Each day the world population increases by over 200,000, demanding more shelter, bread and new city for more than a million inhabitants every week. According to UN News Centre on 24 February 2005, almost all of the increased population is taking place in the less developed countries, whose populations is expected to reach 7.8 billion in 2050 from 5.3 billion now, while the population of the developed countries will remain around 1.2 billion, it says. Between 2005 and 2050, eight countries like India, Pakistan, Nigeria, the Democratic Republic of Congo (DRC), Bangladesh, Uganda, the United States, Ethiopia and China are likely to contribute half of the world's population increase, while the population would at least triple in Afghanistan, Burkina Faso, Burundi, Chad, Congo, the DRC, Timor-Leste, Guinea-Bissau, Liberia, Mali, Niger and Uganda (Dutta and Mandal, 2018)

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