Questioning Waste Through Urban Metabolism:
Technologies, Scales, Practices
Thesis submitted by Andrea BORTOLOTTI
in fulfilment of the requirements of the PhD Degree in Art of Construction and Urban Planning ( « Docteur en Art de bâtir et urbanisme » )
Academic year 2019-2020
Supervisor: Prof. Geoffrey GRULOIS Laboratory on Urbanism, Infrastructures, and Ecologies (LoUIsE)
Thesis jury:
Thesis submitted by ANDREA BORTOLOTTI in fulfilment of the requirements of the PhD Degree in Art of Construction and Urban Planning
« Docteur en Art de bâtir et urbanisme » Academic year 2019-2020
THESIS SUPERVISOR Prof. Geoffrey GRULOIS
Laboratory on Urbanism, Infrastructures, and Ecologies (LoUIsE)
THESIS JURY Prof. Axel FISHER
(Université libre de Bruxelles, Chair and Secretary) Prof. Geoffrey GRULOIS
(Université libre de Bruxelles, Supervisor) Prof. Luisa MORETTO
(Université libre de Bruxelles) Prof. Sybrand TJALLINGII (Delft University of Technology) Prof. Sabine BARLES
(Université de Paris 1 Panthéon-Sorbonne)
This thesis was conducted at the Université libre de Bruxelles, Faculty of Architecture La Cambre-Horta, as part of the activity of the LoUIsE research centre and the Metrolab Brussels project.
This thesis explores and discusses the issue of urban waste through the lens of urban metabolism. Although research on waste largely focuses on the technical aspects of waste treatment and management, current demands for a “sustainable” and “circular” transition call for a broadening of the scope of analysis exploring new integrative approaches. In the same way, urban metabolism research is widely interpreted in its most technical sense, as the analysis of energy and material flowing into, within, and out of cities, even though scholars are now calling for more interdisciplinary engagements to better understand the connections between these flows and their underpinning sociotechnical systems. This thesis aims to test the capacity of the “metabolic lens” to build insights into the complexity of contemporary waste management and recycling, combining the more technical and socio-political stances of urban metabolism research. To do so, it gathers three research projects that build on different epistemological angles and research methods dealing with the issue of biowaste, focusing in particular on (i) decentralised treatment technologies, (ii) waste management scales, and (iii) waste recycling practices. Analyses are based on extensive literature review (for technologies) and empirics collected in the case of the city-region of Brussels (for scales and
practices). If the results of these works aim to potentially support
decision and policy-making processes in the current sustainable and circular transition, for the purposes of this thesis, they serve to stage a conclusive reflection on the contribution of the metabolic lens and the way to steer more integrative engagements in urban metabolism research.
EN
ACKNOWLEDGEMENTS
This thesis is the result of a research path undertaken over the past five years at the ULB’s Faculty of Architecture that would have not been possible without the support of a number of institutions and the contribution of many people. First of all, it has been made possible through the financial support of the Brussels ERDF programme (2014-2020) to Metrolab, Brussels Metropolitan Laboratory. The ULB’s Mini-Arc seed money grant allowed me to embark on this journey the first year of my doctorate, and Bruxelles Environnement funded some of the work contained in this thesis. A number of people have brought me here. I would like to thank in particular my supervisor Geoffrey Grulois, and the members of my thesis committee Luisa Moretto, Axel Fisher, and Sybrand Tjallingii for their time, precious advices, and insightful questions. I’m especially grateful to my supervisor for his confidence and the freedom he gave me to do this work.
I am also grateful to the entire team from Metrolab: the coordi-nators Benoît Moritz, Jean-Michel Decroly, Mathieu Berger, Bernard Declève, and Geoffrey Grulois, the postdoctoral researchers Marco Ranzato, Christian Dessouroux, Roselyne de Lestrange, Louise Carlier, and Maguelone Vignes, and doctoral comrades Pauline Varloteaux, Corentin Sanchez-Trenado, Simon Debersaques, Bap-tiste Veroone, Marine Declève, Barbara Le Fort, and Anna Ternon. Special thanks to the project managers Sara Cesari and Louise Prouteau for their precious support and patience in carrying out the fundamental practicalities of doing research.
in Brussels, and Simon De Muynck for taking the work outside the academic circles. I want to extend my gratitude also to the editors of the journals in which the chapters of this thesis have appeared, Hervé Corvellec, David Peleman, Bruno Notteboom, and Michiel Dehaene, and the anonymous reviewers for their very constructive and helpful suggestions. Thank you Sabine Barles for accepting being part of the jury. I was lucky to found myself working on a topic that attracts some interest and which is dealt with by a number of researchers in Brussels. Thank you all for bringing fresh ideas and fueling the debate: Aristide Athanassiadis, Emilie Gobbo, Julie Marin, Koenraad Danneels, Griet Juwet, Anastasia Papangelou, Vanessa Zeller, Greet De Block, and Daniela Perrotti.
