Such is the thinking behind vertical farming. The idea is that skyscrapers filled with floor upon floor of orchards and fields, producing crops all year round, will sprout in cities across the world. As well as creating more farmable land out of thin air, this would slash the transport costs and carbon-dioxide emissions associated with moving food over long distances. It would also reduce the spoilage that inevitably occurs along the way, says Dickson Despommier, a professor of public and environmental health at Columbia University in New York who is widely regarded as the progenitor of vertical farming, and whose recently published book, “The Vertical Farm”, is a manifesto for the idea. According to the UN's Population Division, by 2050 around 70% of the world's population will be living in urban areas. So it just makes sense, he says, to move farms closer to where everyone will be living.
Better still, says Dr Despommier, the use of pesticides, herbicides and fungicides can be kept to a bare minimum by growing plants indoors in a controlled environment. Soil erosion will not be a problem because the food will be grown hydroponically—in other words, in a solution of minerals dissolved in water. Clever recycling techniques will ensure that only a fraction of the amount of water and nutrients will be needed compared with conventional farming, and there will no problem with agricultural run-off.