BY Jack Klein
By 2050, production of 60% more food than we produce today will be required to support Earth's population, which is going to be an estimated 9.7 billion people. The traditional method of farming (that of harvesting crops in extensive outdoor plots of land) is a main contributor of greenhouse gas emissions, water use, and water quality degradation from nutrient runoff and soil loss. After 2030, climate change’s most important impact will come from the increased frequency and intensity of extreme weather events such as droughts and floods, causing serious negative effects on traditional agriculture.
If by 2050 we have to greatly increase global food production to meet the basic needs of our growing population but the traditional method of food production has proven to be detrimental to our environment, accelerating climate change which in return is expected to gravely affect its resiliency, one question arises: are there any methods of food production that can protect from the increasingly vagarious environment, help meet future global food production goals, all while having a neutral or positive impact on the environment?
One possible solution is the relatively new idea of vertical farming, or building farms up in climate-controlled buildings rather than out on environmentally susceptible land.
Due to the complexity of the global food security issue, I want to concisely explain the practice of vertical farming and its theoretical advantages over traditional farming, but then analyze its viability as a true potential solution to our food crisis.
Vertical farming (VF) is an intensive farming practice that involves large-scale production of crops in multi-story buildings, often in urban areas, mainly employing advanced techniques such as hydroponics and aeroponics. Advantages of VF over traditional farming include the multiplication of agriculturally productive land, an increase in crop yields, the heightened resiliency of crops, and the minimization of water usage. VF multiplies agriculturally productive land because it is an intensive farming practice and optimizes the use of vertical space; one indoor acre is equal to 4-6 outdoor acres or more. VF is able to increase crop yields due to its controlled indoor environment, which can control temperature and CO2 levels, filter the air, and recycle excess nutrients released into the air, allowing for year-round production. Also, via artificial lighting, each crop can be exposed to its required wavelength of light for the optimal amount of time.
The controlled indoor environment furthermore protects the crops from weather-related problems, pests, and diseases. These problems are all beyond the control of traditional farmers, and lead to the use of costly pesticides and fertilizers that in turn can pollute water sources through runoff initiated by heavy rainfall.
Finally, using aeroponic techniques that involve spraying nutrient rich mist directly onto the plants’ roots rather than using soil, VFs can reduce water usage by 90%, fertilizer usage by 60%, and increase crop yields by 45 to 75%. And with a water recycling system, the water that is not absorbed by the roots is captured, re-circulated, and sprayed again- VFs are in complete control of the closed-loop water irrigation system. Considering irrigation for traditional farming accounts for ~90% of global water consumption, this characteristic of VF when paired with aeroponics truly shines.
These advantages of VF, in theory, make it sound like an obvious choice for the future path of global food production. However, the political and socio-economic factors that affect the market potential of vertical farming are absolutely vital to understanding the practicality and viability of VFs in helping to solve global food crises. Realizing this, researchers Chirantan Banerjee and Lucie Adenaeuer designed and simulated a VF and performed a market analysis to truly understand the strengths, weaknesses, external opportunities, and threats that must be considered when moving forward with vertical farms. Through this analysis, the viability of VF as a realistic option to our growing food problem was dissected and more understood.
Banerjee and Adenaeuer's simulated VF was sited in Berlin, is 37 floors, and provides around 15,000 people with 2,000 kcal of nutrition a day. It focuses on growing eleven types of crops, including potatoes, strawberries, lettuce, and tomatoes. The fixed costs, mainly building and equipment costs, total to just over 200 million Euros. The variable costs, including power supply and plant nutrients, cost an estimated eight million Euros per year. Power supply alone costs over five million Euros per year, and therefore energy cost is a big concern and draws much skepticism from business and academia. However, VFs use less fossil fuel energy due to the lack of agricultural machinery.
The major weakness of VF is that the space, light, CO2, and water all required by crops cost money in the regulated environment. Because the required LED lighting is the main contributor to the skewed energy usage, if future VF projects can integrate renewable power sources this will not only increase marketability but also help mutually subsidize their costs. For instance, VF could be seen as a highly attractive practice in regions that seek food sovereignty, but whose agro-climatic factors are too aggressive for traditional agriculture.
Vertical farming receives a heavy dose of skepticism, because no project has actually built and shown the viability of a VF as robust as those simulated in academic articles. However, this is not to say large-scale VF projects have not been built. The largest VF in Japan, Spread factory, harvests 21,000 heads of lettuce of day, totaling to 7.7 million heads a year.
Producing only leafy greens is not unique to Spread, and is the common trend among VF startups. Leafy greens have a short growing season (30-40 days), less variance in taste thus easier to gain market acceptance, and they are in demand year-round. Due to industrial-sized VFs’ current focus on easier, less nutritious crops, understandable given the start-up expenses, the steep costs involved in building VF infrastructure and technology, and the amount of energy required to provide artificial sunlight, it is currently only an expensive niche that can help supplement the food provided by traditional farms rather than a method communities all over the world can utilize to gain food sovereignty and respond to incompatible agro-climatic factors and growing cities.
VF truly offers some exciting solutions to global food production and advantages over traditional farming. While much more research of the technologies and renewable energy options are needed to reduce the costs of the initial startup and large energy use, VF startups are attempting to reform the way humanity does agriculture. Even if VF is not the long-term solution to meeting the food needs of our growing global population, the research involved, along with the initial physical implementations, are invaluable for starting important conversations and innovating for the future.
Students in Jess' ENV 151 Introduction to Sustainability write blog posts on a sustainability-related topic of their choice.