The Future of Food
How are we going to feed 2 billion more people in 30 years time? Vertical farming may be part of the answer.
The idea of vertical farming is one which is relatively new, first proposed in 1999 by Dickson Despommier, a professor of Public and Environmental Health at Columbia University. Despommier and his students popularised the concept of vertical farming by constructing a design of a skyscraper farm that had the capacity to feed 50,000 people; the design has of yet not been built (Cooper, Pacific Standard, 2017). The concept of vertical farming is of growing crops stacked on top of each other and incorporates controlled-environment agriculture, as well as soilless farming techniques such as hydroponics, aquaponics, and aeroponics. The recent discussion surrounding vertical farming proves to be one of the utmost importance, considering the UN projections of a 2 billion population increase by 2050 (United Nations, 2019). While we are currently experiencing a climate crisis which according to researchers from the OECD agriculture contributes a large share of, with a greenhouse gas emissions totalling to around 24% via the entire agriculture sector (OECD, 2016).
The current projections of population increases mean agricultural practises must be enhanced and intensified in order to meet the incoming demands of an estimated 2 billion people. All the while, our climate is struggling to cope with the current agricultural practices and a further expansion of our current agricultural mechanisms — through high levels of water use, large scale land use, deforestation, etcetera— will only exacerbate the climate crisis, leaving large parts of the planet uninhabitable for billions of people. So, could vertical farming be the solution we are looking for?
Less Water Usage
Water usage in the past decades has increased so much that this once deemed infinite resource is currently becoming scarce within many regions of the globe. Take for example in South Africa, Cape Town, where water supplies became so low that the municipal government discussed a possible Day Zero — where the cities water supply would be shut off entirely — luckily, however, they averted this catastrophe with massive scale water-saving initiatives. In the most extreme cases in Cape Town water was reduced to only 50 litres a day — incredibly difficult considering showers alone can use 15 litres a minute (Edmond, World Economic Forum, 2019).
The problem of water scarcity is not restricted to South Africa, as a whole two-thirds of the world population will be water-stressed — meaning “when the demand for water exceeds the available amount during a certain period or when poor quality restricts its use.” (EEA,2020) — by 2025 if current consumption trends continue (World Economic Forum, 2019). These worrying figures become even more so when we realise the amount of fresh water used by the agricultural sector, accounting for around 70% of all water withdrawals, making it a major cause and casualty of water scarcity (World Economic Forum, 2019). The problems of which will only be exacerbated by climate change, worsening the entire problem of water scarcity, with the warming of the earth and increased droughts.
But vertical farming proves to have an answer to the massive amounts of water the present agricultural sector uses, helping to revive our old and decrescent agricultural practices. Firstly, vertical farming uses water far more efficiently, for instance, studies have shown that open field production (the traditional farming method) uses 250 litres of water per kg of lettuce, while vertical farming uses only 1 litre per kg of lettuce (Eit Food, 2018).
The amount of water that can be saved is revolutionary for the farming industry, with Tower Farms (a vertical farming company) claiming to use 95% less water than traditional farming methods, but with higher crop yield (Tower Farms, 2020). The ability to produce more food, while using less water, significantly reducing the 70% of freshwater consumption by the agricultural sector implies that vertical farming is the way of the future if we want to provide billions of more people with food in a more sustainable way.
Going Upwards
Instead of having miles upon miles of land dedicated to farming, using far to much water and causing the gradual reduction of arable land, switching to vertical farming seems like a no brainer. Our traditional methods of farming have seen the amount of land used by the agricultural sector increase drastically. One study has shown that half of the world’s habitable land is used for agriculture and will use even more in the future to meet the demands of a rapidly growing population (Ritchie, Our World In Data, 2019). Statistics from the United Nations Food and Agriculture Organisation (FAO) expand upon this, revealing the incoming global problem that is occurring. The decreasing stock of agricultural land per capita will by 2050 see arable land per person decrease to one-third of the amount that was available in 1970 (Benke, et al, Future food-production systems: vertical farming and controlled-environment agriculture, 2017).
So, how will we be able to counteract this imminent threat and reduce the amount of land used for farming as well as provide enough food to sustain a growing population? Once again, vertical farming appears to have the answer.
Vertical farming will utilize a smaller space far more efficiently than that of a traditional farm which is spaced out horizontally, while also being able to provide a far wider variety of food products, and the crop output per acre of land will be maximised (Kalantari, et al, Opportunities and Challenges in Sustainability of Vertical Farming: A Review, 2017). The prospect of a growing population which according to the UN will see as many as 68% of the world population living within urban areas by 2050 (the total is at almost 90% in Asia and Africa); making space an even more vital commodity in urban centres than it is today, provides a promising opportunity for vertical farming (United Nations, 2018).
A study by Victor Mendez Perez of Purdue University also reiterates the magnitude of space that will be saved by vertical farming. Perez, who focused his study around lettuce production found that if outdoor farming went indoors there would be a 20-time reduction in land use, as well as an improvement in land usage and savings of 95%. The case, however, is different according to which crops are being produced. Nonetheless, the prospect of vertical farming will help limit the surface land use for food production in cities effectively, allowing the former farmland to return back to its natural state and replenish the soil (Perez, Purdue University, 2014). The potential of land being used more effectively seeing the cultivation of larger food quantities within a smaller space will be vital within the incoming years, so vertical farming proves to be important, in some instances vital, step to consider.
