Food Security and Circular Cities: Paradigmatic Shifts, Geographical and Temporal Scales, and Participatory Governance Support to Facilitate Transitions Towards ‘Urban Sustainability’

Abstract

This article explores how the principles of circularity, applied to urban food systems, could contribute to catalysing a transition towards more sustainable cities, working on the premise that food security is a key pillar of urban resilience. In order to do so, it critically examines (i) circularity in the context of urban regeneration and why focusing on food could help to understand the sociopolitical and ecological dimensions of circularity; (ii) the geographical and temporal scales of urban circularity; and (iii) how ‘barometers of circularity’ could be built and integrated into participatory urban governance processes to support urban ecological transformations.

1. Introduction

The un-sustainability of our cities has been generating concerns for a while. Statistics on cities [1] reveal that, despite occupying 2% of the land, cities generate nearly 70% of all CO₂ emissions, produce an enormous amount of waste (60%) and pollution and use 80% of energy. The New Urban Agenda, announced at Habitat III in response to Sustainable Development Goal (SDG) 11, has called for a new paradigm on which to base a reform of our governance systems so that sustainable urban and territorial development can be integrated as essential components in the achievement of sustainable development [2].

In this article, we suggest that such a new paradigm could build on insights from research on ‘circularity’. Focusing on waste and on the inefficiency in natural resource management as the main ‘urban problems’ is indeed an imperative. Cities do need to reduce the magnitude of their ‘ecological footprint’—which, as [3] explains, “is the amount of land required to support people’s lives and lifestyles which, ideally, should not exceed the productive land on earth. The richer the city, the more it tends to draw on nature’s bounty from across the world rather than its own local hinterland” [3] (p. 86). As our populations grow and global consumption increases, cities’ ecological footprints have been forecast to triple by 2030, whilst a third of the food that we produce is currently being wasted. It is essential that we slow down this tendency and that we envisage new ways of meeting our needs.

The principle of a circular economy (CE) [4] is that the economy, so far based on the linear principles of use–produce–throw away, could be transformed so that it reduces waste to possibly zero, uses renewable energy and adds value to by-products. Attempting to make a city circular works on the same basis. However, this seemingly quite straightforward reduction and reuse of waste generates all sorts of sociocultural, ecological and political implications in terms of urban governance and transformation.

For [5], the CE encourages us to completely reimagine a ‘well-performing city’ as a system that provides residents with their basic needs for water, food, energy and shelter in an efficient way. In such a context, the ‘indicators of success’ would therefore not only shift to a zero-waste type of urban development but would also reflect the enhanced level of responsibility for the local environment and of infrastructure support taken by urban communities. Although research on the CE has approached the challenge of minimising cities’ waste in various ways—for instance, through life cycle analysis, cradle-to-cradle techniques, industrial ecology or new business models [4]—CE principles, in fact, go well beyond reducing and reusing waste and adding value to by-products.

In order to apprehend better the full potential of circularity, this article undertakes a critical exploration of three of its particularly relevant aspects in the context of urban transformation towards sustainability, advocating for an interdisciplinary, participative and ecologically regenerative approach, itself catalysed by an urgent concern—that of urban food security.

First, it explains how focusing on the urban food system, as a practical point of departure from which to build circularity, could be particularly relevant: these have been shown to be core to urban resilience, and the operationalisation of circularity principles will need to be incremental, with a strategic starting point. Working on such a practical ‘case study’ will highlight the need for a critical discussion of the disciplinary–paradigmatic boundary of the CE.

Secondly, the centrality of the food system in the context of urban circularity encourages a discussion about the geographical scale at which such circularity is being designed, critically questioning both (too) small-scale preferences for sustainable food production and globalised food trade. The incremental and participatory nature of urban transitions towards more resilience and circularity, in turn, simulates a discussion of temporal considerations in the CE.

Thirdly, since CE principles fundamentally question the linear processes on which economic activities rely in view of pursuing economic growth, this article concludes on the urgent need to reform indicators of ‘economic success’. The third part therefore presents alternative barometers of circularity, emphasising the need to apprehend circularity within the context of an ecological–economic urban ecosystem. It also highlights the ways in which participatory circular food systems (CFS) could act as a catalyst to create participatory urban governance processes at the level of all (interconnected) urban activities.

2. Urban Circularity: A Paradigmatic Dialogue Between Theories and Needs

This section explores why a focus on food systems could help in apprehending urban circularity through a paradigmatic lens that is better adapted to the cities of the future.

2.1. Circularity in the Context of Urban Transformation and Regenerative Development

Making cities more circular has often been regarded as a prerequisite in making them more sustainable. For [6], it is “taking a circular approach to development [that] will enable the resource-efficient, waste-free, ecologically regenerative and continual renewal of the city” [6] (p. 8).

The notion of circularity is most often linked to the need to minimise or eliminate waste in view of both making our resource management more efficient and of addressing the ‘waste’ problem, which, in the case of cities, is particularly urgent. For long, ‘circularity’ has been approached from an industrial ecology (defined by [7] as a study aimed at understanding the circulation of materials and energy flows) or from a business model perspective ([8] defines a circular business model as one that facilitates the creation of added value by reusing the economic value retained in products in the creation of new products or services).

In this paper, we suggest the exploration of circularity from an urban development perspective and its use to facilitate urban transformations towards greater sustainability and resilience—considering a sustainable city as a self-sufficient economic, social and environmental system [9] and a resilient one as a city that is prepared for uncertain futures [10].

