Although current prospects for urban farming in cities like Paris do not seem to make it possible, let us imagine that a city develops the capacity to grow its entire food supply itself (be it by urban farming or by the developments of super foods like algae). It is therefore to think that all food related industries outside of cities will no longer be necessary and slowly be shut down. But what would happen in the case of a major issue in cities, like a natural disaster, or a power cut, that would therefore disturb the whole food production? This question is heavily influenced by the dystopian view of megacities by René Barjavel in Ravages. To what extent do we wish to put all our resources in the same city?