Planning a ‘sustainable city’ with hinterlands: The case of Yokohama City,Japan and its soft space planning to reach net-zero

The geographical scale of the urban

Across urban studies and practices in the last half-century, the emphasis has been put on the internal conditions of cities (Angelo and Wachsmuth, 2015; Brenner and Katsikis, 2013, 2020). While recent works, especially by Brenner, question these narrowly focused views on cities, Lefebvre conceptualised such a critical viewpoint earlier and was influential in motivating those urban researchers. Lefebvre understood the urban not as a type of society in a particular space where infrastructure, investment and population concentrate but rather as an urbanisation process of spatial organisation and territorial differentiation (Brenner, 2004; Brenner and Katsikis, 2013). Based on this understanding, he hypothesised that ‘society has been completely urbanized’ (Lefebvre, 1970/2003: 1) because the urban as a process would impact all areas of the planet. Furthermore, these changes at a planetary scale would, in turn, shape all the landscapes taking part in the urbanisation processes, both within and beyond the centre of agglomeration (Lefebvre, 1970/2003). Such an idea enables the interpretation of urbanisation as a process that intensifies and consolidates interdependencies between city and non-city. A city may be the centre of attention in the investigation of urbanisation, but the geographies related to a city also start to matter (McFarlane, 2020).

Building upon this proposition and alongside the theorisation of planetary urbanisation (Brenner and Schmid, 2015), Brenner and Katsikis (2020) engage with the spaces beyond cities and their role in urbanisation processes. To call these spaces, Brenner and Katsikis use the term hinterlands: the spaces that are incorporated into urbanisation as operational landscapes used for the production of food, water and energy, resource extraction and environmental management, among others (Brenner and Katsikis, 2020). Informed also by the investigations on urbanisation with metabolic approaches (see, e.g., Cronon, 1991), Brenner and Katsikis focused on these ecological functions that hinterlands play in relation to cities and described urbanisation as a socio-metabolic process (Brenner and Katsikis, 2020), where hinterlands support cities by supplying metabolic inputs (e.g., labour, materials and food) and absorbing metabolic by-products (e.g., pollution and waste). Based on their understanding, ‘city development is supported by, and actively coevolves with, hinterland spaces’ (Brenner and Katsikis, 2020: 25), and hinterland spaces should not be ignored in the study of cities. In this sense, this metabolic approach underscores the connections between cities and hinterlands and is a contributor to counter the city-centric conversation in urban studies.

The metabolic inputs and outputs, specifically of cities, have been interrogated in the study of urban metabolism. Urban metabolism refers to the total of the socio-technical and socio-ecological processes that occur in cities to sustain the inhabitants’ lives, resulting in the consumption of materials, labour, energy and water and the elimination of waste (Bahers et al., 2020; Brenner and Katsikis, 2020; Kennedy et al., 2007; Kennedy and Hoornweg, 2012; Wolman, 1965). Research on urban metabolism primarily aims to quantify these flows of inputs and outputs (e.g., Billen et al., 2012; González et al., 2013; Rosales Carreón and Worrell, 2018), which reveal the cities’ spatial spread over the surrounding areas (Tanguy et al., 2020) – or what Brenner and Katsikis call and this paper refers to as hinterlands. Such understandings of links between cities and other territories demonstrate the reality behind cities’ existence and are fundamental to understanding their sustainability – that it cannot be achieved independently.

Nevertheless, few studies focus on how such city–hinterland metabolic links play out in the process of planning for sustainability. Although quantifying resource flows may effectively inform urban sustainability policies by showing the impacts cities have on spaces beyond their bounded territories, they are not comprehensive enough to contextualise how the planning for sustainability could be negotiated based on those metabolic relationships. Being aware of this unattended area of research, Bahers et al. (2020) analyse the city–hinterland metabolic flows of energy in a French port city while examining the power dynamics attached to these relationships. The study observes the presence not only of synergies and cooperation but also of conflicts between these territories. There exists ‘the control of rural resources by urban infrastructures’ (Bahers et al., 2020: 7), and the authors suggest how the recognition of such power relations is vital for a vision towards sustainable and just metabolic relationships (see also John et al., 2019). By utilising these conclusions, this paper would like to take a step further and analyse a case that facilitates city–hinterland metabolic links and discuss how power affects the arrangements and delivery of sustainability initiatives.