1 INTRODUCTION 10 12 14 15 17 20 21 23 25 27 31 36 39 39 42 42 43 43 44 45 45 46 48 50 53 1.1 WASTE, RECYCLING, AND URBAN METABOLISM
1.2 METROLAB BRUSSELS AND LoUIsE 1.3 STRUCTURE OF THE THESIS
2 LITERATURE DISCUSSION
2.1 INTRODUCTION
2.2 URBAN METABOLISM AND FLOW ANALYSIS 2.3 POLITICISING URBAN METABOLISM
2.4 URBAN METABOLISM AND SOCIOTECHNICAL SYSTEMS
2.4.1 The life and death of urban networked infrastructures
2.4.2 Transition theories and perspectives
2.5 ASSEMBLAGE THINKING: TOWARDS A COSMOPOLITICAL URBAN METABOLISM 2.6 DISCUSSION: THE CALL FOR INTEGRATIVE APPROACHES
2.6.1 Advantages and prospects of spatial analysis
3.1 INTRODUCTION
3.2 QUESTIONING WASTE MANAGEMENT THROUGH URBAN METABOLISM
3.3 KNOWLEDGE GAPS
3.3.1 Technologies: decentralised treatments 3.3.2 Scales: waste management
3.3.3 Practices: waste recycling
3.4 RESEARCH DESIGN AND METHODS
3.4.1 Technologies: extended materials flow analysis 3.4.2 Scales: political-industrial ecology
3.4.3 Practices: assemblage thinking
3 GOAL AND RESEARCH QUESTIONS 4 TECHNOLOGIES: DECENTRALISED ORGANIC RESOURCE TREATMENTS 4.1 INTRODUCTION
4.2 SCOPE AND RELEVANCE OF DORT FOR URBAN BIOWASTE TREATMENT
4.3 METHODOLOGY: DESIGN AND COMPILATION OF
76 77 80 81 104 110 126 127 130 134 142 143 147 147 150 155 157 158 161 5.1 INTRODUCTION
5.2 UNDERSTANDING THE CITY AS A RESOURCE STOCK
5.3 UNRAVELLING THE POLITICAL ECOLOGY OF BRUSSELS BIOWASTE MANAGEMENT 5.4 REWORKING THE BRUSSELS BIOWASTE METABOLISM 5 SCALES: A POLITICAL -INDUSTRIAL ECOLOGY OF BIOWASTE MANAGEMENT FOR BRUSSELS 6 PRACTICES: THE ASSEMBLAGES OF PRIVATE WASTE MANAGEMENT AND RECYCLING REFERENCES 164 189 LIST OF FIGURES
6.1 WASTE MANAGEMENT AND RECYCLING PRACTICES
6.2 ASSEMBLAGES AND THE POLITICS OF WASTE RECYCLING
6.3 THE RESEARCH CONTEXT: THE CASE OF THE ANDERLECHT MARKETPLACE IN BRUSSELS 6.4 FROM DISCOURSES TO PRACTICES
6.5 USER PERSPECTIVES 6.6 CONCLUSION
7 GENERAL DISCUSSION
7.1 WHAT POTENTIAL FOR THE “METABOLIC LENS”?
7.1.1 Technologies: spatial vs technical capacities 7.1.2 Scales: generalised vs place-based management 7.1.3 Practices: globalism vs locality
7.2 URBAN METABOLISM AND DESIGN: TOWARDS MORE INTEGRATIVE RESEARCH PRACTICE
7.2.1 Design thinking for integrative science 7.2.2 Metrics for transformation
4.5 DISCUSSION AND ANALYSIS OF EMPIRICAL RESULTS
1
Post-consumer waste is estimated to account for almost 5% of global greenhouse gas emissions (Hoornweg & Bhada-Tata, 2012).
2
According to the European Commission, the circular economy will “boost the EU’s competitiveness by protecting businesses against scarcity of resources and volatile prices, helping to create new business opportunities and in-novative, more efficient ways of producing and consuming” (European Commission, 2015, p. 2).
3
See for instance the special issues of the Journal of Industrial Ecology (2017) “Exploring the circular economy” and Resources, Conservation and Recycling (2018) “Advances in the Circular Economy”.
1.1 WASTE, RECYCLING, AND URBAN METABOLISM
Proper urban solid waste management is a top priority in the sustainable development agenda. The generation of urban waste meets some of the most pressing contemporary challenges such as climate change, ecosystem loss, environmental pollution, and health hazards.1 In Europe, the common strategy on waste
preven-tion and recycling (European Parliament and Council, 2008) aims at paving the way towards a “recycling society” by decoupling economic growth from natural resource consumption. Within this framework, the concept of “circular economy” has gained traction among businesses and policy makers for its promises to increase resource use efficiency boosting new economic cycles in times of crisis.2 Research has also flourished as shown by the
increasing number of publications on the topic.3 The concept refers
to business models that aim to extend the life span of materials and products through reuse, repurposing, and recycling, reducing waste generation and improving the use of secondary raw materials in production cycles (Cossu & Williams, 2015; Ghisellini, Cialani & Ulgiati, 2016; Tisserant et al., 2017).
Although expectations are high, there is a significant gap between promises and reality regarding how to steer and support the transition towards a circular economy. As waste is the final stage of a linear economy based on extraction, production, and consumption, transforming it into a resource—as promoted by the circular economy—is no easy task. Business models are uncertain, due to the low value of recycled materials, and separate waste collection schemes require the implementation of technical and financial capabilities, resulting in higher costs and complexity of the overall waste management. In particular, and focusing on cities for their critical role in the use of resources, rethinking the urban metabolism, intended as the way material resources are circulated
4
This thesis uses the definition of biowaste given by the European Commission as the “biodegradable garden and park waste, food and kitchen waste from households, restaurants, caterers and retail premises, and comparable waste from food processing plants. It does not include forestry or agricultural residues, manure, sewage sludge, or other biodegradable waste such as natural textiles, paper or processed wood.” This definition was taken from the European Commission’s DG Environment website. Retrieved from http://ec.europa.eu/ environment/waste/ compost/index. htm (accessed on 08/05/2019) 5 These data are provided by the European Compost Network. Retrieved from https://www. compostnetwork.info/ policy/biowaste-in-europe/ (accessed on 16/11/2018)
in the urban environment, presents a formidable challenge to the world today. This is undertaken from multiple disciplinary angles, as knowledge on this topic is still incomplete. This thesis aims to contribute to this interdisciplinary endeavour, exploring the issue of waste through the lens of urban metabolism.
