How will we eat and live in cities of the future: Urban Farming as a stepping stone to circular agriculture?
Ein Beitrag von: Kara Xenia Tucholke, Scientific Research Analyst
Circular food production — a must in an ever-growing world population
The industrial food revolution brought with it synthetically produced fertilizers and pesticides as well as farming mechanization, collectively leading to a much higher yield in crops, thus helping to feed a fast-growing population. However, this growth also has societal, economic and environmental consequences: unhealthy diets from readily available processed foods, pesticides hazardous to farmers, consumers and the environment, antibiotic resistance as well as land degradation, air pollution and waste of precious water. (1)
According to Sara Menker, CEO of the agricultural data platform, Gro Intelligence: “we could have a tipping point in global food and agriculture if swinging demand surpasses the agriculture system’s structural capacity to produce food. People could starve and governments may fall.”(2) The United Nations predicts our world population to reach almost 10 billion by 2050 (3) and it is estimated that two-thirds of that population will live in urban areas (4). Given that 80 percent of food consumption will happen in cities by 2050, urban areas have the demand power to positively influence our current, predominantly linear food production system to become circular — a change that is imperative in order to uphold our natural systems while still feeding a growing world population. According to the Ellen McArthur Foundation, a circular system encompasses: “designing out waste and pollution, keeping products and materials in use, and regenerating natural systems. In this vision, food production improves rather than degrades the environment, and all people have access to healthy and nutritious food.”(1)
Urban and circular farming together have many positive effects
Urban farms are set up in the vicinity of cities with the purpose of producing food for consumption in cities; and while this model may produce only one-third of the urban demand for food, it has unique qualities: due to the local nature of food production, consumption and disposal, transportation distances are reduced (with a significant reduction in CO2 emissions), less plastic packaging and the possibility to turn food waste directly into ecological fertilizers.(1)
High-tech greenhouses on rooftops can create synergies with the buildings they are situated on by using their waste heat in the winter and their waste CO2 to foster plant growth (6). Aquaponics fertilizes the soils of leafy vegetables with the waste water of fish farm tanks, providing a solution to declining fish populations as well as the use of excess water and synthetic pesticides (7,8) — examples for this are the ECF farm in Berlin (9) as well as BIGH’s Ferme Abattoir in Brussels, which combines this technique with the use of a high-tech greenhouse on their rooftops to raise fish, grow fruits, vegetables and herbs in a closed and zero waste loop (10).
Algae — food of the future & one of many examples for an innovative agriculture
The vertical seafood farm, GreenWave, off the coast of New England, makes use of nutrients run off from nearby farmland in order to feed its vertical seafood and kelp production on 0,4 hectares of water (11). Algae may prove to be healthy and protein-rich foods of the future, growing both quick and abundantly as opposed to land crops (12). Already the engineering company MINT produces systems that grow micro algae industrially as well as on interior walls or house facades (13).
Through innovation, agriculture can be expanded to habitats that are usually hostile to crop growing: The “Floating Farm” on Rotterdam’s river Nieuwe Maas aims at supplying locals with fresh milk, while using cow waste to fertilize feed crops and create energy (14). The “Growing Underground” is situated in an old air-raid shelter 33 meters under London, growing vegetables and herbs while using 70 percent less water (15). The German Aerospace Center (DLR) has developed a “Vertical Farm 2.0”, a modular-built multi-story farm building, which efficiently grows crops without soil or pesticides (16). Still, such indoor practices may use a lot of energy for lighting and heating as well as liquid fertilizers.
Whereas outdoor farming, like rooftop farming, may not yield as many crops, it still provides socio-environmental benefits: cleaner air, reduction of the heat island effect, beautification of urban landscapes, improved water retention of soil and reduced flood risk.
Urban farming as socialization
One positive extended effect that a relocation of food production to our urban areas brings is the involvement of citizens, improvement of the social fabric and a reconnection with our food. (1) The transformation that urban farming can bring to a repressed community in Detroit was shown by Devita Davison at a TED conference in 2017: obesity and malnutrition rates dropped, new business opportunities emerged and a new sense of community through collaboration and learning arose (17). Specht et al.’s study on the acceptance of new farming approaches found that such new farming practices bring major benefits like “educational effects, revaluation of city districts, efficient resource use, exploitation of new protein sources and strengthening of local economies.”(5)
Vegetables are gaining ground — seasonal, local and organic
The diet in wealthy (18) and developing countries (19) is changing from meat consumption towards a growing preference for plant-based nutrition. There is also a higher demand for farmer markets and with that, local, seasonal and organic produce. This, in turn, increases the connection between farmers (as suppliers) and consumers and will drive economic sustainability since farmers get a considerably larger share of profits when selling on markets. Since supermarket produce is usually harvested two weeks earlier in order to still stay fresh in-store (20), eating seasonally gives consumers a more nutritional and diverse diet (21). An observation has been made that in uncertain economic times, consumers tend to buy regional traditional food brands which appeal to nostalgia and carry emotional value (22).
Technology — a big part of the future of agriculture
Several farming practice innovations have been developed to address the consequences of climate change such as reduced amounts of land (from soil sealing/ degradation and rising sea levels) and water resources as well as extreme weather events (5). Investments in food production and enabling regulations are bound to lead to breakthroughs in agriculture and the emergence of improved food systems. Artificial Intelligence (AI) and blockchain technology can support the food system revolution by making supply chains transparent and aiding farmers with real time updates about crops and food distribution (1). Investing in agriculture with its emerging technologies can prove to be lucrative, but is also important in the fight against world hunger (23).