Essentially, this research aims to investigate how the urban sustainability concept is applied with its wider-scale interpretation and how such an application influences a city's relationships with the hinterlands. Given the tendency of urban studies to focus on conditions within city boundaries and urban metabolism studies on the measurement of metabolic relations, the research attempts to overcome these gaps by shedding light on the hinterlands and what their metabolic connections to cities mean for the making of urban sustainability.

Soft spaces of planning for urban sustainability

In an attempt to explore cities’ sustainability initiatives concerning the metabolic links between cities and hinterlands, this research looks at urban metabolism through the lens of ‘soft spaces’. If city governments were to take actions based on the understanding of the hinterlands’ roles in sustaining urban metabolism, there would be a need to strategise and plan beyond traditional administrative boundaries. This need for rescaling coincides with what planning with ‘soft spaces’ attempts, which essentially is to rescale strategic spatial planning.

‘Soft spaces’ is a concept used mainly in academic planning debate and was introduced by Haughton and Allmendinger to refer to non-statutory, informal scales that tactically use fuzzy boundaries (Haughton and Allmendinger, 2008: 143). Although planning practices at such scales had been observed prior to the introduction of this concept, Haughton and Allmendinger put their observations in the context of British spatial planning to use by defining them. The concept of soft spaces has since evolved and also integrated into other countries’ situations, especially in Europe (Haughton et al., 2010; Kaczmarek, 2018; Olesen, 2017; Olesen and Hansen, 2020; Purkarthofer and Granqvist, 2021; Stead, 2014) and the current understanding of the concept could be explained using other terms such as city-region or cross-border collaborations (Haughton et al., 2010). These identifications of soft spaces reflected the growing desire among policymakers to depart from, as opposed to soft spaces, hard spaces that are bounded by formal and statutory political or administrative boundaries. They are characterised by delays, bureaucratic complexities and limitations to reflect the ‘real geographies’ of problems or potentials, whereas soft spaces are flexible owing to their fuzziness (Allmendinger and Haughton, 2009; Haughton et al., 2013; Haughton and Allmendinger, 2008; Olesen and Hansen, 2020; Purkarthofer, 2018; Zimmerbauer and Paasi, 2020).

In fact, the initially studied Thames Gateway regeneration project in the UK, where the area bridging multiple local authorities was formally recognised as one of the national growth areas in 2003 (Allmendinger and Haughton, 2009; Haughton et al., 2010), was tightly linked to the country's political interest to move away from hard spaces. As the national government was demanding coordinated planning that delivered visible outcomes quickly without significant reforms, Thames Gateway became its interest in delivering strategic action and cooperation beyond the local level (Haughton and Allmendinger, 2015; Purkarthofer and Granqvist, 2021). A similar case where the planning of soft spaces is linked to the interest of national governments has been observed elsewhere (e.g., Galland, 2012).

Based on the similarity between urban metabolism and soft space ideas to enable the rescaling of urban policies, the soft spaces approach in planning can be considered as a potential tool to implement urban metabolism ideas in practice. However, planning of soft spaces has been observed to prioritise economic growth agenda over social justice or environmental goals (Galland, 2012; Waite and Bristow, 2019; Zimmerbauer and Paasi, 2020). Although there is greater recognition of the potential to have multiple agenda in operating soft spaces (Morgan, 2014; Waite and Bristow, 2019), how rationales other than competitiveness emerge and persist has not been interrogated thoroughly. The questions this paper asks will address one of these overlooked perspectives in soft space studies: sustainability, especially from the environmental point of view.