Based on the model of thesis by publication, it consists in an essay that attempts to build coherence among different published papers of which I am the first or sole author. Although these heterogeneous works differ in their methods, objectives, and results, they are driven by the same motivation: building a more thorough understanding of solid urban waste management with the aim to support decision and policy-making processes in (or at least assume more a conscious position with respect to) the current sustainable and circular transition. These works are based on studies, exchanges, fieldwork, and observations gathered over the past four years as part of my doctoral training in the Art of Construction and Town Planning at the Université libre
de Bruxelles on the issue of urban waste, and in particular on the
recirculation of biowaste (food and garden waste) in the case of Brussels, Belgium.
There are several reasons behind this focus on biowaste.4
Firstly, its relevance in terms of quantity within the urban waste stream—or Municipal Solid Waste (MSW)—composed by the miscel-laneous solid wastes from residential, commercial, and institutional sources. Official data reports that 245 million tonnes of MSW were generated in 2017 in the European Union, equivalent to 487 kg per capita (Eurostat). It is estimated that 37 per cent of this waste is biodegradable (e.g. food waste and scraps, paper, and cardboard, certain textiles, etc.), meaning it is capable of undergoing biological decomposition (European Environment Agency, 2013). This means that about 90 million tonnes of biowaste are produced annually (180 kg per capita), of which less than a third is separately collected, the rest being treated with the residual solid urban waste in landfills (31 per cent) and incinerators (26 per cent).5 Nevertheless, disposing of
biowaste in landfills generates well-known environmental hazards (e.g. leachate and methane production), while burning it in incinerators and waste-to-energy plants seems a contradiction, given the high moisture content and low calorific value of organic matter.
6
See the press release of 22/05/2018 by the Council of the European Union. Retrieved from https:// www.consilium.europa. eu/en/press/press-releases/2018/05/22/ waste-management- and-recycling-council-adopts-new-rules/ (accessed on 04/11/2018). 7
See, for example, the review of “zero-waste” initiatives that have recently sprung up in France by ADEME, Hajek, and Diestchy (2019).
amendments to the European Waste Directive 2008/98/EC have tightened MSW recycling targets, making it mandatory for member states to ensure that biowaste is either collected separately or recycled at the source by 2023.6 On the other hand, voices against
waste incineration have been raised globally by zero-waste associ-ations (for example the Global Alliance for Incinerator Alternatives, GAIA; Friends of the Earth Europe, etc.) which consider it threatening waste prevention and recycling priorities, and locally by compost networks that consider it a waste of valuable resources when it concerns the incineration of the organic matter (e.g. the European Compost Network). Moreover, a multitude of intergovernmental agency campaigns and programmes (e.g. UNEP) and citizens’ and/ or activist initiatives (e.g. dumpster diving) have coalesced in recent years around the fight against food waste, perceived as a persistent social and environmental challenge of contemporary society.7
Thirdly, it is also justified by growing expectations regarding energy and nutrient recovery and extraction of other valuable biochemicals from biowaste. Within the framework of the bio-econ-omy, circular econbio-econ-omy, cradle-to-cradle, and blue economy theory (Ghisellini et al., 2016), biowaste is increasingly seen as an untapped source of valuable elements such as nitrogen (N) and phosphorus (P), two essential fertilisers for modern agriculture, for which commercial production depends on phosphate rock reserves concentrated in a limited number of countries (e.g. China and Morocco). According to the Ellen MacArthur Foundation, a think tank whose mission is to promote circular economy principles, Europe could meet as much as 30 per cent of today’s—almost entirely imported—demand for phosphorous used in synthetic fertiliser by increasing the recovery of phosphorus from sewage sludge and biodegradable solid waste (Ellen Mac Arthur Foundation & McKinsey Center for Business and Environment, 2015, p. 79). On the other hand, driven by renewable and climate change policies and incentives, anaerobic digestion technology has spread in Europe for the production of biogas and nutrient-rich digestate using household biowaste as main feedstock of production (Scarlat, Dallemand & Fahl, 2018).
1.2 METROLAB BRUSSELS AND LoUIsE
by the Brussels-Capital Region through its European Regional Development Fund (ERDF) programme for 2014-2020. The project, which involves 12 doctoral and postdoctoral researchers from different disciplinary fields (architecture, urbanism, sociology, and geography), focuses on various components of Brussels’ regional policy inspired by the European strategy for “green, smart, and inclusive” development. The overall project objective is twofold: firstly, conducting reflection on the ERDF programme for Brussels and the results of some of its 46 projects pertaining to access to employment, research, circular economy, innovation and improving the living environment; secondly, testing new forms of academic engagements on the ground, focusing on the territorial embed-dedness of public programmes and policies, and looking at the practices, strategies, and tactics displayed by architects, planners, policy-makers and ordinary urban residents in their attempts to substantiate and negotiate policy objectives. Metrolab offered a unique opportunity to test transdisciplinary research gathering scholars, practitioners, and activists who share common urban issues within the framework of public conferences, seminars, and workshops.
In particular, the activity of Metrolab takes shape first and foremost through the organisation of MasterClasses open to international scholars and students that foresee the pooling of individual researches within the framework of two-weeks intensive workshops, the results of which are published in form of compendium of theoretical essays and design explorations. These publications, which gather a wealth of information on the work conduced on Brussels, aim to serve as a tool for broadening communication, stimulate debate, and, ultimately, influence regional planning.8
My individual research task intended to contribute to the debate on Brussels’ waste metabolism and the possibilities to improve its material cycles, which appears among the top priorities of regional programmes and plans.9 During this period, I have
been actively engaged in different groups, carrying out fieldwork, making contact with regional and local stakeholders, and organising seminars and workshops on the topic of urban metabolism, circular economy, and their application in Brussels. Moreover, this activity has intertwined with other studies I have conducted within the Laboratory on Urbanism, Infrastructures and Ecologies (LoUIsE) of the ULB’s Faculty of Architecture—a partner of Metrolab—and in close collaboration with other organisations and firms (Latitude
8
The first MasterClass was held in January 2017 and focused on the issue of urban inclusion (see Berger, Moritz, Carlier & Ranzato, 2018). The second MasterClass was held in January 2019 and focused on “urban ecology”, “urban metabolism”, and the “circular economy” (Declève, Grulois, de Lestrange, Bortolotti & Sanchez Trenado, 2019).
