As crowded as the world's cities seem, there are still hidden unused spaces within or on the borders of many countries. However, using vertical farming techniques, controlled lighting and water basins, some countries have been able to exploit these spaces, such as Taiwan, Singapore and Argentina, each experimenting with planting on rooftops, and vacant or even enclosed sites.

With urban growth, people's requirements and needs grow more complex, while cities change the demographic and natural characteristics of the previously green spaces. This reality is becoming clearer every day, as international organizations predict that nearly 70% of people will live in cities by 2050.

Numerically, these people will occupy vast areas, with farming lands unable to meet the growing demand for food, especially in light of the migration of farmers towards cities in search of broader economic prospects or to escape desert creep, water shortages and loss of trees, as in the case of Latin America, which suffers from faltering economies, high unemployment, unpredictable weather conditions, not to mention fires and floods.

The situation is not better off in Asia. The same conditions, accompanied by climate change, have placed environmental and economic pressures on both rural and urban areas, sometimes amounting to serious threats to the food security of entire countries, especially those that import food and have a high population density. At the same time, these foods are no longer as healthy as they used to be, due to the excessive use of pesticides and chemicals made from petroleum derivatives, not to mention the 18.4% greenhouse gas emissions caused by conventional farming.

Here, it became imperative for city people and their local authorities to find an alternative to the farming lands that were consumed by the urban landscape. The alternative was a concept called “urban farming”, an experiment where government support policies combine with urban planning and the desire of city inhabitants to establish sustainable food systems.

Such alternative requires the establishment of small local farms in vacant lands and landfills for the care of local communities in cooperation with public and private entities, or vertical farming in abandoned buildings, or transforming the roofs of urban buildings into gardens suitable for growing crops, or installing aquaculture or hybrid basins, or resorting to industrial, technological and even automated processes, partially or completely.

Among the notable experiences are those developed by Taiwan, as its government is rehabilitating old infrastructure to test the concepts of vertical and indoor farming to produce fresh food. Located at capital city Taipei’s station, the 40 square-metre ‘Metro Fresh’ hydroponic farm grows lettuce under LED lighting in a sterile environment to eliminate the use of pesticides and herbicides. They use high tech equipment to regulate conditions such as light, temperature and nutrients which are most beneficial to the growth of the plants.

To increase young people’s interest in farming and benefit from their technological awareness, the government is promoting the presence of smart and vertical farms in which seeds are planted on 10 floors above each other, equivalent to one hectare of natural agricultural land, and can be as many as 100 floors, which means 10 hectares of agricultural land within 1,000 square metres.

Many intersections combine Taiwan's experience with its Singaporean counterpart. The government of Singapore provides grants and technological facilities to its citizens, and invites them to plant what they can on the roofs of their homes or in multi-storey parking lots, as the Singapore Food Agency offers these spaces in tenders for agricultural investment and crop storage over a period of 3 years.

From Asia to Latin America, specifically in the Argentine city of Rosario, in 2002 the city municipality launched an Urban Agriculture Program in seek of innovative approaches to climate change and inequality.

The program ensures that low-income people have access to vacant lands, whether public or private, and provides them with the necessary tools, materials and seeds, as well as trains them on environmentally friendly and chemical-free agricultural production mechanisms. The municipality has also established popular markets to enable urban farmers to sell their crops and home products such as pickles, sauces, juices, jams and organic cosmetics.

However, the success of these ideas is hindered by some challenges, most notably the lack of awareness among people who confuse them with other agricultural concepts such as genetic modification. Moreover, they cannot reach the required technological level, not to mention the large electricity consumption associated with the lighting systems. But these ideas promise to have significant effects if combined with knowledge, as they bring green spaces closer to people and give them an opportunity to engage in physically and psychologically useful activities, make use of ineffective spaces in crowded cities, and add some flexibility to supply chains.

Besides enhancing food security, Taiwan's smart farms contribute to stimulating the technology sector, increasing crops and maximizing the use of land, and natural and economic resources that revitalize the environment and provide a green belt that purifies the air of cities. The government in Singapore is looking to bring production centres closer to consumers, increase production by 10 to 15 times and produce 30% of the population's food needs locally by 2030. Meanwhile, in Rosario, the urban agriculture project has expanded over two decades to cover 75 hectares where hundreds of locals work to reach healthy and sustainable food production and address climate change.

References:

• https://www.euronews.com/green/2022/10/05/taiwan-is-transforming-unused-metro-stations-into-underground-vertical-farms
• https://www.weforum.org/agenda/2015/12/what-happens-when-farmers-migrate/
• https://www.weforum.org/agenda/2020/09/urban-farming-flourish-post-pandemic
• https://sustainableurbandelta.com/farmers-without-land-how-unused-urban-spaces-can-feed-our-cities/
• https://tomorrow.city/a/taiwan-vertical-farms-subway-stations
• https://www.technologyreview.com/2020/10/13/1009497/singapore-vertical-farming-food-security/