That said, this research still draws insights from studies examining economic competition-oriented soft spaces, particularly the work dealing with how multiple governments reach an agreement over strategies and plans. Notably, Granqvist et al. (2021) question the assumption of a smooth transition to city-regional administrative arrangements and observe the strategic spatial planning of a city-region to test this presumption. Their study notes that city-regional ‘soft’ programmes do not replace but layer onto the existing ‘hard’ institutional framework of local government and statutory land-use planning. Such layering could be a deliberate choice to integrate city-regional strategic planning with statutory local master planning. This way, the region could have the ‘best of both worlds’ (Granqvist et al., 2021: 853) by expressing the city-region's overarching visions focused on a particular demand without disturbing the conventional legally binding plans paying equal attention to all land use matters. With particular attention given to such a multiplicity of spaces, Zimmerbauer and Paasi (2020) argue that borders become porous rather than softening due to the persistence of clear-cut borders and hard spaces. The traditional borders can continue ‘“haunting” and affecting in quite material ways what can and cannot be done in practice’ (Zimmerbauer and Paasi, 2020: 785) in the newly enacted soft spaces, leading to the hardening of them. These observations can inform this paper's case study by providing perspectives to analyse the local government's motivations and circumstances behind the implementation of soft space planning and its relation to hard spaces.

It is also essential to visit the role of power in soft space planning. As mentioned briefly using the work of Allmendinger and Haughton (2009) and Galland (2012), planning with soft spaces is considered to be brought by a political process which is power-laden (Mattila and Heinilä, 2022). Enacting of soft spaces calls a specific scale into being, which is a result of political struggle and foregrounds the power relations of the actors involved (Davoudi and Brooks, 2021; Mattila and Heinilä, 2022; Zimmerbauer and Paasi, 2020). Additionally, this process often utilises storytelling in order to conceive such space that is not legitimised based on statutory processes, and power counts in creating and disseminating certain narratives that reproduce power relations (Mäntysalo et al., 2020; Olesen, 2017; Purkarthofer, 2018). As power relations between cities and hinterlands are observed in urban metabolism analysis by Bahers et al. (2020), these studies offer another essential perspective to consider how power plays out in the negotiation process to form sustainability-oriented soft spaces.

Expanding the geographical scale of urban sustainability

Evidence suggests that the Yokohama city's interpretation of urban sustainability with the recognition of the areas outside their administrative borders can be traced back to the country-wide experience related to electricity use, which fostered an awareness of the cities’ impact on the hinterlands’ conditions. As a civil servant from Yokohama city put it:

In 2011, the Great East Japan Earthquake happened, and there were many power outages. At that time, what we saw [happening in the areas hit by the earthquake] was that … even after the power stations there started working, the electricity was still unavailable. Where was the electricity going? It was going to urban areas, and that was the set structure. In short, the city is built on electricity from the rural areas, but the rural areas don’t benefit from it, and this was seen as a problem. I think, at that time, people became very conscious of the idea to make a win-win relationship between the two sides, rather than [rural areas] being just the supplier. (Interview 4, Yokohama city)

This perception resonates with various writings documenting how the disaster exposed the structure where the capital region, Yokohama city included, ‘imposes’ (Nakamura, 2012: 55) the supply of its metabolic inputs to the north-eastern, rural parts of the country where the earthquake hit and how this structure needs to change because it makes the rural deal with the pollution or take on the risks associated with the proximity to power plants, and does not allow them to develop autonomous controls of their economy (e.g., Nakamura, 2012; Nakamura, 2011). Such sentiments that are evident in the words of the interviewee and comparable literature start to reveal a sense of momentum prior to the initial idea of a collaboration initiative to reconsider where goods and services consumed in cities come from and how cities impact those areas. The emphasis these statements put on the lack of benefit brought to hinterlands by the urban metabolism system is indicative of a sense of guilt felt by actors in major cities and of hope to make amends by making the energy system not intrusive but beneficial for supplying hinterlands.