The suggestion of such a critical paradigmatic reflection on the notion of circularity is intended to address a few important gaps identified by CE researchers [11,12]. Such ‘gaps’ include a lack of social dimensions and not enough importance given to consumption (a major focus being placed instead on the production and provision of goods) but also to the context within which the CE is to be operationalised. In [11], it is stressed that, because circular activities, products and services are under-valued by the market, it is difficult for them to compete with existing systems of provision. The author therefore recommends moving away from an economic, market-centred approach to circularity and to investigate, instead, a developmental approach to it. As she explains, “Circular Development (CD) territorialises circularity (considering both context and scale) and its impacts on urban systems, activities and infrastructure. It incorporates social dimensions, recognising the impacts of CD on society (and vice versa). It integrates political dimensions, recognising the important role governments, industry, business and communities play in delivery” [11] (p. 15).

If CD responds to some of the shortcomings of the CE when applied to cities, we suggest that the concepts of ‘urban metabolism’ and ‘urban ecosystem functions’ (UEF), could also help to integrate ecological dimensions into ‘urban circularity’. Thus, in addition to the prime notion of waste taken into account in circularity principles, we suggest also addressing the damage caused to the life support ecological basis that we depend upon as a type of ‘negative by-product of our activities’. This directly connects the notion of circularity to that of ‘regenerative development’—focused on the linkages between a plurality of stakeholders and nature and between urban systems and ecosystems [13]—hence addressing the need to create stronger links between symbiotic and regenerative sustainability frameworks and the operationalisation of circular principles in cities highlighted and carried out (through a list of resulting strategies) in [14]. Such a systemic perspective combines the CE and urban metabolism, but also culture and society [15]. An ecological–economic paradigm could provide a helpful alternative to develop new production and consumption chains, the rise of complex networks and the value-added to rural and regional places [16].

To illustrate how CD could be enhanced by the notion of regenerative development, we focus next on the study of urban CFS as key to urban sustainability and resilience.

2.2. Circular Food Systems: A Practical Starting Point to Operationalise Urban Circularity

This section focuses on ‘where to start?’ (when trying to make a city circular). Here, we explore how making the food system circular could act as a key catalyst for sustainable change in an urban context, working from the following key points.

(1)

Urban food production is connected to many aspects of urban activities and therefore can have a large impact through interconnections. Such interconnections were illustrated in [17], which extended CE principles in food systems transformation to address human, environmental and economic health. ‘Food systems’, as defined by Ericksen (2008), include the full value chain of producing food for human consumption, from agricultural production, through transportation, handling, processing, storage, distribution and consumption, to waste management and disposal [18]. As [19] explains, “Food is an interconnected urban infrastructure that has to be designed and managed in a circular way” [19] (p. 5) through policies that put food at the core of a new series of change that will provoke a domino effect of sustainable solutions. Improving urban food systems (FS) as catalysts of urban transformation towards greater resilience facilitates the integration of ecological and social dimensions in the CE, thanks to the systemic nature of food.

(2)

In addition, food is one of the most important human basic needs, which was unmet or ‘in crisis’ during the COVID-19 pandemic. In this context, ref. [20] analysed the impact of COVID-19 on food security and nutrition: the various lessons learnt draw attention to the centrality of food in urban transitions. In attempting to make cities more sustainable, we must therefore highlight the fact that jeopardised food security is symptomatic of a failing economic system. As [21] concludes in its policy recommendations, research on urban food security needs to evolve towards a more holistic sustainability policy discourse, and urban food security may be better positioned from a sustainable urban development lens rather than an agricultural lens. The sustainability and resilience of an urban environment is therefore closely linked to the resilience of FS, defined in [22] as the capacity over time of an FS and its units at multiple levels to provide sufficient, appropriate and accessible food to all, in the face of various and unforeseen disturbances.

(3)

As [23] highlighted, food is also one of the greatest contributors to climate change. At national levels, states still use food production to feed economic growth in a linear way, making food a priority to tackle if we are to change our modes of production.

(4)

The urban scale is also critical since 80% of the food demand comes from cities. We therefore need to rethink how we produce the food that we need. Both the COVID-19 pandemic and the food and fuel price hikes of 2007–2008 triggered the reorientation of agri-food, which stimulated the development of alternative economy models and, at their centre, the redefinition of agriculture articulated around sustainability, security and governance.

(5)

The question that we next address is how to critically build on existing examples to provide a fuller approach to CFS that triggers a transformation towards urban sustainability.

2.3. Examples of Circular Food Systems

Numerous initiatives have already been undertaken to make urban FS more circular.

The literature focuses, for instance, on eco-innovative solutions (EIS) for waste that “innovate processes in relation to the management of waste as a resource” [24] (p. 12) and address the problem of limited urban space. The literature also provides examples of CFS focused on the creation of innovation food hubs that, for instance, facilitate the integration of water, energy, food and built systems and, through their connection in a network, would enable various stakeholders to collaborate to repurpose waste. These hubs could be imagined as “co-working spaces as well as low-cost platforms for innovators and entrepreneurs” [5] (p. 91). Connecting these hubs together, as well as with resilience corridors that would connect different parts of the city (urban and peri-urban; historic downtown and peripheral areas, etc.), could help towards the creation of regenerative cities [15].

Ref. [17] gives examples of food hubs as place-based food organisations (e.g., Food Exeter and the Bristol Food Network) that focus on generating a collaborative approach to creating new routes to market—enabling small-scale local food producers to access new consumers. The design of such regenerative food systems follows the principles of (i) closing loops (using renewable energies, returning biological nutrients into natural cycles and reusing materials); (ii) celebrating diversity and cooperation through community-supported agriculture; and (iii) generating ‘place-based value retention’ (as alternatives to linear agri-food models dominated by large producers and retailers).