9
10 Here, research strategies and tactics are intended as types of research designs and means for collecting and analysing information as in Wang & Groat (2013)
Platform, OWS Engineering, IDEA Consult) on the issue of biowaste. These studies were funded by the Brussels Environment agency and have focused respectively on the scope of decentralised biowaste treatment (Bortolotti, De Muynck & Kampelmann, 2016); the estimation of potential biowaste production and collection in the Brussels-Capital Region (Bortolotti et al., 2018a); and the feasibility of building and operating an industrial biowaste treatment plant within the regional borders (Bortolotti et al., 2018b).
1.3 STRUCTURE OF THE THESIS
This thesis consists of 7 chapters. Chapter 1 introduces the research topic and framework. Chapter 2 discusses urban metabolism liter-ature through a range of disciplinary approaches, from engineering to geographical and social sciences. The purpose is to enable a conversation between different theorisations of the metabolism of cities, unfolding their research scope, methodology, contribution, and limits. Chapter 3 highlights the knowledge gaps identified within urban metabolism research and waste scholarship vis-à-vis (bio)waste management and recycling. Moreover, it outlines the research strategies and tactics10 proposed to address these gaps.
2.1 INTRODUCTION
The study of urban metabolism—intended as the set of interrelated socioeconomic and physical processes that result in specific material and energy stocks and flows within geographically-bounded systems—is an interdisciplinary endeavour that has been under-taken in environmental sciences, engineering, political economy, and geography alike (Broto, Allen & Rapoport, 2012; Christopher Kennedy, Cuddihy & Engel-Yan, 2007; Pincetl, Bunje & Holmes, 2012).
According to Newell and Cousins (2015, p. 704):
“urban metabolism can be collectively conceptualized as a ‘boundary metaphor’ […] whereby scholarly communities might interact through empirical practice and as a means to explore the friction between the varied epistemologies, methodologies, and framings of urban metabolism.” The urban metabolism debate is rooted in the nineteenth century Malthusian fear for overpopulation and in the understand-ing—based on early chemistry—of the importance of the nutrient cycle (of nitrogen, phosphorous and potash) for agricultural produc-tion (Barles, 2005; Fischer-Kowalski, 2002). Marx first transported the concept of metabolism into the social sciences to describe the process of human transformation of nature through labour. His theory of the “metabolic rift” between nature and society, or city and countryside, generated by capitalist modes of production (e.g. large-scale agriculture) was deeply influenced by chemist Justus Von Liebig, who expressed concerns about missed opportunities of recirculation in agriculture of human and animal wastes that were accumulating and polluting cities, and which would inevitably lead, in his view, to the spoliation of agricultural soils (Foster, 1999).
With the renowned environmental concerns of the second half of the twentieth century—marked by the oil crisis in the 1970s, the rise of modern ecology, and systems engineering (H. T. Odum, 1970; Wolman, 1965)—the metabolism framework has mainly been established in the form of an “industrial ecology” (Ayres & Ayres, 2002; Erkman, 2004), a quantitative and technical approach and a tool to envision more “sustainable” cities (Baccini & Brunner, 1991; Barles, 2010a; Fischer-Kowalski & Hüttler, 1998; Hendriks et al., 2000; C. Kennedy, Pincetl & Bunje, 2011; Oswald & Baccini, 2003). Since then, cities and regions have been largely studied through the lens of their socio-material metabolism (Barles, 2010a; Christopher Kennedy et al., 2007; Weisz & Steinberger, 2010), namely, accounting for the material and energy exchange processes within cities and with the biosphere, of which waste and pollution are one of the outcomes. In particular, Material Flow Analysis (MFA) has developed and become more refined and precise with the aim of characterising the material needs and environmental impact of cities in what has been popularised as an increasingly “urban world”.11
At the turn of the new millennium, the urban metabolism approach has thus proven to be attractive to technicians and decision makers who support the promises of “green” growth and circular economy, looking at cities as the main agents of change (UNEP, 2011). The underlyng hypothesis of these concepts is that the shift from a linear take-make-waste model to a circular and regenerative one could pave the way for the transition towards more sustainable use of resources, reducing the overall generation of waste and facilitating the recovery of waste products as sources for new products. For cities, this pursuit is often portrayed as a technical and design endeavour to become more resource efficient, to develop regulations to reduce, reuse, and recycle materials, and to foster local economic activities. In the tradition of the “ecological modernisation” that has established with the institutionalisation of early environmental movements of the 1960s, this approach frames waste and pollution mainly as design flaws and a matter of inefficiency, rather than calling for structural change and the need to address basic social contradictions (Hajer, 1995; see also Harvey, 1997).12 Nevertheless, and beyond a simple ecological
modernisation, steering the transition towards a less environmentally damaging and resource consuming urban metabolism is a much complex task with deep political implications which involve, new modes of governance, day-to-day politics, and citizenship.
11
Although urban metabolism research has largely focused on quantifying energy and material flowing into, within, and out of cities, the same research framework holds the capacity to navigate the complexity that the sustainable and circular transition entails, drawing on different epistemological angles such as systems theory, evolutionary biology, and post-structuralism. Research under the banner of urban metabolism has in fact expanded over the last few decades in a wide range of disciplines, including political economy and social sciences, offering remarkable examples of critical studies. This thesis attempts to re-establish connections between the more technical and socio-political stances of urban metabolism research that have been present for some time now, severed across a multi-tude of specialised discourses and research practices. Firstly, this chapter offers an attempt (albeit partial) to reconstruct an overview of the vast literature that has been confronted with the concept of urban metabolism and the quest for a sustainable transition, highlighting the strengths and weaknesses of each theoretical tradition. The conclusion highlights how integrating a spatial and place-based perspective in energy and material flow analysis is what allows foreshadowing more interdisciplinary engagements in urban metabolism research.
