Imagine being in a city restaurant and ordering fresh organic Spring greens, knowing they are supplied, not from a farm 100 miles away but from the tower block next door. This is the vision of Dr Dickson Despommier, the public health professor at Columbia University, who has been exploring the concept of vertical farming for almost a decade.

‘By 2025, the world’s population will swell to eight billion,’ explains Professor Despommier. ‘We will need additional farmland, roughly the size of Brazil, in order to sustain us all but that amount of arable land is simply not available. We are already outpacing the ability of outdoor farms to grow enough food, so an alternative strategy is required.’

Professor Despommier believes that growing our food in climate-controlled skyscrapers, each designed as fully self-sufficient ecosystems, could be practiced large-scale in all inner city developments. Potentially they could supply enough to comfortably feed all of humankind for the foreseeable future ñ sustainably too. They might even reduce the likelihood of future armed conflict over dwindling resources, such as water.

Farming in this way would also allow large tracts of land to revert back to its natural state, put an end to any further forest clearance and so help restore the planet’s ecosystems. We would, in effect, for the first time since our transformation from primitive hunter gatherers to sophisticated urban dwellers, be able to leave the world alone and let it grow’.

‘Here’s a way to replant the trees that were taken away to make room for the farms,’ Professor Despommier says. ‘If we put all the trees back, we can suck up carbon dioxide from the atmosphere and we can have food. It seems to be solving two major problems at the same time.’

Cultivating our food in farmscrapers’ would also protect it against weather-related hazards, ensuring a better quality supply, without the use of pesticides or chemicals. Furthermore, the organic part of human and agricultural waste could be re-used to produce energy through the generation of methane gas. Sewage could be pressurized to separate it into water and carbon, which would then fuel incinerators to power lights or machinery. ‘With waste in and food out, a vertical farm would be like a perpetual-motion machine that feeds lots of people,’ says Professor Despommier.

The idea of bringing food closer to the city is gaining interest with city planners. A small-scale design of a vertical farm for Seattle won a regional green building contest in 2007. A Centre for Urban Agriculture, it would supply a third of the food needed for those who live there.

Gordon Graff’s Sky Farm, proposed for Toronto, is a 58-floor tower block that would produce as much food as a thousand-acre outdoor farm. While the lower levels could house chickens for eggs and meat, 750,000 square metres of high-rise hydroponic paddy fields could grow salad greens to soya beans.

Delta Park, which sadly folded due to public concern that it appeared too over-industrialised, was to be built in Holland. It would have been the world’s first self-sustaining urban farm complex ñ a six storey agricultural machine in the Port of Rotterdam. Similarly, it featured wind turbines, recycling systems, greenhouses full of vegetables up top, fish breeding in the basement, while mushrooms and chicory could flourish below the ground, where no daylight penetrates.

For now, vertical farms still remain a virtual concept but scientists insist that the theory is sound. All we need, they say, are the adequate funds to make them a reality. Professor Despommier believes their time has already arrived ñ places where good health, employment opportunities, clean air, an abundant supply of farm-fresh food and safe drinking water could all be part of the package.

‘To insure their success,’ he says, ‘we need to construct them in so desirable a way that every neighbourhood will want one. Even if it’s not completely natural or even if it’s a bit factory-like in terms of production, here’s what you’re going to get back: you’ll get back the rest of the Earth ñ and I’ll take that any time.’

Contact: Dr Dickson Despommier,
Environmental Health Science,
Columbia University, 60 Haven Avenue,
Room 100, New York 10032, USA
Website: www.verticalfarm.com

Photo: © Dr Dickson Despommier