Explorations of the specific aspects of urban agriculture (UA) that can be used to implement urban circularity have been carried out by various researchers. Ref. [25] explores how various types of waste (wastewater, organic waste transformed into compost, reclaimed building materials, etc.) could be used in a plethora of circular UA projects as parts of the COST Action programme CA17133, emphasising the particularly circular nature of UA (which systemically links water energy and waste). Ref. [26], in turn, focuses on UA in terms of social innovation (e.g., community rooftop gardens or social cooperative farms, with ‘community-managed activity towards community building’ or ‘local and organic production creating inclusive jobs’). The authors also explore technological innovations (examples include high-tech greenhouses, indoor farming or open-air rooftop gardens, including the use of protected soil-less production with integrated heat and water recirculation and resource-efficient LED production). The economic dimensions in UA innovations include new business models and closer interactions and solidarity in economic practices.

In line with the European Bioeconomy Strategy [27], which supports CE activities related to nutrient looping, industrial strategy and climate policy, the EMF emphasises that “achieving these ambitions would allow cities to move from passive consumers to active catalysts of change, and generate numerous benefits” [27] (p. 12)—including financial savings, reducing annual greenhouse gas emissions, avoiding the degradation of millions of hectares of arable land per year, creating new jobs and improving human health.

3. Circular Food Systems: A Reflection on Geographical and Temporal Scales

In this section, we explore the geographical and temporal scales at which CFS could take place. One important contribution of circularity has been to trigger a reflection on what defines waste. Questioning the ‘boundaries’ that separate waste from valuable resources has, in turn, shaken the boundaries and scales of CFS and food security, both in spatial and temporal terms.

Ref. [28] describes waste as “what is worthless or unused for human purpose: it is a lessening of something without an apparently useful result” [28] (p. 50). Extending this definition, ref. [29] adds that “there are waste things, waste lands, waste time, and wasted lives” [29] (p. 146), highlighting the spatial, temporal and even ideological dimensions of the concept. Ref. [30] deepens the reflection on waste in an urban context, extending it to the notion of a ‘waste landscape’, defined as actual waste (e.g., municipal solid waste, sewage), wasted places (e.g., abandoned and/or contaminated sites) and wasteful places (e.g., parking lots). Waste landscapes [31] can thus be synthesised as ‘wastescapes’—a holistic concept that includes scales regarding material circularity but also territorial dimensions and that encompasses spaces for opportunities to develop sustainable urban regeneration [32,33,34]. As residual spaces, wastescapes are therefore of particular relevance in CD since such waste needs to be transformed or ‘reinvented’, bringing wastescapes to the centre of the urban transition debate. Peri-urban areas can represent such vulnerable territories. As transition zones from urban to rural, they display chaotic sprawl and are often at the core of socioeconomic change and spatial reorganisation.

The ‘transitioning’ motivated by the redefinition of waste and by extending the geography of circularity also extends to temporal considerations, since the transformation of wastescapes, for instance, is at the very core of the long-term transition towards urban sustainability triggered. Both geographical and temporal scales therefore need to be taken into consideration.

3.1. Reflection on the Geography of (Urban) CFS

This section critically explores the boundary of the ‘circular city’ when it comes to waste management, food production and food security.

3.1.1. Using the Inner-City Space Efficiently—‘Localising CFS’

We mentioned earlier the relevance of the city scale in the context of a reflection on circularity and food security. This focus on (and preference for) the local scale was largely motivated by the fact that “Global food systems dynamics have been recognised as major contributors to the degradation of ecosystems, the generation of GHG emission and public health concerns” [4]. Some European cities have started to design urban food strategies (e.g., Milan, London, Malmö, Ghent, Vitoria, Lisbon) [35,36]. Altogether, such strategies in metropolitan areas have recently highlighted “the need to re-localize production–consumption systems through shorter, more efficient supply chains, as a means of promoting sustainable urban development via place-based approaches” [37] (p. 9) and to improve the local ecosystem’s health.

Such efficiency can be derived from small-scale agriculture based on permaculature, agro-forestry or, more generally, agro-ecological methods. Ref. [38] demonstrated that small-scale agriculture in fact generates higher yields than extensive industrial agriculture, whilst [39] investigates how agro-ecology, which currently provides 15 to 20% of the global food, could help cities to reach a state of food self-sufficiency. Various attempts to ‘sustainably intensify’ agriculture [15] acknowledge the need to try to obtain more from a smaller land surface, especially in cities.

Eco-localism [14] applied to urban FS has resulted in the exploration of various types of short food supply chains (SFSC), whose main characteristic is the “capacity to re-spatialize food, allowing consumers to make value-judgements about the relative desirability of foods on the basis of their own knowledge, culture and experience” [40] (p. 3). SFSC allow considerable reductions in CO₂ emissions and save energy from unnecessary transport. If food in the United Kingdom was produced and consumed locally, the CO₂ emissions would be reduced by 22% [41]. The ‘distance saving’ is also social, since SFSC “enable valuing the relationships between producer and consumers, showing the origin of food” [40] (p. 3).