Coupled with the “ecosystem perspective” that looks at the relation between the urban system and the biosphere (its nested, larger biophysical system) (Marina Alberti, 2007), MFA provides a systematic method to keep track of anthropogenic impacts on the environment associated with society’s economic and material activities (Fischer-Kowalski & Hüttler, 1998). This relates to the early understanding of the city as an organism—or ecosystem (Duvigneaud & Denayer-De Smet, 1977), the analysis of urban systems (e.g. transport, water and energy supply) based on ecological principles and methods (Girardet, 1996; Tjallingii, 1995), and the emphasis on the city as a parasite (E. P. Odum, 1989) that depends on other ecosystems to draw its sustenance and depollute its wastes (see also Zhang 2013). More recently, the organicist analogy, as well as the radical opposition between closed and balanced natural cycles and open and destructive human cycles, has been criticised as offering an inappropriate understanding of ecosystems by urban ecologists (Golubiewski, 2012). As recalled by Gezik (2013, p. 3): “an ecosystem is not equivalent to an organism because it is not under direct genetic control … and all its components, their functions and unchangeable layout are not predicted before its genesis.”
Drawing on developments in ecological theory and com-plex system theory (Holling, 1973), scholars are now increasingly expanding the scope of their analysis to include human activity as an integral part of natural ecosystems and understand cities rather as dynamic and adaptive socio-ecological systems (Marina Alberti, 2007). Meanwhile, the biological metaphor has been under-taken by other disciplines such as ecological economics and social ecology. For instance, applying material and energy flow accounting (MEFA) method to social systems at large, scholars at the Institute of Social Ecology in Vienna have identified different sociometabolic regimes (the hunter-gatherer, agrarian, and industrial regime) explaining fundamental changes in the society-nature relationship throughout history (Fischer-Kowalski & Haberl, 2007; Fischer-Kowalski & Hüttler, 1998).
According to Hodson, Marvin, Robinson & Swilling (2012, p. 792):
13
Firstly, data is normally provided on a national level (e.g. Eurostat), and secondly, cities’ hinterlands have an increasingly global dimension that goes well beyond their administrative boundaries.
systems within the wider nexus of ecological services (e.g., water supplies, soils, air quality, landfill space) and natural resource extraction (such as, e.g., fossil fuels or building materials that can be drawn from multiple sources). This is what could call the ‘recoupling’ of urban systems with the natural systems that support them.”
As such, and with due precautions because of the scarce harmonisation of available datasets and lack of a common definition of city boundaries (Chávez et al., 2018)13, MFA provides a powerful
tool, endowed with scientific legitimation and supported with data, to compare environmental performances across multiple sectors (energy and material consumption, waste and pollution emissions) within the city, and among urban systems (Weisz & Steinberger, 2010).
2.3 POLITICISING URBAN METABOLISM
The term “urban political ecology” (UPE) has made its appearance in academic literature arguably with Swyngedouw’s publication “The city as a Hybrid: On nature, society and cyborg urbanisation” (Swyngedouw, 1996). Traditional political ecology used to focus on conflicts generated over access, exploitation, and control of natural resources (land, water, etc.) within the global capitalist political economy as key drivers of environmental degradation (e.g. soil erosion, tropical deforestation, etc.), looking at rural con-texts in Africa and Latin America through empirical analyses (e.g. historical analysis, ethnography, and discourse analysis) (Blaikie & Brookfield, 1987). Combining political and ecological studies, these works explicitly link capitalist development with ecological change across multiple temporal and spatial scales. UPE scholars have shifted their focus on cities—more specifically North American cities e.g. New York (Gandy, 2003), Toronto (Desfor & Keil, 2004) and Los Angeles (Robbins, 2007)—by blending representational, discursive, ideological, and material constellations of uneven power relations, and foreshadowing theoretical synergies between political economy, political ecology, and Science and Technology Studies (STSs) (Heynen, 2014).
Within this framework, UPE scholars have reappropriated the notion of urban metabolism to describe the resulting hybrid socio-nature of cities, e.g. looking at how natural resources are transformed by and enrolled into the political, economic and social practices that shape cities’ form and function (Gandy, 2003, 2005; Heynen, Kaika & Swyngedouw, 2006; Kaika & Swyngedouw, 2000; Swyngedouw, 1996). As such, UPE contributes to the understanding of urban metabolism by situating sociometabolic flows within their political-ecological context, and the everyday practices of the governmental organizations and societal groups that manage them. On the other hand, being strongly rooted in historical materialism, UPE considers cities to be the result of historical-geographical processes of production of nature, where capital accumulation is understood as the primary force of social and cultural organisation (Cronon, 1992; Gandy, 2003; Swyngedouw, 1996).
due to the straightforward application of macro categories drawn from Marxian historical-materialism (e.g. class struggle, division of labour, capital accumulation), UPE falls into an opposite overly deterministic “social theory” (Swyngedouw, 2006a). Much emphasis is given to social relations—and class relations under capitalism in particular—rather than socio-ecological ones, in a way that the relationships between society and the biophysical world remain largely ignored. Secondly, and stemming from an overwhelming analytical and empirical focus on Northern cases (New York, Toronto, Los Angeles), as discussed by Lawhon, Ernstson & Silver (2014), UPE risks universalising particular “Northern ecologies” (see also Demaria & Schindler, 2016). Lastly, and due to a predominance of qualitative approaches, the use of the urban metabolism metaphor in UPE has become “stagnant”, in a way, according to Newell and Cousins (2015, p. 704), it needs to be reinvigorated “through the creative infusion of ideas and approaches from other two [urban and industrial] ecologies”. This recalls early criticisms to the discourses on political ecology, which pointed out the limited disciplinary engagement with biophysical and environmental sciences, questioning the place of ecology in political ecology and thus its contribution to the discipline (Walker, 2005).
