Megavatías; the increasingly urban world

In the last hundred years human beings have been able to live in the cities. In the last forty years, the world population has doubled, while the number of urban inhabitants has multiplied by five. We are seven million people in the world and more than half live in cities. In addition, one in ten of the population lives in only 21 cities. These 21 are two megacities, with a population greater than ten million. In addition to the number of inhabitants, the resources of the people of the cities have a great influence on the development of the cities. Thus, cities evolve in one way or another. As living beings.