In Tokyo, ref. [42] demonstrated the benefits of having urban farms in cities, since these are abundant in underutilised organic waste. The efficiency motive associated with focusing UA on the local scale [15] also stresses the fact that a more place-based eco-economic model generates ‘eco-effective entrepreneurship’—which regenerates the maximum added value by redesigning processes so that every output can be an input for a future product. This values the ‘action–habitat’ notion, i.e., “the area for which people feel responsible and the reciprocal movements it generates since the care for the well-being of a city goes hand in hand with the care given to a neighbourhood” [43] (p. 39).

3.1.2. Extending the CFS to the Periphery

Aimed at improving food security and facilitating transitions to more sustainable and resilient cities, the creation of CFS aligns with ‘food movements’, which, born in the United States, emerged from a food-insecure system that had become dependent on agro-industry, with a strong impact on health [44]. Through the process of the re-spatialisation of food systems, “a new interest for re-integrating agriculture into urban areas has emerged in Western cities” [45] (p. 2). In practice, this meant that many UA initiatives emerged within the city. However, peri-urban agriculture also attracted interest, especially in the context of fast and uncontrolled urban expansion. As [24] (p. 11) stresses, “urban expansion is expected to take place on soils of relatively high agricultural productivity (deltas, river valleys…) until 2030. In response to the urgency to declare a global restriction against urban encroachment on high quality soils (…) circularity processes could contribute to regenerating wastescapes such as peri-urban areas” (within 20 km of cities), which, as [4] explains, already hold 40% of the world’s cropland.

Ref. [41] describes various scenarios (illustrating the use of disused land within the city as well as at the periphery) to show that a city like Cleveland could cover 100% of its food needs. Studies have also been carried out in Europe (Rome, Paris, etc.) to investigate whether various cities could cover their food needs if food started to be approached through a spatial planning lens or as an innovative dimension of territorial policy, progressively generating tighter cooperation amongst stakeholders [46]. This illustrates the fact that the geographical scale covering food activities aimed at contributing to urban transition actually enlarges the boundaries of the city itself to the city-region—a territorially integrated node of socio-spatial architecture to configure rural–urban linkages [47]—and the ‘city-region food system’ [48].

The extended boundaries, as we will see later, also reflect the various urban ecosystem functions that the urban food system contributes to, extending beyond the city centre to the city’s periphery.

3.1.3. Urban Food Security, Food Democracy and Alternative Food Networks

The concepts of SFSC and CFS emerged in the context of the broader debate on ‘alternative food networks’ (AFNs) [48], which “represent a shift in the role of consumers from passive end-users of food products towards more proactive ‘citizen–consumers’ who intend to regain control over the ways in which their food is produced and provided” [48] (p. 290). AFNs encompass new types of food production processes “in which voluntary, associational principles and participatory forms of self-management are paramount, suggesting the need for a revaluation of the role of civil society-driven governance mechanisms as a source of innovation and transformation of agri-food systems” [49] (p. 291). Even though these initiatives are increasingly emerging at the local level, particularly in industrialised countries, where municipal governments are recasting themselves as food system innovators, their impact at a more global level is also important since they respond to a ‘new geography of food security’ [49] that places localised circular food systems at its core, contributing to the emergence of better global food democracy—a situation in which, as [50] explains, “all members of an agro-food system have an equal and effective opportunity for participating in shaping that system, as well as knowledge about the relevant alternative ways of designing and operating that system” [50] (p. 83).

Ensuring urban food security and the ability of the city and its periphery to provide for the needs of its citizens are key initial motivations in transforming cities into more circular ones, as well as an indicator of its resilience against adverse effects—such as the COVID-19 pandemic, during which food security was jeopardised. Ensuring that a city becomes more resilient thanks to a circular urban food system requires consideration of the geographical scale at which this circularity needs to be implemented, as the previous section explored, and also the temporal scale, as the next section focuses on.

3.2. Reflection on the Temporal Scale of CFS

Finding means of reusing or eliminating waste and by-products in view of promoting circularity in the production of goods and services that meet urban citizens’ needs requires innovative processes, cooperation amongst stakeholders, and new regulations and governance systems that give an overview of the ‘state of improvement’ to be achieved.

Operationalising such a transition is going to require, above all, time.

Thus, for instance, time will be needed for “the learning obtained by key stakeholder engagement in the CD process [to] result in the scaling-up of projects or translation of circular practices and infrastructure to new locations” [11] (p. 32). Temporal considerations are essential when discussing and negotiating the social integration of technical inventions (i.e., innovation) that would help to minimise waste. Whilst EIS for CFS can be enhanced through new forms of urban planning in which innovative forms of development can emerge [11] (p. 27), knowledge sharing regarding such innovations can also take place through broader networks (e.g., the Urban Green Train [34] and the FoodLink [46] projects). As [6] stresses, such networks of learning can facilitate the transformation over time of urban systems, since “the adaptive capacity of a city is underpinned by the potential for the urban community to self-organise and learn and for the socio-technical systems to co-evolve” [6] (p. 4). Such a form of dynamic adaptive governance [51] is designed to allow for and use disturbance to build knowledge so as to increase resilience and the capacity to respond to future uncertainty (such as climate change). It requires the ongoing iterative process of policy monitoring and the involvement of stakeholders in creating these policies through collaboration, including with non-governmental bodies.

In all cases, new temporal dimensions do not only relate to the time needed for stakeholders to learn from each other and for innovations and new practices to be integrated in society; they also reflect the temporal scales at play in ecological processes such as those in agricultural production.

