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Cultivating change in connection with innovation and legislation

Growing food in the built environment: A strategy for improving sustainability in Stockholm Royal Seaport

Stockholm Royal Seaport has the ambition of transforming grey infrastructure into edible green spaces by growing food on rooftops, facades, and underground spaces. With this and other actions, the district is paving the way towards a sustainable future.

Stockholm Royal Seaport is a former industrial area that has been transformed into one of the largest urban developments in Europe. With the provision of 12,000 new homes and 35,00 working places, significant densification is accompanied by high sustainability ambitions such as achieving carbon neutrality by 2030. The district was appointed by Stockholm City Council as a “sustainability-profiled area” with the mission of testing and developing innovative solutions and governance processes. The ultimate goal is for the district to act as a forerunner for sustainable urban development. As a test-bed district, it is possible to enforce sustainability targets and requirements to construction companies and employ monitoring tools to track the performance of the development. These mechanisms resulted into high compliance in energy performance, mobility, urban greenery, and waste management.

In 2019, a report explored the question: “if we were to produce 10% of food consumed in cities, what spaces could be used for that?” The report identified potential areas, surfaces, and dark spaces in the city that could be used for urban farming (Stockholms Stad, 2019). This inspired the policy target of creating conditions for productive ecosystem services in the district (Stockholms Stad, 2021) and highlighted the need to assess the potential of urban agriculture to address sustainability concerns. Maria Lennartsson, who is R&D Coordinator in Stockholm Royal Seaport and Project Manager for the Stockholm pilot on urban agriculture, says:

Green walls in Stockholm Royal Sea Port, Stockholm, Sweden
Photos: Jansin & Hammarling/flickr.com; Eric Cung-Dinh/flickr.com

We did a study a few years ago that challenged our way of thinking. It was about mobility, and we began by asking ourselves: if we forget everything else and focus on how to plan a city with the best mobility solutions, what would that look like? What we got out of this study was planning principles that can be applied. And that is precisely what we do here. If we think about urban agriculture and the potential of growing food in cities, what would that look like and what planning principles can we develop?

In 2022, with the support of the European Joint Program Initiative,

Transformative Capacities in Energy, Food and Water – TANGO-W project. Financed by the Swedish Energy Agency grant number 52849-1

an in-depth study began which explores the viability of including food production as a requirement for developing a particular area of the district. The process includes visionary workshops to discuss the barriers and opportunities to grow food in cities and how to embrace it as “urban infrastructure.” One key element of growing food in the district is the ambition to go beyond the cultivation of green leaves to include the growing of caloric food, which is paramount for increasing the resilience of cities regarding food security.

To this end, a working group and several workshops have taken place to discuss the possibility of farming in cities through the implementation of green roofs, greenhouses on the tops of buildings, agri-walls on the facades, and growing mushrooms and cultivating fish in dark spaces. Regenerative design has been a leading concept in these discussions. This concept mimics natural ecosystem processes and builds on a systemic and integrative approach to meet societal needs while preserving nature’s integrity. These workshops include the participation of civil servants from different departments (e.g., water, energy, waste, land management, parks, public health) and private sector actors (e.g., developers) as well as civil society. Together these actors share their ideas about the potentials and challenges of effectively introducing farming in urban spaces. From Maria’s perspective:

Conceiving urban agriculture from the perspective of productive ecosystem services and regenerative design offers a means to return to the environment a little bit of what we take.

There are several opportunities to implement such an ambitious project in the district. From a legislative perspective, the sustainability policy safeguards the work of testing innovative sustainable solutions in Stockholm Royal Seaport. The implementation of such piloting activities over the last 12 years has been characterised by cooperation across different municipality sectors. Beyond this, great connection with large and heterogeneous networks including NGOs, businesses, researchers, and developers provides a rich environment to debate alternative means to grow food in cities. The strong power of the municipality is an advantage as there is the possibility to influence the allocation of land process to developers, for example, by introducing strict requirements in the land sale contracts. In addition to these aspects, Stockholm has a long history of urban farming with several allotment gardens located across the city, but still not enough to fulfil the high demand from people to grow food in cities. As Maria Lennartsson says:

Reimagining allotment gardens in dense urban areas can create ways of having modern social recreative possibilities including recreative gardening and food production.

