In the average age, had to the practised commerce the long distance, the cities had acquired the feio of commercial warehouse. In century XIX, the Industrial Revolution brought a new concept: the quality of life already threatened by the pollution generated for plants in the Europe. At the beginning of century XIX, London was the only city that reached the population of a million of inhabitants. In 2005, 15 megacidades had been entered, that is, groupings with more than 10 million inhabitants, and in 2025, according to data of the ONU, will be 22 in the whole world. The modern city becomes a concentrative polar region of commerce, services and information.
It starts to be the main space of consumption and circulation of wealth produced in the field. Many believe that the developing countries can reproduce the transistion of the predominantly agrarian agricultural economies for industrial urban economies following the trajectory of what Occidental person occurred in the Europe. Millions of European peasants had crossed the Atlantic since middle of century XIX in direction to Americas. With the increasing mechanization of the farming one becomes necessary to rethink forms of setting of the man in the field. The peasants are qualified to make essential ambient services, to watch over for the landscapes and natural resources as ground, waters, forests and climate. To remunerate these services of form joust will go to decelerate the agricultural exodus and to prevent swell of already degraded urban areas of great centers.
Not yet a city exists that can be considered total sustainable. But one imagines that, up to 2020, several will be able to come to be. It starts to be born the concept of ecocity? a thought city to be entirely sustainable, as Dongtan, in China. The first phase of the project, ready in 2010, will contemplate 10 a thousand inhabitants. Up to 2050, 500 a thousand inhabitants must change themselves for there.