4. Transitioning Towards Sustainable Cities Using Circularity: How and with Whom?

Actions need to be coordinated in a circular city. Transforming cities into circular ones necessarily requires a better understanding of the type of waste that is being generated and by whom, its quantities, and how it could be reused, recycled or given added value. Often, approaches towards circularity are reduced to technical eco-innovations. An input–output/material flow type of overall (albeit quite complex) tool can, for instance, help in reallocating misplaced ‘undesirables’. However, as explained earlier, the objective of transforming a city into a more circular one in view of increasing its resilience and of involving its citizens in its transformation goes beyond this technical ‘redistribution exercise’. This section offers two interconnected means of addressing the question of which types of ‘barometers of circularity’ can be built and who would be using them. The first one is to integrate circularity in the context of the city viewed as an ecosystem. Using circularity as a barometer to facilitate sustainability transitions here therefore means respecting circular regenerative production loops whilst protecting urban ecosystem functions. The second subsection discusses how participatory urban governance processes can use the framework presented above in order to help make FS circular.

4.1. A Systemic ‘Barometer of Circularity’

Here, we suggest representing the city as a social–ecological–economic ecosystem that delivers various types of functions, as opposed to only consumption goods. This approach builds on work on the System of Environmental and Economic Accounts—Experimental Ecosystems Accounts (SEEA-EEA), aimed at improving economic performance whilst protecting ecosystem services [52]. It, however, differs from this in that it does not advocate for the building of ecosystems in parallel to economic accounts but considers the city itself as “an urban ecosystem in which resources are consumed and waste is produced from a myriad of activities” [6] (p. 8). As [28] explains, “through the lens of CE, cities are equated to ecological-economic systems and are related to the metabolic flows of their local economies” [28] (p. 47). Urban activities therefore contribute to delivering and protecting urban ecosystemic functions (UEF)—understood as including production (the provision of raw materials that become food, fuel, etc.), habitat (a liveable place for human communities), regulation (of major cycles—including ecological, such as carbon and water) and amenity (contributing to human welfare) functions [53]. Focusing in such a way on understanding the dynamic interactions between nature and society and on addressing the normative question of how coupled human–environment systems would function aligns with what [16] describes as “post-normal sustainability science”, approaching the city as an “urban metabolism”, i.e., “the sum total of the technical and socioeconomic processes that occur in cities, resulting in growth, production of energy, and elimination of waste” [15] (p. 73). Adopting circular approaches will cause us to “face the key challenge of selecting approaches to urban design and materials and production methods that comply with natural ecosystem laws” [13] (p. 8).

At the city level, this means that a completely new integrated science of urban planning is needed, with decision-making tools that reflect this [54].

Table 1. Goods and services delivered by urban agriculture activities through ecosystem functions (compiled by the author).

Production functions	Food, biomass,…	Provision of local food Increase in food security
Habitat functions	Buildings	New adapted spaces for UA
	Private and public space	Green corridors
	Transport infrastructures/connections	Social & cultural mix/Alternative Food Networks
Information functions	Health services	Biological healthy food
	Education services	Agro-ecological activities as a teaching resource
	Recreation, culture, tourism	Walks and fruit-picking ‘tours’; Improved local image, place branding
	Training for new jobs	Training sessions
	New laws and regulations	Healthy food production
	Legal measures/subsidies/funding	Promotion of land use for UA
Regulation functions Sink functions	CO2 absorption	Growing vegetation absorbs more CO2
	Waste and water recovery/re-use	Waste water re-use for irrigation
	Nutrients recovery and reuse	Re-use to enhance productivity
	Energy recovery and reuse	Energy saved through limited transport
	Building materials recovery/re-use	Building material for parks, greenhouse…
	Building/land recovery	Reconverted land for green corridors
	Compost made with Organic waste	Compost used in large quantity
	Reduction of soil erosion	Increasing soil fertility; carbon storage in soils
Regulation functions Life support functions	Restoring/protecting water cycles	Reed cultivation to absorb floods; Groundwater recharge; storm water retention;
	Regulation of temperature in city	Create shade and cooling
	Biodiversity protection	Varied species planted/enhance pollination, e.g. through urban bee keeping
	Landscape ecology	Green corridors
	Governance of the urban ecosystem’s circularity	New jobs in UA, landscape ecology Facilitators for negotiations and governance

illustrates how we can start approaching the city as an ecosystem by observing how UA activities contribute to all UEF. Building on this, we can now explore in more detail which forms of capital are needed for people to be able to carry out UA activities. These can be on an ecological basis (e.g., water or soil), but forms of capital also include technologies (e.g., hydroponic farms), human capital (with people being trained for new types of jobs in UA), cultural capital (e.g., social learning taking place in allotment gardens and cultural mixes) and financial capital (e.g., potential subventions). Using capital sustainably will equate to paying particular attention to whether the type of capital can be substitutable. Critical natural capital cannot be replaced and, since it is responsible for the delivery of important ecosystem functions, must be protected as much as the functions themselves.

The operationalisation of strong sustainability can therefore be achieved by both maintaining UEF and maintaining the capacity of the capital stock to provide these functions [50], using information such as that provided in

Table 2. The use of capital forms by FS activities to contribute to UE functions (compiled by the author).

