cities with more than 1 million people. To date, the world has over 270 cities per million people and 50 cities over 5 million people. Great pressure on natural resources and the earth's environment due to overexploitation of resources for housing needs, food production, food, industrial production,...