As the population grows and urban sprawl means that cities develop into the outer areas, it could be possible that much of the land could become large urban city areas. However, many landscapes of the world are not fit for human inhabitance, for example, snow landscapes, mountains, deserts, and jungle are potentially harsh terrains for human survival. To prevent land also from being occupied as one city, government legislation and laws are in place allowing for a percentage of land to be untouched. The Earth needs green spaces and open spaces for air quality control and also for agricultural purposes. The likelihood is that cities will grow out a little bit, but more likely to grow upward and then potentially into space.