Our home in space

some remarks on global heating and ocean acidity

Guy Ottewell

Vertical farming

To grow their food, humans have now taken over a huge fraction of the planet's land surface: around 7 million square miles, the size of South America. There will be about 2,500,000,000 more people by 2050, so more land, the size of Brazil, will be needed to feed them, but that amount of farmable land does not exist.
     Instead, food can be grown on a vastly smaller area, within cities: in greenhouses or on rooftops or in buildings that can be several or many levels high. These vertical farms can make use of the many waste lots that now exist within cities. They can be close to the densest and poorest communities that need them most. Distribution can be at the door, instead of by long haul from distant farms. Plants can be grown hydroponically (in water), round the clock and round the calendar. Food would be much cheaper. There would be huge savings of the fossil fuels now used for farming machinery and for transportation, of water, of fertilizers, of pesticides, of erosion of topsoil and runoff of silt. Such farming would not be at the mercy of extreme weather and of the shifting of climatic zones. And, perhaps the most attractive feature, much of the countryside now taken up by vast areas of monoculture can revert to nature — to the landscape as it used to be.
     The drop in use of fossil fuels, and, even more, the restoration of the natural carbon cycles of the plant world, could be enough to halt the rise in carbon dioxide emission.
     Vertical farming is already being tried. See this better description.