Furthermore, the growing global awareness about the importance of establishing short-supply food chains fostering resilience and self-sufficiency, especially in tandem with climate change, COVID-19, and the war in Ukraine, is reflected in the market, which has experienced an increased number of small and medium-sized enterprises and startups focusing on producing food in cities (Butturini and Marcelis, 2020).

Among the barriers, the novelty of growing food in the built environment can be perceived as a risk for some stakeholders, as the dissociation between agriculture and cities is still present in the minds of some residents as well as policymakers and developers. This poses some challenges in raising interest within the planning administration to enable the incorporation of a strategy for food production in the upcoming land allocation processes, as well as to anchor the idea of growing food in buildings among the developers who may focus on the risks rather than the benefits of urban agriculture.

Despite the technical, legislative, and governance barriers that need to be addressed to effectively grow calories in cities, there is a crucial need to discuss and demonstrate urban agriculture as a desirable urban function that can shorten food supply chains, improve biodiversity, enhance social inclusion, and improve community life. These are key components in the political debate about how to transform our cities from dysfunctional to functional ecosystems that work towards sustainable and resilient urban futures. Visions are seeds of change; thus, they need to be cultivated, as we need to change current mindsets to be able to meet global environmental goals and live more in harmony with nature. As Maria Lennartsson says:

I hope that urban agriculture will be an integral part of the upcoming developments and that we also influence the policy paper or the urban agriculture plan that the city is currently developing.

Box 2: Stockholm Royal Seaport: Summary of opportunities

The global awareness on the importance of establishing short food supply chains supports urban agriculture as a mean to strengthen urban resilience and self-sufficiency
The district employs an innovative governance model characterised by experimentation of sustainable solutions and co-creation with a broad and heterogeneous network (e.g., NGOs, businesses, researchers, developers)
The vision of including food production in cities follows Stockholm’s tradition in urban farming with urban allotment gardens.
Gardening has become a meditative practice for urban dwellers during COVID-19 as a mean to reconnect with nature.

Box 3: Stockholm Royal Seaport: Summary of challenges

It takes time and effort to raise interest within the planning administration to enable incorporating urban agriculture in forthcoming land allocation processes.
Urban agriculture initiatives may be met with resistance or indifference from political leaders.
Developers and other stakeholders may focus on risks rather than benefits, making it difficult to implement food production into the urban environment.
High land costs threaten the implementation of agriculture in cities.

Växthuset på Berga: Growing tropical fruits in Stockholm

Yes, it is possible to grow tropical fruits in the Stockholm Region. Björn Oliviusson is an entrepreneur who grows bananas and papayas in Southern Stockholm challenging the norm that tropical fruits cannot be grown in cold climate.

Växthuset på Berga is a greenhouse built in 2012 as part of Björn Oliuvisson’s PhD. The greenhouse is 80 m² and takes the shape of a dome with a height of 4.5 m at the highest point. It is built with five layers of polycarbonate—two thick layers in the external part of the greenhouse and three thin layers inside—that create four different channels of air, providing excellent insulation. Inside the greenhouse, an aquaponic system enables the cultivation of tropical fruits (e.g., bananas, papayas, vanilla, sugar cane). The greenhouse has been attracting the attention of many people, and since its opening has hosted approximately 18,000 visitors from around the world. Its proximity to energy sources from a local school allows for the system’s functionality which shows high productivity compared to soil-based production. The record productivity of 17 kg/m² of bananas contrasts with the average output of 5 kg/m² of bananas cultivated with traditional soil-based technologies. As Björn says:

Björn Oliviusson, owner of Växhuset på Berga, Stockholm, Sweden

(…) If we were to start some sort of production indoors in an urban setting, it's likely that we reach production volumes that are at least close to those commercial quantities.

The products are well-received in the market; local shops acquire most of the fruits which are slightly processed (peeled, cut, and frozen) before being sold. Fish are a fundamental part of the aquaponic system as they provide nutrients to the plants through their waste; however, the fish are not commercialised as this would demand larger investments and infrastructure to comply with rules and legislation to slaughter them. Therefore, only the small fish are sold for aquariums. Nevertheless, the potential of growing fish should not go unnoticed. As Björn says:

In aquaponic systems, it is possible to farm many different species of fish, even in the same tank. By creating multispecies production, we will be able to utilise many left-over products as feed, or to convert them into feed (insects, mushrooms), creating food webs within the tank. This will enable us to close the nutrient loop even more.