Standards Targets, RC Restrictions on Capital Use	Type of Capital C Needed in Food System Activities	FSA1 Production	FSA2 Distribution	FSA3 Processing	FSA4 Education	FSA5 Food Waste Managt	Total Capital Use for UEF 1	FSA1 Production	FSA2 Distribution	FSA3 Processing	FSA4 Education	FSA5 Food Waste managt	Total Capital Use for UEF 2	FSA1 Production	FSA2 Distribution	FSA3 Processing	FSA4 Education	FSA5 Food Waste Managt	Total Capital Use for UEF 3	FSA1 Production	FSA2 Distribution	FSA3 Processing	FSA4 Education	FSA5 Food Waste Managt	Total Capital Use for UEF 4	Total Type of Capital Used TCn in the LMA Food System Activities to Contribute to Urban Eco-Systems Functions
RC1	C1 water						tC1 UEF1						tC1 UEF2						tC1 UEF3						tC1 UEF4	TC1 = sum of tC1 UEF1,2,3,4
RC2	C2 seeds						tC2 UEF1						tC2 UEF2						tC2 UEF3						tC2 UEF4	TC2 = sum of tC1 UEF1,2,3,4
RC3	C3 soil						tC3 UEF1						tC3 UEF2						tC3 UEF3						tC3 UEF4	TC3 = sum of tC1 UEF1,2,3,4
RC4	C4 compost						tC4 UEF1						tC4 UEF2						tC4 UEF3						tC4 UEF4	TC4 = sum of tC1 UEF1,2,3,4
RC5	C5 usable waste						tC5 UEF1						tC5 UEF2						tC5 UEF3						tC5 UEF4	TC5 = sum of tC1 UEF1,2,3,4
RC6	C6 land Tenure						tC6 UEF1						tC6 UEF2						tC6 UEF3						tC6 UEF4	TC6 = sum of tC1 UEF1,2,3,4
RC7	C7 new Laws						tC7 UEF1						tC7 UEF2						tC7 UEF3						tC7 UEF4	TC7 = sum of tC1 UEF1,2,3,4
RC8	C8 Funds						tC8 UEF1						tC8 UEF2						tC8 UEF3						tC8 UEF4	TC8 = sum of tC1 UEF1,2,3,4
RC9	C9 staff						tC9 UEF1						tC9 UEF2						tC9 UEF3						tC9 UEF4	TC9 = sum of tC1 UEF1,2,3,4
RC 10	C10 energy						tC10 UEF1						tC10 UEF2						tC10 UEF3						tC10 UEF4	TC10 = sum of tC1 UEF1,2,3,4
by-products
waste
Products & Services
UE Functions		Production functions					total	Habitat functions					total	Regulation functions					total	Amenity functions					total
Restrictions Urban Ecosyst functions REF		RE Production F						RE Habitat F						RE regulation F						RE Amenity F

.

Table 2 describes how various forms of capital (listed in the second column as C1 water; C2 seeds, etc.) are used in food system activities (e.g., ‘FSA1’: production; ‘FSA2’: distribution, etc., in the top row). The different activities within the food system themselves contribute to the urban ecosystem functions (bottom row) of production, habitat, regulation and amenity. Whilst FSAs generate products and services, they also create by-products and waste (see the three rows above the UEF row). Reusing these will be of concern when making cities more circular. Table 2 is somewhat inspired by the input–output tables built by those working on ecosystems accounts. It can be used as a barometer to illustrate, over a period of time, how much capital (of various types) is being used, to contribute to the creation of particular goods and services, hence also contributing to the overall urban ecosystem functions, but potentially generating waste.

Table 2 also highlights the existence of restrictions both in relation to UEF and to the forms of capital use. If EC targets have focused on halting the loss of biodiversity and the degradation of ecosystem services, as explained in the EU Biodiversity Strategy 2020, other imperatives are being mentioned. In particular, city planners have been called upon to take immediate action to address the actual ecological overshoot (i.e., the conversion of renewable resources into waste faster than waste can be transformed back into resources)—such as finding sustainable alternatives for land use and means of improving soil regeneration and biodiversity—in order to transition cities towards circular economies and metabolisms [24].

Figure 1 illustrates this in a less numerical way, showing how various forms of capital are used in FS activities, allowing them to contribute to various urban ecosystem functions and hence delivering goods and services (such as those described in Table 1) but also potentially waste and by-products. A circular city would have zero waste and by-products, and achieving a circular city requires us to pay attention to protecting its ecosystem functions. A similar diagrammatic representation could be generated for other types of urban activities, but, interestingly, FS activities present the advantage of contributing to all UEF. They are therefore particularly useful in contributing to protecting these functions, hence not only reducing waste but also regenerating the health of the city as a ‘metabolism’.

A number of guiding principles, new regulations and ecological and health standards have been identified.

Table 3. Restrictions on capital use, protecting EF and the creation of by-products and waste (compiled by the author).

Capital C		Standards, Targets, Restrictions on Capital Use (RC)				TCn	Standards, Targets, Restrictions on Food System Activities
C1 water	RC1	% of water reuse % of water saved by using agroecological processes or others				TC1	FSA1 Production Encourage local food production, food security and minimum imports
C2 seeds	RC2	Sustainable provision of seeds Seed bank				TC2
C3 soil	RC3	% of soil regenerated % of top soil created				TC3	FSA2 Distribution Minimize transport and shorten distance for food supply chain
C4 compost	RC4	% of compost used No chemical fertilisers				TC4
C5 org waste	RC5	% of waste composted, reused % of waste transformed into energy				TC5	FSA3 Processing Add value to waste through innovative processes
C6 land Tenure	RC6	% of waste land reused/rehabilitated Efficiency in land-use; crop rotation; permaculture principles…				TC6
C7 new Laws	RC7	New laws for green infrastructure and corridors New laws about urban agriculture, local production, healthier food				TC7	FSA4 Education Create better awareness concerning food production, ecological and human health, food and identity/cultural heritage, agroecological practices…
C8 Funds	RC8	Funds generated by adding value to waste Number of Circular projects funded by local authorities				TC8
C9 staff	RC9	Decrease in unemployment due to new jobs for Circular City % of training on innovative activities for CE leading to a job				TC9	FSA5 Food waste management Reduce food waste, redistribute
C10 energy	RC 10	% of renewable energy used % energy saved thanks to reduced transport (short supply chain)				TC10
by-products		% of by-product reused Waste management cost				Protect critical natural capital	Cost saving thanks to circular processes Value added to waste
waste		If waste NOT immediately reusable: reflection on innovative processes to reuse them or to create product differently					Innovation encouraged through education, funding, new laws; reallocation of waste into new processes
Products & Services		Meet Production needs		Meet Habitat needs		Meet Regulation needs			Meet Amenity needs
Urban Ecosyst. Functions UEFs		Production functions	total	Habitat functions	total	Regulation functions		total	Amenity functions	total
Restrictions UEFs: RE		RE Production F		RE Habitat F		RE regulation F			RE Amenity F
		Optimise sustainable yield Respect minimum standards and renewability rates		Respect minimum critical ecosystems’ size		Max. carrying capacity Protect biodiversity Ensure ecological regeneration			Human health standards Social cohesion Valuable landscpae

