History tends to show that urbanization has always been accompanied by a movement of agriculture towards monocultures and peasant exploitation. When a city became established and grew into an initially rural area with self-sustaining polyculture farms, in order to survive, it had to put in place a whole process of food supply from the surrounding countryside. The peasants had to produce much more, and in such a way that the harvest was faster.
The polyculture practiced on a self-sufficient family farm, on a surface of the order of a few hectares (between two hundred and five hundred square feet), allowed to feed some families of medium size or a large family. It was possible even without the practices currently used in permaculture (which allow better harvests without digging over the soil). Such farms scattered over a region were generally sufficient to feed the corresponding rural community, even in the event of crop failures in some parts of the area, as there might be some surplus on other farms. However, when a city appears in such a neighborhood, its inhabitants are not agricultural producers and therefore depend on the surrounding peasants.
The more a city grows, the more it parasitizes the surrounding agricultural environment. A large urban population is, of course, more involved with the surrounding peasants, demanding increased production in proportion to the growth of the city. However, polyculture practices are no longer adapted to such a need. As agricultural resources are not sufficient, the nascent urban civilization tends to impose a new agricultural approach to perpetuate (see the Note on the Collapse of Civilizations). It calls for a method of collecting and distributing production more efficiently. Thus, more often than not, we see farms appear more and more turned towards monoculture on wide surfaces.
The problem of monoculture (especially with mechanical means, by digging over the soil, and using chemical fertilizers and pesticides) is the ease with which it destroys the soil, and impoverishes the peasants to end up enslaving them for the benefit of the townspeople. At the same time, because it concentrates a large population on a small area, the city is an important factor of environmental pollution, because it does not have enough space to benefit from the regenerative capacities of the planet. And the case is aggravated when the inhabitants of the city become overconsumer and wasteful. Then, it evacuates its industrial quantities of waste in the neighborhoods, without these being able to be quickly assimilated by the ground.
Finally, a city behaves like a cancerous tumor. It feeds on the health of its host (the agricultural region) and tends to grow again and again, to the point of becoming today huge megacities of several million people. And of course, these are all the more polluted and generating environmental degradation. Cities kill slowly, and sometimes more rapidly, peasants, animals, trees, and planetary life in general. These are real cancers for the planet. On the contrary, the New World will see the gradual disappearance of cities, an essential condition for a return to global health.