Investigating how social relations of class, gender, and race shape urbanisation processes, UPE investigates sociometabolic flows largely as controlled, manipulated by economic forces at the expense of marginalised populations, reducing the scope of urban metabolism to a heuristic device through which capitalism is criticised (Demaria & Schindler, 2016). A growing number of scholars are thus calling for a more situated approach to urban political ecology, primarily concerned with the local context—its contingencies, ecologies, and politics (Lawhon, Ernstson & Silver, 2014; McFarlane, 2011a, 2013). The sociotechnical approach to the study of urban metabolism looks at urban infrastructure systems as socially embedded: shaped by a large set of actors that are, in turn, affected by their development.
2.4 URBAN METABOLISM AND SOCIOTECHNICAL SYSTEMS
sociotechnical systems as main drivers of the urban metabolism (Coutard, 1999; Coutard, Hanley & Zimmerman, 2005; Gandy, 2003; Grahm & Marvin, 2001; Heynen, Kaika & Swyngedouw, 2006; Swilling, 2011; Swyngedouw, 2006a). This literature focuses on the way sociotechnical innovations in water supply, sanitation, energy supply, and transport have changed the man-nature relationship in the course of the nineteenth and twentieth centuries, e.g. by extending the city’s capacity to import natural resources and use ecosystems far beyond the urban region to externalise the environmental costs of its growing waste and pollution. A constant refrain of STSs is that infrastructure systems cannot be exclusively understood as technical nor exclusively as social, but as the result of a “complex process of co-construction of systems, use(r)s and institutions” (Coutard, Hanley & Zimmerman, 2005). Infrastructures consist of physical components (pipes, roads, cables, transfer stations, etc.) that enable (or hinder)14 the distribution and access to natural
resources (water, electricity, and gas), goods (manufactured food and products), and services (waste collection and treatment facilities). They also include social components (users, laws, institutions, professional, and social networks) that are responsible for their construction, management, and transformation. The combination of the two produces the so-called sociotechnical regimes, e.g. “relative stable configurations of institutions, techniques and artefacts, as well as rules, practices and networks that determine the ‘normal’ development and use of technologies” (Smith, Stirling & Berkhout, 2005, p. 1493).15
This literature can be further split into two large theoretical bodies that share a common root in complexity theory, systems and coevolutionary perspectives (Holling, 1973; Hughes, 1987): governance studies of large technical systems (LTSs)—which have largely focused on control, management and regulatory issues of urban infrastructure networks (Coutard, 1999)—and studies on technological transitions (TT)—concerned with the multi-level dynamics of sociotechnical change (Geels, 2002). The two have been confronted over the past decade with the discourses on sustainability and the demand for adaptation of existing infrastructures, either driven by the emergence of new technologies (e.g. smart, decentralised technologies tailored to specific locations or user-groups), markets (e.g. the liberalization and privatisation of urban service provision) or public policies (e.g. stricter environmental regulation) (Guy, Marvin & Medd, 2011), with
14
“[The] construction of spaces of mobility and flow for some always involves the construction of barriers for others” (Graham, 2010, p. 12).
15
the aim of producing relevant insights for policy-makers looking to promote their transformation (Hodson et al., 2012).
2.4.1 THE LIFE AND DEATH OF URBAN NETWORKED INFRASTRUCTURES
LTS studies have traditionally looked at cities and urbanisation processes as the “loci and the foci” of technological, economic, and social innovation (Coutard, Hanley & Zimmerman, 2005). Early works by urban historians (such as Mumford, 1938/1970; Joel Arthur Tarr & Dupuy, 1988) have shown how the development of infrastructure networks has enabled the rise of the modern city in Europe and North America in the course of the nineteenth century. The modern ideal of a “networked city” (Joel Arthur Tarr & Dupuy, 1988) is described as the result of a successful alliance between state planning and “Fordist” model of production and consumption mediated by increasingly ubiquitous electricity, gas, telephony, and transport grids, which have brought remarkable growth of domestic mass consumption (Grahm & Marvin, 2001). Today, the success of the ideal of networked city is demonstrated by the fact that, at least in the global North, infrastructures have become the “invisible” backbone of everyday life, often taken for granted by their end users (Graham, 2010).
Nevertheless, at the end of the 1960s, despite their quasi universalisation in the cities of the global North, networked infra-structures and the modernist planning model that accompanied them, were put on social and political trial (Jacobs, 1961/1992; Joel A. Tarr, 1984). Cities in mature economies have begun experiencing signs of infrastructure decay and risk of collapse that cast shadows on the “promised delights of urban modernity that surrounded the modern infrastructural ideal” (Grahm and Marvin, 2001, p. 93). As Grahm and Marvin (2001, p. 93) put it: “the physical deterioration of infrastructure, the lack of spending on new facilities, and a huge backlog in maintenance and rehabilitation, actually threaten to slow and even reverse economic growth in cities.”. At the same time, authors such as Illich (1973) began questioning the dominant role of technocratic elites and innovations that were creating growing technological dependence—instead of greater autonomy—in industrial society.16
However, a technologically oriented approach to problem solving in both infrastructure and environmental crises soon
opened up a gigantic market of “technological fixes” (Joel A. Tarr, 1984). Towards the end of the twentieth century, the ideal of the networked city, based on the universalisation and centralisation of urban service provision, gradually made way for the processes of urban fragmentation and infrastructure unbundling of a “splintering urbanism” (Grahm & Marvin, 2001), driven by the emergence and application of new (ICT) technologies to urban infrastructures, the substitution of regulated monopolies with competitive markets, and the increasing territorial competition among corporate and state-owned companies (Coutard, 1999; Monstadt & Schramm, 2017). This globally implemented privatisation of networked infra-structures and technological development, as recalled by Swilling (2011, p. 84), reshaped social and spatial relations in cities as well:
“gave profit-seeking corporations access to natural resource flows (especially water, wastes, energy and mobility) during a period that was also characterised by accelerated GHG emission (70% since the 1970s) (Intergovernmental Panel on Climate Change 2007) and resource extraction (36% since 1980)”.
