We have just looked at the emergence of a system of food production that no longer requires the use of land, light, and sun, and creates its own environment, all perfectly suited to urban life. In this chapter, we will examine transformations in food products that point to radical changes in the human diet through the supply of equally nutritious and tasty substitutes for the whole range of animal protein products: meats from all kinds of animals, milk and dairy products (butter, cheeses, whipped cream, yoghurts, ice cream, and even human milk), eggs and egg products (mayonnaise, egg white), together with fish and shellfish of all kinds.

It is not only a question of increasing the number of vegetarian and vegan options, millenary traditions in human history and strongly represented in the founders of the modern food industry, as indicated in previous chapters. Nor are the motives limited to spiritual or mental and physical health issues but include the valuing of animal welfare in the face of the cruelty of industrial systems of rearing and slaughter. Added to this is the perceived impossibility of generalizing an animal protein diet to the increasingly urban global population, given the example of the extraordinary growth of Chinese demand for meat in the last two decades. Above all, however, are the costs of the various animal protein chains, in terms of fossil fuel use, destruction of forests and biodiversity, and their strong contribution to greenhouse gases.

This set of factors is driving the extraordinary wave of product innovations whose stated aim is to replace the conventional global animal protein food chains. Climate-controlled agriculture and vertical farming promise to displace much of ‘protected’ agriculture and integrate horticulture into urban life. Alternative proteins based on plants, algae, fungi, and insects promise a drastic reduction of land devoted to livestock and feed production. Half of the world's habitable land is devoted to agriculture and 70–80 per cent of this to livestock (Ritchie and Roser, 2024 ). The release of this land for rewilding of various kinds, especially in the form of reforestation, extends beyond the recovery of cattle-raising areas, because the direct consumption of vegetable protein also avoids the costs of converting this protein into animal protein, which in the case of beef demands eight to ten kilograms of feed for one kilogram of meat.