relates these to the UEF and the forms of capital contributing to them.

This framework can serve as a basis in checking that needs are being met whilst also protecting the UEF and various forms of capital. (A fuller presentation of this framework, intended to be an aid to decision-making in an urban setting, is presented in [55] Using a systemic approach, it is intended to help urban planners to find means of strengthening the relations among actions, actors, spaces and resources in order to regenerate and improve exchanges between different areas of the cities, by taking a closer look at the overall metabolism of the urban FS.

4.2. A Participatory Approach to ‘Urban Circularity Governance’

We can now explore in more depth the necessary participatory dimension in circularity transitions and how such new governance will involve stakeholders of the urban FS. Transitioning a city towards circularity is a complex process that requires various iterations—through ‘developmental evaluations’ that provide feedback, generate learning and are adapted to the reality of each context. Such a participatory process can therefore encourage both the identification of circularity potential and clarify the vision of the type of circular FS that the community seeks to achieve [56]. The authors of [19], in their Re-Design Project of Organic Waste in Porta Palazzo Market in Turin, Italy (RePoP), showed that it is only thanks to a participatory, collaborative, inclusive and diversified governance process that a transition to a regenerative type of CE could be achieved.

4.2.1. Integrating Our Ecosystemic Framework into Urban Planning—How?

Ref. [11] concluded that “A regulatory and policy framework is essential for transforming urban systems: spatial and land-use planning could provide the arena for innovative CD at a city scale” [11] (p. 18). However, it also warns that conflicts between planning regulations and CD goals may also exist. For example, whilst standards for soil decontamination (imposed by planning) may stop brownfield sites from being reused, the adoption of other planning standards in favour of circular solutions might encourage bioremediation—allowing the immediate reuse of the site. When the regulatory framework reinforces the prioritisation of circular goals, circular transformations are therefore more likely. Whilst [57] denounced the fact that food production and security was a stranger to the urban planning field, the situation has changed in the last twenty years, and European and national measures are being encouraged to both produce food differently and to make cities more sustainable. This context seems ideal in both providing practical examples from which to scale up circular transformations and to change perceptions of urban governance and ‘success’.

If urban planning could be subjected to the reforms that are being currently being encouraged, it could focus on the creation of circularity as its main strategy. ‘Strategic urban planning’ would then need to be ‘tailored’ to circularity, since the latter constitutes a ‘moving target’. As [57] explains, transitioning towards “urban resilience refers to the ability of an urban system and all its constituent socio-ecological and socio-technical networks to maintain or rapidly return to desired functions in the face of a disturbance, to adapt to change and quickly transform systems that limit current or future adaptive capacity” [57] (p. 39). Various developmental options need to be envisaged to meet people’s needs whilst protecting UEF and the capital upon which they depend.

In order to allow for the planning flexibility that CD requires, Ref. [53] advocates for the use of “performance-based planning”—in which the plan (which defines long-term goals and strategies) does not indicate how to pursue the outcomes but identifies the performance criteria against which actions should be assessed (RC, FSA and RE indicators in Table 3).

Performance-based approaches continuously accommodate the new innovations emerging to address the need to reuse waste and by-products, which makes them a suitable way to promote approaches linking ecosystem services and various decision-making processes [58]. Performance-based planning could therefore work with our urban ecosystemic framework, aiming at achieving urban transformation that meets certain performance criteria—such as minimum standards, renewability thresholds, etc. Whilst some of these levels can be identified scientifically, and sometimes specified in new European or national regulatory frameworks, some others (e.g., the percentage of wastewater to be reused in UA) have to be negotiated and aligned with innovative processes that can help to close ‘urban circular loops’.

Practical examples of circular FS, including bottom-up approaches, have a role to play in this governance system, whose aim is to develop an implementation plan for circular strategies that is reviewed on a regular basis. Stakeholders’ participation therefore continuously refine RCs and FSAs. Figure 2 illustrates how the targets, standards and objectives are assigned to the various types of capital being used, the different activities in the food system, the urban ecosystem functions and the waste and by-products themselves. The urban circular transformation discussed here is therefore connected to an FS that, geographically, extends to the periphery of the city.

The UFS can, for instance, be reorganised into refuse (to use unsustainable energy and materials), rethink (redesign FS towards regeneration), reduce (increase efficiency), reuse (design for extended use), refill (design refillable packages), regift (facilitate second-hand), recycle, rot (turn food into compost) and repeat (the nine Rs) activities, which [59] describes as the most applicable for urban FS to realise circularity.