There is evidence now that the dominant neoliberal model of the past decades has coincided with unprecedented levels of global connectivity and physical throughput, and with a shift of environmental problems between nations of the global North and South (Dittrich, Bringezu & Schütz, 2012).
of the urban service provision, but rather as active agent whose engagement is critical for the purpose of improving the economic and environmental performance of the system (Coutard, 2010).
In addition to infrastructure retrofitting, which has become the hallmark of a global ecological modernisation that positions state governments and agencies as arbiters between the economy and the environment in the administration of cities and programme delivery (Brand, 2007), public policies now place significant emphasis on adjusting the aggregate demand of end users to reduce a city’s requirements. Within this perspective, citizens are called upon to adopt more “eco-responsible” behaviours, and their commitment (or lack thereof) in adopting such behaviours is depicted as critical for the success or failure of public policies and programmes (Lehec, 2018). 2.4.2 TRANSITION THEORIES AND PERSPECTIVES
While LTS studies look at cities and urbanisation processes, TT and the cognate discipline of transition management (Rotmans & Loorbach, 2009) focus on sociotechnical “niches”—emerging individual technologies, practices, and actors—as the loci for innovation (Fischer-Kowalski & Rotmans, 2009; Geels, 2002). Based on the observation that changes are non-linear and depend on the capacity of small initiatives to scale up and have significant impact on the system in the long run, Geels (2002) and his colleagues have developed a systemic approach for studying dynamic sociotech-nical transitions on a Multi-Level Perspective (MLP). MLP situates technological innovation within an interrelated three-level framework (micro-meso-macro). The micro level (also named “niche”) includes novel technologies and the small networks of actors learning how to use them to encourage scaling up at a higher level; the meso level (“regime”) includes existing technologies embedded into the “dynamically stable” configuration of institutions, practices, regulations; lastly, the macro level (“landscape”) is understood as the broader condition imposed by macroeconomic trends, cultural patterns, political culture, etc., which also applies pressures on existing regimes and creates windows of opportunities (Geels, 2002; Geels & Schot, 2007).
regime (Geels & Schot, 2007). Stemming from MLP, transition management is based on the assumption that steering system innovation requires: i) creating an arena for change (“space for niches”) where innovators and frontrunners can look beyond their own domain; ii) identifying long-term transition pathways and setting the agenda; iii) experimenting in a significant and measurable ways (learning-by-doing), and, iv) monitoring macro developments and changes at the regime level (Fischer-Kowalski & Rotmans, 2009). Considering that sociotechnical systems are the result of the coor-dination between heterogeneous sets of elements (infrastructure, user practices, and institutions) at the regime levels, and that the demand for innovation inevitably generates tension among them, reconfiguration processes occur when developments at multiple levels align and reinforce each other (Geels, 2002). It is now widely accepted that a sustainable transition requires integrated actions across sectors (industrial, commercial, institutional, etc.), scales (global, regional), and actors (public, private, community). The MLP, at this regard, calls for a multilevel governance at different scales of action.
While works in LTSs have stressed the importance of empirical analysis of institutional, technological, and organisational aspects of innovation, they have often neglected the user’s perspective (Furlong, 2011), remaining largely descriptive. On the contrary, MLP and transition management have integrated users into the general equation and development of models of transition pathways, yet tending to a straightforward generalisation with little concern for specific space-place issues (Hodson & Marvin, 2010; Hodson et al., 2012). Much emphasis is given on technological niches as principal locus of regime change (Geels & Schot, 2007), with the risk of producing the misleading impression that there exists a particular transition pathway that is relevant for all contexts. Although the two perspectives have contributed to improving the understanding of the way in which urban infrastructures and their transformation affect sociometabolic flows, similarly to UPE, the insights they provide are largely qualitative and lack of integration with more quantitative data. On the other hand, the translation of transition perspectives often produces reductionist and technocratic results, this is why, according to Monstandt (2009, p. 1930):
management of urban transition strategies. Instead, the huge spatial variation of sociotechnical regimes and the shaping of technological transitions by urban processes are mostly neglected.”
2.5 ASSEMBLAGE THINKING: TOWARDS A COSMOPOLITICAL URBAN METABOLISM In various ways, the previous sections have demonstrated the need for urban metabolism research to overcome abstractions of material flows analysis (such as in Industrial Ecology), and avoid the use of inherited and generic social theories (such as in UPE and MLP). A contribution that goes in this direction is offered by descriptive accounts that build on neo-materialist perspectives and embrace the concept of “assemblage”. This is not the place to review and discuss the extensive literature that deals with the concept in the field of urbanism17, but rather to (briefly) outline its
potential implications in the conceptualisation of cities, and by extension, their metabolism.
Being open-ended, complex, and multi-scalar systems con-stantly undergoing transformation, cities are a perfect ground for thinking in terms of assemblages (Amin & Thrift, 2002; Simone, 2011; Simone & Pieterse, 2017). Originally adapted from assemblage theory proposed by philosophers Deleuze and Guattari (1987) and further developed by authors such as Manuel De Landa (2006) and Jane Bennet (2010), the concept of assemblage is used to describe the rhizomatic coming together of humans and non-humans, and the way actor-networks are put in place and stabilised.18 In social
sciences research, the notion is increasingly used to connote indeterminacy, emergence, becoming, processuality and the sociomateriality of phenomena.