Coinciding this momentum was the reconsideration of national energy policies following the event of a disaster. The revised policies promoted the use of renewable energy and the decentralisation of the energy system, and the sub-national tiers of government accordingly needed to review their policies (City of Yokohama, 2014). Consequently, and in parallel to the strategy-making following the worldwide trend to decarbonise, Yokohama city began to strategise how to increase the share of renewably sourced electricity use within the city (City of Yokohama, 2014). In this process, the city turned to the hinterlands as it was intuitively obvious it needed to rely on them (Interview 4, Yokohama city). As these events suggest, the initial recognition of cities’ links to hinterlands through the consumption of electricity post-disaster was joined by the discussion towards the transition to renewables. It was against this background that the collaboration with the hinterlands started to materialise in the 2018 version of the Yokohama City Action Plan for Global Warming Countermeasures (City of Yokohama, 2018), which essentially interprets urban environmental sustainability with an expanded spatial focus on the matter of electricity use. Put differently, from the standpoint of urban areas like Yokohama city, the large-scale natural disaster and subsequent policy shifts cultivated a moral necessity and practical need to incorporate the hinterlands’ perspectives in updating the system sustaining the city's lives.

Although the interview hints that one of the motivations behind this initiative is to create a spatially just system, this aspect is less immediately apparent. In articulating the reasons for collaborations, the practical need from the city's perspective has almost solely been highlighted. After signing the agreements with the first group of partner municipalities and launching the initiative, the city published the estimate that the capacity of renewable energy production equipment within the city only covers 8% of the projected electricity demand (Yokohama City Strategy on the Use of Renewable Energy: 5). This figure is repeatedly utilised in the template official explanation of this initiative (e.g., Yokohama City Action Plan for Global Warming Countermeasures: 61; City of Yokohama, n.d.-b), whereas the sociological factors leading up to it are not mentioned. This observation suggests that the current arrangement owes to the ability of numerical evidence to showcase the supposedly objective rationality for Yokohama city to collaborate. That said, as is evident from the chronology, the need to rely on the hinterlands was not newly acknowledged based on scientific calculations.

Even without doing the calculations, you have a sense that, well, urban areas are generally in a tough situation, right? I think we’ve got a good grasp of that, numerically, in this estimation. (Interview 4, Yokohama city)

Instead, the scientific background supporting this initiative was instrumental in clarifying and solidifying its rationality. In policy-making processes, such ‘facts’ supporting particular arguments play a critical role by manifesting scientific objectivity, which policymakers would want to claim to have based their work on (Richardson, 1996).

However, as the theory of truth and power by Foucault proposes, truth is not entirely objective. It is socially produced depending on how the scientific discourse is carried out and who produces it (Richardson, 1996). Drawing from this understanding, the ‘fact’ is not free from the power exercised by Yokohama city. The number reinforces the city's decision to widen the geographical scale of sustainability initiatives and strengthen a storyline about the city's collaboration with other municipalities, which is a decision required to meet its electricity demand with renewable sources of energy, which is essential to actualise the city's vision: Zero Carbon Yokohama (City of Yokohama, n.d.-b). Added to this narrative is the CES concept (e.g., Yokohama City Action Plan for Global Warming Countermeasures: 61; City of Yokohama, n.d.-b). As an interviewee admits, the concept is used as a keyword to explain this initiative because the basic idea matches, not because the initiative was designed from the beginning to become its model (Interview 4, Yokohama city). As such, the city constructed a storyline using multiple devices, and this story communicates the legitimacy of this collaboration that creates soft space – a space that generally lacks legitimacy due to the absence of an institutional framework, political accountability and participatory planning processes (Purkarthofer, 2018).

The role of administrative agreements in arranging the initiative

Based on the recognition of the roles played by the spaces beyond its boundaries, Yokohama city sought to collaborate with municipalities that were geographically close enough to transfer electricity and had a high potential to produce renewable energy. Various municipalities in the north-eastern part of the country fit the criteria (Interview 4, Yokohama city). By collaborating with them, the city created a new scale optimal to further its renewable energy strategy that could not be fully addressed independently.

However, a civil servant from a partner municipality questioned the role of municipal governments and the municipal agreement because the actual contracts to supply and consume electricity are signed between private stakeholders.