4.2.2. A Collaborative Tool for the Implementation of a Food Systems Circular Strategy

The circularity of cities calls for reformed governance where stakeholders become better connected and interdependent through more collaborative planning processes [11]. The objective of such ‘social innovation’ is to build the capacity (expertise, skills and supply chains) among infrastructure and service providers to deliver circular systems of provision in cities—allowing, for instance, construction companies and service providers to design an integrated, closed-loop waste-to-energy system, using learning workshops, direct access to local planners and regular multi-stakeholder workshops to promote innovation. Such participation of stakeholders can be achieved in various ways. The ‘Re-Food’ movement (https://re-food.org/en/home—accessed on 17 March 2025) is a good example of the potential for success in working together through volunteering and humanitarian support to decrease the food wastage footprint. The Horizon 2020 project ‘Cities: cooperating for a CE’ also led to the creation of an online network that helped to manage information about surpluses of meals and food, food donors involved, charity institutions and other stakeholders. These relate to the COST network on urban allotment gardens in European cities and to the Milan Urban Food Policy Act (2015) on sustainable food systems. As [60] explains, both bottom-up and top-down approaches can work individually in transitioning towards a circular food system. However, the scaling up of circular approaches at the city-region level will only happen through collaboration between these types of initiatives.

The framework proposed in this article values participatory governance through the negotiated identification of various targets, standards and objectives to work towards when trying to make the urban food system more circular.

Figure 1 and Figure 2 offer a schematic representation of the steps taken in this transformative process. The objective is to assist urban systems in identifying their circularity potential and use it to develop an implementation plan for regenerative strategies that will ‘repair’ urban ecosystem functions.

In the first instance (Figure 1), efforts are focused on understanding how capital is used to perform food system activities and how these activities contribute to all urban ecosystem functions (see Table 1). Stakeholders from the various types of activities in the food system (production, distribution, processing, education and waste management) then identify the goods and services, as well as the waste and by-products, that have been created. In the second step, the collective description of the vision to be achieved by negotiating various performance criteria (Figure 2) is carried out. The result of the strategy is ‘tested’ through the iterative use of Steps 1 and 2 (Figure 1 and Figure 2).

The regenerative objective lies in organising our food production in a way that rebuilds the ecosystem functions performed by the ‘urban metabolism’. Unusable waste needs to be reduced for ecosystem functions to be protected and to ‘perform’. In parallel, a strong focus needs to be placed on how urban ecosystem functions can help in reducing all forms of wastes, i.e., not only waste being generated by food activities but also ‘wastescapes’, wasted knowledge, etc. (see Section 3). Thus, for instance, the greening of a city through the growing of food enables CO₂ capture as well as, potentially, a more efficient water system, addressing flood management depending on which crops are being used. The wastes being addressed here are both pollution (CO₂) and wastewater.

If the urban metabolism is improved thanks to enhanced urban ecosystem functions, the resilience of the city is enhanced as a result of it being more circularly managed.

5. Conclusions

This article critically assessed various dimensions of ‘circularity’ principles and focused on the illustrative example of circular urban food systems.

First, the article showed that the geographical and institutional contextualisation of ‘circularity’ can trigger a reflection on what we mean by circularity and why we see it as desirable. Here, we examined circularity in terms of identifying how it can contribute to transforming cities into more sustainable and resilient ones, i.e., one of the priorities for the 21st century. This part showed that we need both a practical starting point to grasp the notion of ‘sustainable city’ and a better understanding of how a circular city can lead to a sustainable one. The practical example that we used was the urban food system, since food security has been identified as key to urban resilience. This article therefore shows the links between circularity, sustainability and resilience and suggests a paradigmatic readjustment away from the circular economy, technical industrial ecology and new business models in order to prioritise the notions of regenerative, circular development and the protection of UEF.

In the second part, the illustrative example of food systems helped to discuss the geographical and temporal scale at which urban circularity ought to take place. Taking urban resilience and food security as the main objectives in urban transitions, we highlighted the need for both drawing a metropolitan boundary, extending the urban to a new geographical scale that includes the peri-urban as a particularly important zone to regenerate, and the broadening of the community of stakeholders involved when it comes to sharing knowledge on UA’s best practices and promoting new global food democracy systems. This requires a new economic paradigm and decision-making process in favour of cooperation and inclusive governance that can facilitate iterative negotiation.

The third part concluded by presenting an aid to decision-making, intended to support such governance, based on the regenerative approaches advocated for in the first part, at the scales presented in the second. Such a platform illustrates a framework from which the barometers of circularity can be derived, based both on meeting people’s needs and on protecting urban ecosystemic functions. This part therefore approaches the question of who can operationalise circularity and how.

The objective of this article was to show that making cities more sustainable could be ‘kickstarted’ by making urban food systems circular: this could generate a transformational, domino effect, interconnecting the various urban ecosystemic functions, as well as stakeholders linked to urban food production.

This framework is applicable to European and non-European settings and promotes the sharing of best practices and iterative learning on how to improve the performance criteria used to guide actions. What is less transferable, and therefore more context-dependent, is the way in which a participatory governance process can be facilitated. Ultimately, because the framework presented here both looks at urban activities as ‘feeding’ urban ecosystem functions and suggests that a circular UFS could boost the rebalancing of these UEF overall, this paper calls for the radical transformation of urban planning if it is to promote the creation of resilient and circular cities that are more food-secure.