The human world population has dramatically increased in the past century, from 1.6 billion in 1900 to 7.3 billion in 2015. It is estimated that the world population will peak at 10 billion within this century, around the year 2050. As the population increases, limited resources will become more and more scarce, such as food and fresh water. Currently there is already a lot of people who are undernourished. This problem will only increase as the population increases.
Experts have estimated that earth has enough farmable land to support a maximum of 10 billion people, assuming that majority of the human population changes their life style, such as converting to vegetarians as livestock requires a lot more farmland to raise. This doesn’t even account for climate change, which decreases the yield of grain crops by 10% per degree Celsius over 30. Also, research on soil degradation has shown that today, almost a quarter of the world’s farmland is affected by serious degradation. Approximately 30% of the world’s cropland has become unproductive over the past 40 years, and a lot of the regions with stable soil are unsuitable for farming due to weather and other conditions and variables.
If nothing changes, our current life styles will be unsustainable in the future, as population increases, farmland decreases and degrades, and climate change increases the global temperature.
One possible solution, or at least a strategy to alleviate some of the problem, would be the creation of vertical farms. Vertical farms can refer to two different types of farms. Farms that are grown on rooftops of buildings such as skyscrapers in cities, or industrial indoor farms, in which plants are grown in vertically stacking farms. This blog post will concentrate on the later type of vertical farms.
Vertical farms are farms that are built indoors and usually use hydroponic or aquaponic systems to produce crops in a controlled environment. Currently, vertical farms have an expensive initial cost to build and relies heavily on electricity for artificial light. With that being said, there are a lot of benefits and potential for the concept of vertical farms. Most of the benefit comes from the controlled indoor environment, and the fact that they can be built in more diverse areas.
There is a multitude of benefits from farming in an indoor and controlled environment. Some of these consist of year long seasonal crops, organic produce, water conservation, and land use efficiency. As vertical farms are done indoors, controlling variables such as temperature, humidity, and light exposure, allows for year long productivity for even seasonal crops that usually only grow in short time frames each year. This method of farming limits the need for herbicides and pesticides. Vegetables grown this way also saves a lot of water, only using a small percent of water that would be needed for conventional outdoor farms that lose most of their water through soil seepage and evaporation. As multiple crops are planted vertically, it is also land efficient compared to conventional farming.
As vertical farms are indoor facilities, they can be built in a lot of places where conventional farming may not be possible. This means that countries, cities, or towns that rely on imports, could potentially become more independent in growing local crops. Also, as these farms can be built closer to cities, there would be lower transport cost and less wastage due to spoilage.
Currently vertical farms are still a relatively new concept, but there are organisations that have had success in creating them in an industrial capacity. Mirai for example, which built their vertical farm in response to the 2011 earthquake and tsunami that devastated Japan. They repurposed a building that had been abandoned due to the disaster and turned it into a 25,000 square feet vertical farm. This farm can produce up to 10,000 heads of lettuce per day, which is a hundred times more productive than traditional outdoor farming. They also teamed up with GE Japan who developed their artificial lighting technology, which has altered the plant growth cycle to increase growth rates by two and a half times. Their method of farming has also reduced food wastage by 80% and it only requires approximately 1% of the water required compared to outdoor farms.
As farmland becomes scarce and food demand rises with population, there is a bright future for vertical farms. Currently most vertical farms only produce leafy greens that grow relatively quickly as they are the most economical, but future research and development could widen the variety of crops that can be harvested in these farms. Also, combining renewable energy technologies as they advance, such as wind and solar energy, could supplement vertical farms in reducing their energy consumptions, becoming zero net consumption farms, or even becoming produces of electricity through anaerobic digesters. Future research on lighting and plant growth could optimise different spectrum of lights for different plants, further increasing productivity and increasing the efficiency of artificial lighting.
Aside from strictly farming structures, there are currently conceptual designs that integrate other structures with vertical farms that could be implemented in the future. An example of this is the proposed Oasis Tower for Dubai, which is a housing complex that is designed to produce enough food to feed 40, 000 people.
There are also concepts to augment existing structures such as the Clepsydra, which can be attached onto average rooftops of existing buildings that can produce the equivalent of six acres of farmland worth of crops.