Image Credit: Dragonfly NYC Vincent Callebaut
The Hanging Gardens of Babylon. One of the seven wonders of the ancient world. Attributed to King Nebuchadnezzar II and described by writers of the time as a pensile paradise. Resembling large green mountains constructed of mud bricks; these gardens were the pride of the ancient Babylonians. Legend has it that the King created the gardens for his queen who missed the green hills and valleys of her homeland. Who would have thought that this gesture of affection would set the trend for modern agriculture today? Vertical farming, the act of growing food in high-rise buildings, could change the way we produce food in the future.
Feeding The Masses As The World Goes Urban
It is said that by the year 2050, nearly 80% of the Earth's population will reside in urban centres. Already Kenya's capital, Nairobi, is home to nearly 4 million people. With the devolution of government, facilitating more direct investment into counties, the growth of urban centres throughout the country is inevitable. While this is a sure sign of development, rapid urbanisation is likely to encroach on farmland and push food production farther away from town centres.
Limited access to ever-shrinking tracts of arable land coupled with a rising population will no doubt increase the cost associated with producing food and bringing it to the urban populace. It could even put to question the land's ability to produce sufficient food especially in the face of climate change. It is this global trend that has experts sounding the alarm and asking, "How are we going to feed all these people?"
Cultivating The Concrete Jungles
Concrete jungles, with tall buildings for trees and traffic for undergrowth, have grown out of a need to accommodate large numbers of people in comparatively small spaces. When you run out of space to expand horizontally the only solution is to build upward. But could this be true for agriculture as well?
According to the Food and Agriculture Organization of the United Nations (FAO), throughout the world, over 80% of the land that is suitable for raising crops is already in use. Growing crops in the heart of cities has been fielded as a possible solution to addressing a growing population's need for food and easing the pressure on the world's available arable lands. It has been suggested that a 30 storey, 27,800,000m2 vertical farm could feed 50,000 people, providing 2,000 calories for every person each day. But is it really possible to grow food in buildings?
A Thing Called Agritecture
The term agritecture is defined as buildings that grow food. The kind Kenneth Yeang, an architect, ecologist and author of Malaysian descent has been designing for years. Named by The Guardian as one of 50 people most likely to save the planet, Kenneth first developed the concept - and built prototypes - of mixed-use buildings in the late 80’s. The open-air buildings were climate responsive high-rises in which plant life could be cultivated alongside human dwellers. Kenneth's vision was to make urban farmers out of urban dwellers and so envisaged these vertical farms for personal and community use.
Dr. Dickson Despommier, award-winning professor of public health at Columbia University began looking into ways to commercialise this concept in the late 90s. In his book, "The Vertical Farm", which some consider the industry's bible, he promotes the mass cultivation of plant and animal life for commercial purposes in hermetically sealed skyscrapers.
So What Exactly Is A Vertical Farm?
"To put it simply, a multi-storied greenhouse" says Despommier. But vertical farms are far from simple.
They are buildings typically several stories tall where crops are stacked in enclosed spaces. Plants at most vertical farms are grown hydroponically, or without soil, in a sterile environment with precisely controlled climate. They are nourished through a recycled nutrient- rich water solution. Some such farms rely on aeroponics, where the water solution is misted onto the plants' roots and others still on aquaponics where waste from farmed fish is used as a fertilizer for the crops. There are sensors in place to detect even the slightest dip in nutrient levels.
Artificial lighting, more and more by LEDs than fluorescent bulbs, is required to mimic the sun's rays. The internal environment in these buildings must be carefully monitored at all times because even the slightest change in growing conditions could result in a failed crop.
Why Farm Vertically?
Proponents say vertical farms can surpass the productivity of existing agricultural spaces by up to 20 times, and while traditional farming allows for an average of 3 growing seasons, vertical farms would be productive throughout the year. This method of farming is also said to use 70% less water, and could virtually eliminate the need for pesticides and by extension GMOs thanks to a strictly controlled growing environment with sophisticated air filtration systems to keep out pests.
