Intensifying indoor urban farming through the establishment of vertical farms (or high-rise farms) in urban centers is the likely solution to the swelling human population. The argument in favor of vertical farming in relation to food security is convincing, plus it has plenty more benefits too.
According to the United Nations Population Division (2009), the world population will increase from about 6.9 billion in 2010 to 9.2 billion in 2050 or an addition of about 2.3 billion more people to feed. The percentage of urban population will likewise increase from 50.46% in 2010 to 68.70% in 2050. It is expected that world population will continue to increase. Currently, the rate of growth per year is about 80 million.
This is a major concern because the land area of the Earth is limited only to about 13 billion hectares. In 2008, the total agricultural area in the world was about 4.88 billion hectares (FAOSTAT, 2010).
In consideration of the world forecast on population growth rate, food security, adverse effects of the continuing horizontal farming activities on the ecology and climate, health and nutrition and other factors, the advantages of this farming technology are summarized:
1. Increased and Year-round Crop Production. This farming technology can ensure crop production all year-round in non-tropical regions. 1 indoor acre is equivalent to 4-6 outdoor acres or more, depending on the crop. For strawberries, 1 indoor acre may produce yield equivalent to 30 acres.
Despommier suggests that a building 30 storeys high with a basal area of 5 acres (2.02 ha) has the potential of producing crop yield equivalent to 2,400 acres (971.2 ha) of traditional horizontal farming. Expressed in ratio, this means that 1 high-rise farm is equal to 480 traditional horizontal farms.
Furthermore, indoor farming will minimize infestation and post harvest spoilage.
2. Protection from Weather-related Problems. Because the crops will be grown under controlled environment, they will be safe from extreme weather occurences such as droughts and floods.
3. Organic Crops Production. The advantages of this urban farming technology can be further exploited by large scale production of organic crops. The controlled growing conditions will allow a reduction or total abandonment of the use of chemical pesticides.
4. Water Conservation and Recycling. According to Despommier, the vertical farming technology includes hydroponics which uses 70 percent lesser water than normal agriculture. Aeroponics will also be used which consumes 70 percent less water compared to hydroponics. Urban wastes like black water will be composted, recycled and used for farming inside the building. Sewage sludge will be converted to topsoil and processed for the extraction of water for agricultural use or drinking water.
5. Environment Friendly. Every land area that will be developed for this farming technology will reduce by a hundred fold the necessity of utilizing land for food production. These farms could be reverted to their natural state. This will promote the regrowth of trees which are effective in CO2 sequestration.
Growing crops indoor reduces or eliminates the use of mechanical plows, and other equipment, thus reducing the burning of fossil fuel. As a result, there will be a significant reduction in air pollution and CO2 emission that cause climatic change. Furthermore, CO2 emission will be reduced from shipping crops across continents and oceans. A healthier environment will be enhanced for both humans and animals.
Lesser disturbance to the land surface will also favor the increase in the population of animals that live in and around farmlands. Vertical farming therefore favors biodiversity.
6. Human Health Friendly. Indoor farms will reduce the occupational hazards associated with traditional, horizontal farming. Such risks include: accidents in handling farming equipment, exposure to infectious diseases like malaria, exposure to poisonous chemicals, and confrontations with poisonous or dangerous animals.
The availability of fresh and safe food will be beneficial to the population.
7. Energy Conservation and Production. Selling of the crops in the same building in which they are grown will significantly reduce the consumption of fuel that is used in transporting the crops to the consumers.
Vertical farms can also generate power. Although a 30-story vertical farm needs 26 million kwh of electricity, it is capable of generating 56 million kwh through the use of biogas digesters and by capturing solar energy (medicalecology.org).
8. Sustainable Urban Growth. Vertical farming, applied in a holistic approach in conjunction with other technologies, can allow urban areas to absorb the expected influx of more population and yet still remain food sufficient. The technology could provide more employment to the rural populace expected to converge to the cities in the years to come. However, traditional farming will continue because many crops are not suited to indoor farming.