I wonder why we have this agreement when we are talking about the private sector to private sector contract. It's not quite clear where the two municipalities stand. … For us, because the contracts are made between private firms, to whom < the power plant > sells, or < the electricity wholesale > sells, whether they sell to Yokohama or to someone else, it is not something we can interfere with. That is why we didn’t object to the collaboration initiative, and Yokohama city says they were grateful for that. That's this strange relationship we have. (Interview 2, partner municipality) ²

This comment suggests the public authority's understanding not to interfere with the private companies’ decision-making. Thus, it remains vague as to what municipal governments, who have been the responsible decision-makers in the traditional planning processes, are supposed to do; hence, the question of the municipalities’ role and the need for the agreement. On the contrary, a Yokohama city civil servant explains that the agreements between municipal governments add validity to this initiative and provide an overall framework to explain what is taking place (Interview 4, Yokohama city).

By having such an agreement, for example, businesses in the city can say that they are using renewable energy based on the agreement. In that sense, I think it is important to have an agreement in place. There is an idea that the private sector can do this without it, but I think it is important to make it visible in the form of an agreement. The agreement shows what we’re doing in a way that the suppliers of renewable energy can also see it, right? (Interview 4, Yokohama city)

As this remark indicates, the agreement between two municipalities is recognised as an instrument to show support from the powerful actor, the local governments, to draw private sector stakeholders into the initiative and encourage them to supply/consume the RE-sourced electricity. The administrative agreements, therefore, play a role in conveying the envisioned meaning of the enacted space (Westerink et al., 2013) and, accordingly, communicate the significance of the stakeholders to be involved. As an actor initiating this collaboration, it can be assumed that Yokohama city better recognises and has more room to take advantage of such a role played by municipal agreements compared to the partner governments.

Strategic planning and decision-making among stakeholders

Despite the evidence of a question being raised from partner municipalities’ side on the roles they play, no interviewees described the initiative's launching process to be particularly challenging. In that this collaboration has clear beneficiaries (the city to get RE-sourced electricity and hinterlands to earn money), the disincentive of creating spillover that is considered to discourage a municipality or a region from acting (Haga and Ishida, 2022) appears to be minimised. This factor may have contributed to the smooth processes up to signing an agreement. At the same time, this emergence of soft space is based on an informal and non-binding agreement demonstrating that the participating municipalities ‘share a philosophy, and nothing is bound by it’ (Interview 4, Yokohama city). This agreement does not intend to make major changes, such as the formation of new governance structures. The decisions related to the actual operations are shaped by consultations between and among the stakeholders ranging from Yokohama city government, a partner municipal government, companies operating local power plants, electricity wholesale and consumers. ³ This unnecessity of reforms may have been another reason for the smoothness of the process.

On the other hand, the non-legally binding consensus-seeking mechanism hinders the initiative's capacity to deliver the desired outcomes.

It depends on how the partner municipalities think and what the operators who generate electricity there think, and then there's about the locals’ support, and everything is up to these factors. I think we will try to approach them, but it is difficult to talk about doing anything beyond that. … Some municipalities … want to develop their area using the profits gained by selling the surplus electricity to cities, so I think we would be trying to collaborate with local authorities with that kind of idea. (Interview 4, Yokohama city)