With vertical farming, food could be grown anywhere in the world regardless of climatic conditions due to the carefully artificially controlled environment. This method of farming is also said to be more environmentally friendly than traditional farming because it would significantly cut down the cost (both monetary and ecological) of transporting food over large distances as well as prevent the run-off of agricultural waste into rivers and other natural water bodies.
But these farms are more than just a response to the looming global challenges, they are also aligned with the demands of an increasingly aware global consumer who is not only keen to reduce his/her ecological footprint but also to gain access to healthier, locally grown foods. At the groceries section of Kenyan supermarkets, for instance, one can always overhear the question "is this local or imported?" with a clear preference for the former.
But Is It feasible?
10 years ago, vertical farms existed mostly as conceptual drawings with few actual prototypes. In recent years, however, interest has grown tremendously and now over 400 farms exist worldwide (at varying scales) in Japan, Korea, Singapore, the US, Canada and Sweden. Despite their increasing popularity, one major hurdle stands in the way of vertical farms taking root globally. The cost.
Image Credit: Comcrop Singapore Today Online
As one opposing view points out, "it takes a stock market to build a skyscraper", illustrating the fact that urban real estate is not cheap. The cost of setting up a high-rise building in Nairobi, Kenya’s capital is roughly KES 40,000 or USD 470 per m2. The aforementioned 30-storey building would therefore cost tens of billions of shillings, hardly a negligible financial investment.
In addition to the cost of construction there are very high energy costs associated with running the farms. The cost of artificial lighting, heating and other vertical farming operations would exceed the benefit of these farms’ close proximity to the areas of consumption. This would certainly be true in Kenya where the high cost of energy still remains a serious impediment to the growth of industries.
The Downside to Going Up
In addition to feasibility issues vertical farming brings with it an array of social and economic challenges.
Running on very sophisticated technology these farms remain largely inaccessible to developing nations. Even Kenya, despite being Africa's Silicon Savannah, is not yet equipped to take on this technology. With the bar set so high, this innovation remains the preserve of developed nations rendering one of its greatest selling points - increased global access to food - moot.
This farming method could also have a negative impact on rural communities. In Kenya, 80% of the food produced comes from rural small-scale farmers who depend on this income to sustain themselves. With the translocation of food production to cities, rural economies would take a major hit. Cutting off this source of income would not only exacerbate the divide between the rich and poor but would also see rural communities affected by various nutritional deficiencies as a result of being unable to practice even subsistence farming.
These farms could also spell doom for the world's arable lands and ecological sanctuaries which would soon be 'developed' given the available alternative of planting indoors.
While traditional farming relies heavily on favourable weather conditions for a good crop yield, vertical farms rely heavily on technology, which could fail putting the farm at stake.
If Despommier’s concepts are to be implemented fully, with animals also being vertically farmed, we could inadvertently cement the factory farming model, which has seen a sharp decline in popularity over the years.
An Opportunity In Disguise
Despite its pitfalls, Despommier argues that vertical farming presents an opportunity to innovate and explore alternative, more cost effective energy sources.
Besides the usual geothermal, wind and solar power, he cites human faeces as an underrated energy source stating "New York City defecates the equivalent to 900 million kilowatt hours in electricity every year, yet we spend billions of dollars trying to throw that stuff away when we could get energy from it by incineration".
He is not alone in recognising the opportunity. Already, large companies such as Philip's and Toshiba are developing state of the art, low cost LED lighting systems to respond to the growing need. Others still are developing what they call "smart farms" that can easily be installed in one's home and monitored remotely through a mobile device.
Still A Ways To Go
Vertical farming is still very much in its infancy. But all the efforts going into making the technology more affordable combined with further innovations in agritecture could see it become a feasible food production method even in the Silicon Savannah.