The following is an over-simplification of the problems facing developing food production technology and delivery but there is a matter to be shared in this topic and that is in closed-loop nutrition, i.e. using urban wastes to provide the fertiliser to feed the people who produce the waste. Wastes contain a wider range, and larger amounts of trace elements than mineral fertilisers and, in effect, are Carbon neutral in production. (Bear in mind that UN-sponsored research showed that the electrical energy to make 1 tonne of Nitrogen nutrient in a modern USA factory is 21,000 kWh!) The human race has to take the urban waste route to nutrition if it is to survive. See the evidence and practical record of how it has been done safely in “Survival” by Bill Butterworth, Amazon and Kindle.