The high temperature achieved in the greenhouse has affected the choice of crops to be cultivated. Rather than investing in technologies for regulating the temperature, which would enable growing vegetables (e.g., cucumbers, tomatoes, green leaves), Björn opted for tropical fruits that grow well in the greenhouse environment. Besides having high tolerance for shifting temperatures, these species also easily adapt to changes in air humidity and light, and the workload is lower as one person can easily manage the tasks needed to maintain the greenhouse. Compared with cultivating vegetables, farming tropical fruits is less demanding, and the running costs (maintenance and pest control) are much lower. The disadvantage is that these fruits need to grow longer, between three and five years, before providing economic returns.

Capitalising on the advantage of flexible working conditions, Björn also dedicates his time to teaching and consultancy. He is a mentor in a professional course on aquaponics and a consultant providing several customers with advice on how to grow food with aquaponics. In addition, he participates in several events spreading the knowledge about aquaponics and the urgent need to embrace this technology considering the negative effects of climate change on highly productive areas. For example, places such as Almeria in the southeastern part of Spain used to produce a large amount of the vegetables consumed in Europe, but food production in the area has suffered due to severe drought.

Closed aquaponic systems require one-tenth of the amount of water of soil-based production, and they use no pesticides as beneficial insects are used to naturally counteract eventual pests. Nevertheless, it has been a slow process to raise awareness of enabling short food supply chains and influencing the market to embrace aquaponics in food production. The European legislation is an obstacle as food grown in aquaponic systems is not granted organic labels, exacerbating the competition of the products with extremely cheap imports. Introducing aquaponic systems would require a change in the different systems for growing food, but Björn sees the resistance to change as a concern:

Just a few weeks ago it was in the news about the drought in the High Plains in the United States. But it was known that the need to water these giant fields would come for at least 20 years. The only thing that changed was that it happened earlier than predicted. So that is a problem. If people were aware and more effort, more money would be invested to find alternative solutions for urban food production it would be much easier (…). As we say in Sweden “you need to have a knife on your throat” to realise the need for change; otherwise, people do not react.

Another mental barrier to overcome is accepting that new systems such as aquaponics may not offer maximum profitability immediately, but they create several benefits in the long run. As the example above shows, traditional means of growing food are becoming more expensive with the rising need for water for irrigation and increasing labour and fertiliser prices. This trend suggests that the prices of imports will increase, and food shortages may soon become a reality. This dark future may be the entry point for the success and acceptability of aquaponics.

One future vision is to embrace food production with greenhouses and aquaponics in cities. These technologies have the potential to create a fully closed-loop system that can be placed anywhere (e.g., between buildings). In addition, the greenhouses do not demand soil and can function with waste heat, and available water from the buildings, so they fit nicely into urban environments. Nevertheless, there is a need to demonstrate in a convincing manner that this system is a viable solution for improving the sustainability of our food systems. As Björn suggests, showcasing a highly productive and economically viable greenhouse using aquaponics in a city centre could be an eye-opener for politicians, urban planners, and entrepreneurs on the advantages of supporting short food supply chains. In addition Björn says:

The benefits for society would be huge if it were to be implemented on a large scale. It will easily gain acceptability because plants, fishes, flowers are things that most people consider positive, and they would have increased self-sufficiency when it comes to food. So, I think it will increase. I just hope it will increase quickly enough.

Box 4: Växthuset på Berga: Summary of opportunities

Aquaponics systems deliver higher yields compared with traditional soil-based technologies for growing food.
Greenhouses and aquaponic systems can be easily implemented in cities, as they can be built in between existing buildings, use heat waste and available water, and also provide food and pleasant environments for people.
Aquaponic systems do not make use of pesticides and use only 10% of the amount of water compared to soil-based technologies.

Box 5: Växthuset på Berga: Summary of challenges

The market has been slow in uptaking aquaponics technology.
European legislation does not grant ecological, organic labels to food grown with aquaponics, thus hurting its competitiveness.
New skills and competencies are needed to enable the implementation and management of aquaponic systems in the built environment.
Growing fruits in aquaponic systems is a long-term investment as many years are required before the production can be commercialised.