These statements point out that the scope of the city's strategy-making is limited concerning this initiative. The city government cannot decide freely based on its area's interests, and it is questionable whether the initiative can be designed for the city to have more significant influence. The initiative respects the partner municipalities’ autonomy and private sector independence. In other words, it does not interfere with the rigidity of non-fuzzy territorial and sectoral borders. Especially focusing on the aspect of territorial borders and autonomy assigned to bordered territories, what this analysis brings is the impossible choice between legitimate rigidity and illegitimate flexibility (Mäntysalo, 2013). In the case of Yokohama city, legitimate rigidity is fully respected when imposing illegitimate flexibility, and consequently, it is uncertain what this illegitimate arrangement could do. As if to reflect this uncertainty, the city does not set numerical goals for how much electricity demand in the city should be covered via the initiative (Interview 4, Yokohama city). The initiative is part of a strategy for the city to utilise renewable energy (Yokohama City Strategy on the Use of Renewable Energy: 21) and achieve net-zero (Yokohama City Action Plan for Global Warming Countermeasures: 45). However, there is more than one way to access electricity from renewable energy (Interview 4, Yokohama city) and similarly to reach the net-zero target. For example, there are arguments suggesting that demand reduction is essential to achieve net-zero (Oshiro et al., 2021), or that the ‘degrowth’ paradigm is one of the paths towards sustainability (Saito et al., 2019). The city–hinterland collaboration measure is not approaching this aspect of the urban sustainability discourse. In this regard, the findings show that the emergence of this soft space is not replacing or intended to replace the existing planning spaces associated with the hard administrative borders. This initiative simply opens up the option of providing clean electricity to the city that the city cannot supply on their own. Such observation echoes the preceding studies capturing how soft spaces become one of the multiple spaces where plannings take place rather than becoming the space (Allmendinger and Haughton, 2009; Zimmerbauer and Paasi, 2020). The soft spaces and fuzzy borders are penumbral – they are in between soft and hard, becoming significant only when the links beyond administrative borders become necessary (Zimmerbauer and Paasi, 2020). The question, on that account, is how the flexible, penumbral space that is one of the scales designed to deal with the issue could actually address the issue. The fundamental rationale behind the emergence of Yokohama city's initiative was to deliver outcomes that the city could not accomplish independently. However, this research suggests that an attempt to deliver using soft spaces, too, has challenges of delivering because it does not surpass the established institutionalised structures.

‘Sustainability’ of the collaboration initiative

Other than the decision-making framework, the capacity to deliver outcomes through this collaboration depends on underlying conditions like political will (Albrechts, 2004; Albrechts and Balducci, 2013; Bryson et al., 2018), and those interviewed reflected this viewpoint. Because the collaboration is not based on a formal contract and is fluid and flexible, they shared concerns regarding the ‘sustainability’ of this initiative itself being jeopardised by political changes.

I don’t know to what extent Yokohama city values our relationship. … I wonder how far this initiative can go, if it is led by municipal governments. (Interview 2, partner municipality)

Especially in the case of partner municipalities, the initiative has not been designed from the onset to fit into their strategies and plans (Interview 2, partner municipality). In other words, when their strategy changes due to the changes in political leadership, the initiative may no longer fit in well, for example, if they want to prioritise local consumption more. No cases of changes in the stakeholders’ attitude or abolishing an agreement, which would most likely mean that the municipalities stop selling the electricity or make efforts to coordinate for the supply scheme, have been observed (Interview 4, Yokohama city). That said, the research finds that the collaboration initiative only loosely ties Yokohama city and partner municipalities and does not guarantee that these connections will stay forever. This aspect of the initiative adds to the complexity of rigidity and flexibility – it has the practicality that illegitimate plans have but does not have the capability that legitimate plans could offer.

Here, this paper would like to draw attention to a missing stakeholder in this initiative: citizens in the partner municipalities. Although they would experience the impact of decisions made, they are not able to express their views through a democratic process. While such a partial separation between planning scales and democratic representations can be welcomed as a positive element of soft space planning by allowing creative policy implementation (Allmendinger and Haughton, 2009; Haughton et al., 2013), this research suggests its risk. As the interview indicates, the lack of direct and explicit support from the public is creating another uncertain factor for the involved actors.

Not related to this renewable energy initiative, but, in other municipalities, the installation of solar power facilities has become a point of contention in the election … and in reality, the decision was that it [building solar power facilities] is not good. (Interview 4, Yokohama city)

The capacity to deliver outcomes is influenced by the strength of political will, and the public influences the political will. In this context, the weak democratic representation in the consensus-seeking stakeholder arrangement could hinder this initiative's sustainability and the delivery of desirable outcomes, not to mention the sharing of benefits between producer and consumer. The last issue will be explored further in the following section.