Higher Crop Yields
The factors that are increasingly making traditional farming ineffective, be it due to the massive amounts of water used or the large percentage it contributes to climate change has left traditional farmings effectiveness being questioned, leaving many to believe it’s days are numbered. Vertical farming will modernise agriculture enabling farmers to produce higher crop yields within a smaller space.
One study found that if you were to grow lettuce on a traditional open field of 1x1 meter, the yield would be 3.9kg every year. Compare this to the hydroponic greenhouse (a soilless vertical farming technique) where lettuce is grown on the same acreage it will provide you with a harvest of 41kg. A significantly higher yield and the ability to take up less space in the process, due to the controlled environment of the greenhouse allowing for continuous production year-round (Barbossa, et al, Comparison of Land, Water, and Energy Requirements of Lettuce Grown Using Hydroponic vs. Conventional Agricultural Methods, 2015). The ability of vertical farms to produce a higher yield is continuously proven in studies, another such study conducted by the University of Dundee found that vertical farming can yield 20 times more than that of traditional agricultural fields (Frediani, University of Dundee, 2011).
Reduction In Green House Gas Emissions
Carbon Dioxide levels are higher today than they have been at any point in at least the past 800,000 years (Lindsey, Climate.gov, 2020). And we are all more than aware of the severity of the climate crisis, with the UN warning we need to halve global emissions by 2030 to avoid catastrophe (Watts, The Guardian, 2018). Agriculture as a sector within the EU-28, according to the European Union, contributed 10% of total greenhouse emissions in the EU in 2012 (European Union, 2020). World wide agricultural production accounts for 11% of total greenhouse gas emissions, rising 14% since 2000 but will continue to rise with an ever-growing population, therefore causing agriculture to contribute an even larger percentage (Arcipowska, et al, World Resources Institute, 2019).
The prospect of vertical farming and the different techniques it uses can be utilised and significantly reduce the greenhouse emissions which are warming our climate. For instance, one report by a Dutch organisation OneFarm found that vertical farming has the opportunity to reduce CO2 outputs by 70%, helping alleviate the agriculture sectors large contribution to greenhouse gas emissions (OneFarm, 2011).
The transportation of goods, many of which are agricultural, also is a major contributor to greenhouse gas emissions. Farms are often located on large open plains with fertile soil, and far away from metropolitan areas. This has caused farmed goods to travel thousands of miles to reach their markets, leaving the transportation sector accounting for 28% of greenhouse gas emissions within the US in 2018, according to the United States Environmental Protection Agency (EPA, 2020). Vertical farming will be able to settle anywhere, regardless of climate and soil conditions. Thus allowing farms to be located closer to customers, potentially even within a metropolitan area significantly reducing the amount of ‘food miles’ travelled, positively effecting travel costs and reducing greenhouse gas emissions (Eit Food, 2018).
Vertical Farming Is Not Perfect
Like anything, vertical farming has its flaws which would need to be addressed before this promising prospect replaced our current agricultural system. One of the main drawbacks of it being implemented widely is the large amounts of energy needed to grow the crops: coming in around 30–176 kWh per kg more than greenhouses (Eit Food, 2018). The price of this proves to be ghastly as the journalist and environmental writer George Monbiot revealed, calculating the amount of supplementary light needed to grow enough grain to make a single loaf of bread would cost around $15 (Monbiot, 2010). Further researchers have shown that if solar panels were used for the energy consumption of a vertical farm, you would need an area 20 times that of the multi-storey vertical farm, an extremely difficult feat to achieve (Benke, Future food-production systems: vertical farming and controlled-environment, 2017).
Another problem encountered by vertical farming is the cost, as you'd imagine the vast amount of energy needed compared to a traditional farm as well as the start-up costs has left vertical farming a pricey option. The idea of vertical farms being located within urban areas is good, but the office occupancy costs are high in many major cities around the world. Take for example office spaces in cities such as Moscow, Tokoyo, Dubai, Milan, and Zurich the prices range from $1850 to $880 per square meter (Economist, Pocket World in Figures, 2020). Since the concept of vertical farming aims to be centred within major cities they would incur occupancy costs, the same as other office spaces would within the same zone, which in many cities are incredibly expensive. Using Victoria, Australia as an example, a hypothetical vertical farm with ten levels would cost around US$349 per square meter of arable land, compared to a traditional farm in rural Victoria with a cost US$0.40 per square meter of arable land (Benke, Future food-production systems: vertical farming and controlled-environment, 2017).
Alongside the massive amounts of energy needed to produce farmed goods and the sheer expense of it all, climate change can also be negatively affected by vertical farming. If the power needs are met by the burning of fossil fuel, the gains made by vertical farming over traditional farming in the fight against climate change will be made redundant. But, with cities heading towards more renewable energy sources vertical farms could reduce their carbon footprint by producing or even purchasing their own clean energy (Eit Food, 2018).
The prospect of vertical farming is an exciting one, however, there are many areas which need tweaking to enable it to truly revolutionise the way we produce food. Nonetheless, vertical farming is something which is plausible within our lifetimes and will be vital to feeding 2 billion more people by 2050.