First steps to a circular agriculture
Growing all food locally is not a realistic scenario; rather, cities should aim to make their food supplies resilient by sourcing from a diverse set of local, regional and global food sources, according to where the food types grow best (1). In the face of climate change and weather extremes leading to droughts and water runoff, transformation of our current industrial, harmful agricultural system seems inevitable (24). In the long run, this system has to turn circular in order to have a real positive impact. Urban farming can be a first important step towards circularity, while bringing about several positive impacts to society and economy.
1. Ellen Mcarthur Foundation. Cities and Circular Economies for Food. https://www.ellenmacarthurfoundation.org/assets/downloads/Cities-and-Circular-Economy-for- Food_280119.pdf: Ellen Mcarthur Foundation; 2019.
2. Menker S. A global food crisis may be less than a decade away [Internet]. [cited 2019 Dec 4]. Available from: https://www.ted.com/talks/sara_menker_a_global_food_crisis_may_be_less_than_a_decade_away
3. United Nations. World population projected to reach 9.8 billion in 2050, and 11.2 billion in 2100 [Internet]. UN DESA | United Nations Department of Economic and Social Affairs. 2017 [cited 2019 Dec 17]. Available from: https://www.un.org/development/desa/en/news/population/world-population-prospects- 2017.html
4. Ritchie H, Roser M. Urbanization. Our World Data [Internet]. 2018 Jun 13 [cited 2019 Dec 17]; Available from: https://ourworldindata.org/urbanization
5. Specht K, Zoll F, Schümann H, Bela J, Kachel J, Robischon M. How Will We Eat and Produce in the Cities of the Future? From Edible Insects to Vertical Farming — A Study on the Perception and Acceptability of New Approaches. Sustainability. 2019 Jan;11(16):4315.
6. Montero JI, Baeza E, Heuvelink E, Rieradevall J, Muñoz P, Ercilla M, et al. Productivity of a building-integrated roof top greenhouse in a Mediterranean climate. Agric Syst. 2017 Nov 1;158:14–22.
7. Love DC, Fry JP, Li X, Hill ES, Genello L, Semmens K, et al. Commercial aquaponics production and profitability: Findings from an international survey. Aquaculture. 2015 Jan 1;435:67–74.
8. Blidariu F, Grozea A. Increasing the Economical Efficiency and Sustainability of Indoor Fish Farming by Means of Aquaponics — Review. Sci Pap. 2011;8.
9. Ufer M, Liebfrauen KS, Berlin. Aquaponik: Ist das die Fischzucht der Zukunft? FAZNET [Internet]. [cited 2019 Dec 17]; Available from: https://www.faz.net/1.6379499
10. BIGH Farms — Rooftop Aquaponic Farms [Internet]. 2018 [cited 2019 Dec 4]. Available from: https://bigh.farm/
11. Our Model [Internet]. GreenWave. [cited 2019 Dec 17]. Available from: https://www.greenwave.org/our-model
12. Tiwari B, Troy D. Seaweed Sustainability [Internet]. Elsevier; 2015 [cited 2019 Dec 17]. Available from: https://linkinghub.elsevier.com/retrieve/pii/C2013012836X
13. Home [Internet]. MINT Engineering GmbH. [cited 2019 Dec 17]. Available from: https://www.mint-engineering.de/en/home/
14. De Farm | Floatingfarm [Internet]. [cited 2019 Dec 17]. Available from: https://floatingfarm.nl/de-farm/
15. Home [Internet]. Growing Underground. [cited 2019 Dec 17]. Available from: http://growing-underground.com/
16. Future Markets Magazine. Megatrend Urban Farming [Internet]. Markets&Technology. 2016 [cited 2019 Dec 4]. Available from: https://future-markets-magazine.com/de/markets-technology/megatrend-urban-farming/
17. Davison D. How urban agriculture is transforming Detroit [Internet]. TED2017; 2017 [cited 2019 Dec 4]. Available from: https://www.ted.com/talks/devita_davison_how_urban_agriculture_is_transforming_detroit
18. Mintel Press Team. US non-dairy milk sales grow 61% over the last 5 years [Internet]. 2018 [cited 2019 Dec 22]. Available from: https://www.mintel.com/press-centre/food-and-drink/us-non-dairy-milk-sales-grow- 61-over-the-last-five-years
19. Waite R. 2018 Will See High Meat Consumption in the U.S., but the American Diet is Shifting [Internet]. World Resources Institute. 2018 [cited 2019 Dec 22]. Available from: https://www.wri.org/blog/2018/01/2018- will-see-high-meat-consumption-us-american-diet-shifting
20. Modarres M. Why you should shop at your local farmers market [Internet]. [cited 2019 Dec 4]. Available from: https://www.ted.com/talks/mohammad_modarres_why_you_should_shop_at_your_local_farmers_market
21. Michael D. Five benefits of eating seasonal produce | Articles | Mount Nittany Health System [Internet]. 2018 [cited 2019 Dec 22]. Available from: https://www.mountnittany.org/articles/five-benefits-of-eating-seasonal-produce
22. Mutenthaler C. Quo vadis — die Zukunft unserer Lebensmittelversorgung: Konsumententrends und Zukunftsanforderungen. Diplomica Verlag; 2014. 201 p.
23. Deutsche Bank. Agricultural investments for more productivity and sustainability — Deutsche Bank Responsibility [Internet]. 2019 [cited 2019 Dec 22]. Available from: https://www.db.com/cr/en/concrete- Agricultural-investments-for-more-productivity-and-sustainability.htm
24. FAO — News Article: Disasters causing billions in agricultural losses, with drought leading the way [Internet]. [cited 2019 Dec 22]. Available from: http://www.fao.org/news/story/en/item/1106977/icode/