With the population sky high, and the size of our cities reaching breaking point, the demand on the agriculture sector has never been higher. As our metropolitan areas start to sprawl out into the countryside the sustainability of traditional farming methods is seriously coming into question. But what kind of alternatives are being produced to satisfy our rapidly increasing demand for sustenance?

Empty warehouses, abandoned buildings and high rise estates aren’t exactly where you’d think of finding the first stages of an environmental revolution, but all across the world, from the warehouses of Chicago to the south pole growth chamber in Antarctica, the concept of high yield indoor farming is becoming more and more widespread. ‘Vertical farms’ are a new, environmentally friendly way to provide the huge amounts of fruit and veg demanded by cities across the globe.

So what actually is vertical farming? Plant scientist Dr Erik Murchie, from the University of Nottingham, reveals how agriculture could reach new heights (excuse the pun) in coming years. “It’s vertical because you are trying to grow more crops on a smaller land area and this usually means going upwards into buildings. It normally means that, instead of having a single layer of crops over a large land area, you have stacks of crops going upwards. It’s also associated with city farming and urban farming.”

Vertical farms aim to prevent a substantial amount of the issues that are inevitable when growing food crops in traditional fields. For example, the susceptibility of outdoor farms to drought and disease, and the fact that many of these crops are grown in fields which are hundreds of miles away from where the food will eventually be consumed. This has a critical effect on the environment.

Dickson Despommier, Columbia University ecologist, and founder of verticalfarm.com suggests that food should be grown throughout the year in ‘high-rise urban buildings’ in order to reduce the unsustainable carbon footprint that is currently necessary to transport all of our fruit and vegetables from producer to consumer. On his website Despommier claims:

‘By the year 2050, nearly 80% of the earth’s population will reside in urban centers. Applying the most conservative estimates to current demographic trends, the human population will increase by about 3 billion people during the interim. An estimated 109 hectares of new land (about 20% more land than is represented by the country of Brazil) will be needed to grow enough food to feed them, if traditional farming practices continue as they are practiced today.’

To Despommier, the key issue is that over 80% of the world’s suitable cropland is currently being used, and a further 15% has historically been laid to waste by ‘poor management practices’. You don’t have to be a maths genius to work out that this means we are using up crop space much faster than we can afford to.

To put this in perspective, in his interview with BigThink he states ‘the size of south America, in landmass, is used just to grow crops that we plant and harvest without even including the landmass used for farming herbivores, such as cows and sheep’, (a figure that is already staggeringly high and is causing a huge variety of problems in it’s own right) ‘the biggest problem facing us as a global species is: where will the food for the next three billion people come from?’

So the big question is: could vertical farming solve that problem?

Well yes and no. Despommier states: ‘There are many examples of vertical farms out there which are not traditionally thought of as ‘towering gardens of Eden’ … as the images on Google might suggest’. In fact the idea of the ‘farmscraper’ has led some commentators to be initially sceptical, mistakenly thinking that an urban farm which pierces up into the sky sounds more like something out of a sci-fi movie than a serious environmental solution (a bit more Soylent Green than Brighton Green!).

However the reality is much more simplistic. In March 2014, the worlds biggest vertical farm was opened in Scranton, Pennsylvania, but it wasn’t exactly the futuristic utopian ideal many of us will have been imagining. In fact, it is only a single story and it covers 3.25 hectares of land, but inside this vast building is a gigantic indoor farm filled with plants, each grown on a structure containing 6 vertical rows that, all in all, will house around 17 million plants.

The science behind it isn’t as sci-fi as you might imagine either. The plant racks in a vertical farm can be fed nutrients by water-conserving, soil-free hydroponic systems and lit by LEDs that mimic sunlight. And they don’t even need to be difficult to manage: ‘control software can choreograph rotating racks of plants so each gets the same amount of light, and direct water pumps to ensure nutrients are evenly distributed.’ It could also make food supplies more secure, because production can continue even in the midst of extreme weather conditions. And as long as farmers are careful to protect their indoor fields from pests, vertical farming doesn’t need to worry about using herbicides or insecticides.

One particularly important issue that vertical farms seek to address is that they conserve water far better than ‘earthbound farming.’ Green Spirit Farms was inspired by the long-term drought that has been a major problem across many of the driest regions in the USA. ‘Water is a big issue,’ says Daniel Kluko. ‘We have designed our vertical farms to recycle it, and they use 98 per cent less water per item of produce than traditional farming.’ The way this is done is, in part, by extracting as much water as possible from the grow room’s atmosphere with a dehumidifier. These dehumidifiers also serve a double purpose, they eliminate excess humidity that can lead to a variety of problems such as leaf mould among other things.

This re-utilisation of water has led to the idea of vertical farming being referred to as, what French philosophers Deleuze and Guattari in Thousand Plateaus call, an ‘apparatus of capture’. Indeed, a 2008 paper by Despommier and Ellingsen argued: ‘the vertical farm is an apparatus of capture, a filter which helps regulate the flow of urban energy in the form of water and waste management, redirecting those problematic outputs as energy inputs and agents of change for the production of our daily caloric needs.’ In other words, just as the farms themselves seek to redirect excess water that would otherwise be detrimental to the plants, on a large scale, the flow of water necessary to run a city can be better redirected to provide us with a source of nutrition directly from our own urban areas.

So, although vertical farming might not quite have reached the lofty heights of the ‘towering gardens of Eden’ that Despommier describes (yet), they are providing a realistic answer to a very pressing problem — from both a philosophical, and scientific perspective. Many farms now may only be ‘vertical’ in the sense that they exist in vertical rows inside rather horizontal looking buildings, but the future potentials of this increasingly viable technology have never been more promising. Is vertical farming the future? I think only time will tell. But who knows, maybe in years to come we will end up seeing towers of green populating the skyline of our cities!