City, hinterland and power

Due to the fuzziness revolving around this initiative, there is no concrete assurance that this collaboration will lead to a substantial supply of renewably sourced electricity to the extent it contributes to Yokohama city's net-zero goal or continues to provide any impact on the future. However, interviewees do not show doubts about the continuation of this collaboration because; ‘An agreement has been made, and the operators do not seem to change their attitudes’ (Interview 3, partner municipality); ‘It's an agreement that is not that strict and demanding, so … no municipalities have gone that far [to abolish it]’ (Interview 4, Yokohama city); and ‘It's not impossible, but it is difficult to imagine it [pulling out from the collaboration] happening when the initiative is based on a sort of a noble vision of the country’ (Interview 2, partner municipality). Apart from the reason based on the expected long-term validity of the consensus generated and the fuzziness allowing the agreement to exist without taking effect, the remark on ‘a noble vision of the country’ stands out as it suggests this initiative has support from the nationally set agenda. The initiative does not have direct involvement of the national government and does not exhibit national prominence in the way other examples like the Thames Gateway do (Allmendinger and Haughton, 2009). Nonetheless, the national government is encouraging the whole nation to utilise renewable energy as much as possible (Agency for Natural Resources and Energy, 2022), and the concept the Ministry of the Environment promotes, CES, is used in the explanation of this initiative (City of Yokohama, 2021a, 2021b). This subtle influence of national government appears to impact sub-national tiers of government.

There was a question in the council about why we send electricity to Yokohama city. I have been trying to argue or persuade them from various angles. First of all, I say the basic premise is that this is the direction in which the country is heading. In other words, I talk about the CES concept, and I add that there are actual advantages [to < Partner Municipality 1>]. (Interview 2, partner municipality)

What we see is that there is a general consensus to follow what the country as a whole is aiming for, and in this sense, the higher tiers of government have an influence over the lower tiers. This relationship exists for a major city as well; for instance, Yokohama city considers itself to have ‘the duty placed on cities as major consumers of energy’ (Yokohama City Strategy on the Use of Renewable Energy, Forward) to take actions to decarbonise and align with the Paris agreement goal, which showcases the impacts of the national (and international) trend on its vision. This situation could raise a concern if such influence may become a constraint to areas with less power to initiate things – hinterlands in this case. Even if initiatives like this case study start to do more harm than good to the locals in the area (e.g., degrading local landscapes), backing away then would look like the hinterlands are not supporting the ‘noble’ vision. Such conflict of interest that the top-down power relations could impact suggests an invisible yet existing hierarchical decision-making process (Bulkeley and Betsill, 2005; Wolf et al., 2021). In creating soft spaces involving multiple spaces of which the benefits will be felt differently, such structure may fail to respond to one territory's need over the need as a whole.

Power asymmetries between the city and the hinterlands are another power relations identified in this case study. Invoking what Bahers et al. (2020) highlighted about the unbalanced power between them, the interview reveals that the initiative first appeared not to be synergetic but one-sided from the partner municipalities’ points of view.

At first, it felt like we were being dragged along, or we had that kind of passive attitude. (Interview 2, partner municipality)

Such passiveness is indicative of the hinterlands’ understanding that the initiative is Yokohama city's and not theirs. This perception appears to be influenced by how the initiative was set up, which generally started from Yokohama city suggesting an idea to partner municipalities (Interview 2, partner municipality; Interview 4, Yokohama city). In collaborative processes, participation is an arena to exercise power as there is a leading figure in a collaboration whose understanding of the situation determines who participates and who is excluded (Purdy, 2012). When applied to this case study, Yokohama city holds the leadership and invites stakeholders to participate. As such, the city is able to hold power over the hinterlands rather than them being equal partners. Therefore, in this initiative that one city leads and the others join in, the concerns observed in a city-region framework where peripheral municipalities worry that the central city's vision could be imposed upon them and their own interests to be marginalised (Cremer-Schulte, 2014) are similarly experienced. This situation exhibits similarities with the producer–consumer imbalances observed in the case of East Japan Railway (JR East) and its Shinano River hydropower station. The station was built to supply electricity for trains in the Tokyo area. However, it was located in Niigata prefecture, roughly 200 km away from the metropolitan area and disrupted the area's environment by taking too much water from the river. This issue caused a considerable amount of friction among the residents, JR East and municipal governments (which sided with both the residents and JR East) (Tabuchi, 2008, 2010). There was a clear division of areas benefiting and suffering from the hydropower station construction. The issue is resolved for the time being based on the agreement between the local municipality and the company. That said, the process posed a question of how to involve and respect the negatively affected party. Although the main stakeholder in this case is different from the collaboration initiative, it may face a similar situation. Even though the city attempts to make the collaboration beneficial for those hinterland partners, whether it provides actual benefits to the hinterlands has continuously been questioned (Interview 2, partner municipality). In this sense, despite a motivation to re-consider how the city should impact the hinterlands, the power relation endures in this initiative and allows the city to be the dominant influence.

