Francois Mancebo weist auf der Seite „The nature of cities“ darauf hin, dass Landwirtschaft in der Stadt nicht automatisch gut ist. Mit der neuen Begeisterung für Gärten und Lebensmittelanbau in der Stadt, haben auch Ideen Aufwind bekommen, welche die Nachhaltigkeit der Stadt eher gefährden als fördern. Er hebt vor allem die Visionen von großen Indoorfarmen in Hochhäusern hervor. Diese würde die Städte mit Pestiziden verseuchen und mit ihren Hochhäusern das Stadtgefüge zerstören.
„Urban agriculture’s mania opened a window of opportunity to impose high-rise buildings or to turn intensive agriculture in the city “green”. All a sudden, concrete and glass towers became acceptable in places where not a single inhabitant would have accepted them before, provided that the buildings looked “green”. At the ground level, conventional urban farming became nice and acceptable, though it can generate nuisances such as dissemination of pesticides and fertilizers that have a negative impact on health and on the biodiversity in the city. Those who greenwash conventional or high-tech agriculture in the city as sustainable mislead. It is deeply problematic, as I will show with two very different cases that are connected in one important way: the exposure to pesticides of city-dwellers living alongside fields cultivated under intensive conventional agriculture, and the potential destruction of the urban fabric by skyscrapers camouflaged in green.“