Evidence shows that this city–hinterland's unbalance-ness differs in its degree depending on the situation in the partner municipalities. Under this collaboration initiative, the details ranging from which power plants and wholesale companies get involved to how Yokohama city and the partner municipality collaborate for their area's local vitality are consulted between the city and each municipality on each term. In most cases, from the partner hinterlands’ perspective, they gain opportunities to do events like food fairs at Yokohama city hall (City of Yokohama, 2023b; Happo town, 2023) and access a much larger market than their areas to sell the local products. Case by case, the other benefits differ. For example, one of the arrangements allows the partner municipality to consume the produced RE-sourced electricity locally. Commonly in Japan, all the electricity produced (RE-sourced or fossil fuel sourced) is bought by the nationally designated transmission system operators and distributed by them. This means the areas with power plants are not necessarily getting the electricity produced in their territory, creating the situation after an earthquake described during Interview 4. With the rising interest to utilise RE-sourced electricity in municipalities with access to resources producing them, such as abundant land or wind, local production for local consumption is becoming a desirable condition. The initiative allowed this to happen by inviting a wholesale company willing to distribute the electricity back to the producing area, which counts as a benefit for the hinterlands (see Figure 1 for the detailed arrangement of this case). This way, the motivation to enhance spatial justice seems to be present.

However, some municipalities simply export the electricity produced. In that case, the hinterlands do not directly share the benefits of environmental sustainability, and the social ambition is neglected. The differences among partner municipalities may be due to the municipality-specific context, such as their policy priority or the municipal officers’ capacity. Although more focused studies will be required to confirm such a hypothesis, the current evidence shows how mutually beneficial and synergetic the initiative can be to the hinterlands differs among the participating municipalities.

I, as a person in charge, have gradually come to understand more and more about local revitalisation and renewable energies. My understanding has deepened, and I can see how to utilise this collaboration. Ultimately, in the end, I think it is the capacity of the person in charge that counts. (Interview 2, partner municipality)

Although involving more actors might be a strategy to increase the amount of RE-sourced electricity supplied to the city and thereby secure the initiative's deliverability, municipalities that are yet ill-prepared for such a collaboration could be side-lined or feel like they are.

The interviews also hinted at a potential concern that the hinterlands’ roles might not be adequately recognised. As mentioned above, some hinterlands do not on their own consume the RE-sourced electricity. Because environmental sustainability is what should be achieved globally, where the electricity consumed may not matter. That said, if such contribution does not get recognised, there is limited incentive for hinterlands to produce RE and cities could be dependent on the goodwill of hinterlands. Each municipality in Japan is obligated to report the amount of their CO₂ emissions following a designated calculation method, but under the current method, the lifecycle emissions associated with the production of RE-sourced electricity are not considered (Interview 4, Yokohama city; Ministry of the Environment, 2023). Thus, for instance, the emissions derived from setting up or disposing of the facilities can be counted towards the emissions of supplying municipalities, not consuming areas (Interview 4, Yokohama city). With such a separation in the process of assessing municipalities’ actions to reduce CO₂ emissions and the actual reductions, the hinterlands’ contributions do not get fully recognised and documented, even more so if they cannot locally consume the electricity they produce. The discussions about such gaps or the municipal-level three-scope carbon emissions are not yet taking place in the country, at least not in a major way (Interview 4, Yokohama city). Nonetheless, dealing with the emissions beyond city boundaries caused by urban activities is another challenge for cities to overcome (Wiedmann et al., 2021). At the same time, not addressing this challenge could diminish the hinterlands’ own environmental efforts and make the relationships based on metabolic links less positive and symbiotic than they could potentially be.