The notions of symmetry and heterogeneity are key to the meaning of assemblage, where symmetry refers to the distribution of agency (the capacity to produce an effect) across humans and non-human actors (Beauregard, 2015). The concept, which emerges between the lines of various poststructuralist discourses (e.g. Actor-Network Theory, feminist, and post-colonial studies), resonates with those of cyborg (Haraway, 1991) and hybrid (Latour, 1993), used to describe networks of actors (people, things), processes, symbols, information, etc. that span over the social and natural realms in such a way that they reject modern divisions between
17 See for instance the debate initiated by Colin McFarlane (2011a), and continued by Neil Brenner and colleagues (2011) and AbdouMaliq Simone (Simone, 2011) in the journal CITY. See also (Blok & Farias, 2016).
culture and nature. Public issues such as nuclear power, GMOs, global warming, waste and pollution are often presented as examples of hybrids (Callon, 2006). Hybrids, networks, and assemblages alike have a generative capacity as they allow the deconstruction of inherited social categories and build new worlds composed of new associations.19 The notion of assemblage contributes
to the emergence of a cosmopolitics, intended as a politics of ontologies (Saito, 2015), where nature and society are not merely the backdrop for human activities, but are both constitutive parts and outcomes of heterogeneous relations in which humans are constantly entangled.
Two fundamental aspects of thinking in terms of assemblages are worth discussing for the purposes of this thesis: firstly, the ability to highlight the materiality and spatiality (in terms of relationships) of things, and secondly, the generative ability to project alternative sociomaterial configurations.
Assemblages are about processes rather than fixed forms. Thinking in terms of assemblages is therefore a priori against different types of reductionism (including the reduction of things to essences) (Kamalipour & Peimani, 2015). In this context, thinking in terms of assemblages offers an alternative to conceptualising cities and urban systems as an interlocked grouping of elements such as the biophysical, the technological, the social, etc. Instead, it focuses on the forces that shape urbanisation processes (e.g. discourses, institutions, spaces, technologies, knowledge, etc.), whether driven by biological or social mechanisms (e.g. ecological cycles, market and non-market forms of exchange, structures of power and authority, cultural traditions and information), across spatial and temporal scales. Assemblage thinking “blows up” the old dividing lines relating to sectors, scales, and geographical divides that characterise most urban and urban metabolism descriptions. By combining elements from politics, geography, and philosophy, it offers a “bottom-up” (Kamalipour & Peimani, 2015) and “process-based” (Anderson, Kearnes, McFarlane & Swanton, 2012) ontology that challenges conventional explanations of complex phenomena by focusing on the materiality of diverse urban configurations. For instance, describing the multi-level urban governance, and cross-scalar mix of institutional agencies, partnerships, business and interest groupings engaged in the making of urban politics (Allen & Cochrane, 2007; Anderson & McFarlane, 2011).
Moreover, it does not simply engage in empirical focus on how socio-spatial forms and processes are assembled, held in place, and made stable, but also works in different ways to open up or close down possibilities (Anderson et al., 2012). The concept holds both a descriptive and projective capacity, as it calls for the reframing of not only the comprehension of how urban assemblages (of ideas, materials, and people) come to be articulated across specific time-space, but also the (re)imagining of their combination in other spaces and configurations. As such, it has inspired and challenged urban designers and planners engaged in questioning enduring social theories embedded in planning theory and practice (Beauregard, 2015; Lieto & Beauregard, 2015; Yaneva, 2017). By extending agency to non-humans, assemblage thinking allows for the closer inspection of the materiality of urban processes and the “regenerative capacities of things” (Lieto & Beauregard, 2015), where each component of an assemblage (e.g. the infrastructure, construction, technology, network, etc.) maintains its own onto-logical status while associating with others, in such a way that it can play different roles on multiple planes acting differently within associations (Anderson et al., 2012).
Authors who build on assemblage thinking stress the framework’s ability to resist falling into pre-constituted theoretical assumptions, and many voices, from geography and political economy, have argued that the incorporation of ANT and assem-blage-inspired theory in UPE have potentially broader reach when investigating the urban socio-nature (Demaria & Schindler, 2016; Heynen, 2014; Lawhon et al., 2014). Examples in this sense range from the use of the notion of assemblage as alternative analytics for investigating alleged pathways of neoliberal privatisation, e.g. real estate developments (McGuirk & Dowling, 2009) or, supposed examples of failed urbanisation, e.g. informal neighbourhoods in cities of the global South (Simone, 2004b, 2004a) where, on the contrary, everyday survival strategies such as the pooling of urban resources show powerful alternatives to predominant capitalist development and metabolic discourses.
2011). Empirical accounts risk remaining anecdotal, and caught up in the enumeration of all the things that make up certain networks, without necessarily providing a theory as to how agency is distributed within the network. This is shown by the way authors building on assemblage thinking still refer to categories taken from outside the frame of the assemblage (e.g. social inequality) to orient critical analysis (McFarlane, 2013; Tonkiss, 2011). In addition, and despite interest on the materiality of things, quantifiable data is still poorly integrated into descriptive efforts.
To conclude, conceptualising cities and urban systems in terms of assemblages, or groupings, offers a relational perspective with a potentially broader scope that includes the role of non-humans (e.g. rivers, animals, particles) in the construction of urban worlds and the exploration of the ways in which these worlds are constantly reconfigured. Assemblage thinking shows a potentially broader reach than neo-Marxian theories when it comes to investigating the urban socio-nature (Kamalipour & Peimani, 2015) by welcoming non-humans into (urban) politics and thus contributing to the process of democratisation (Farías, 2011). This path-breaking ontological position offers an alternative to critically approach complex space/place issues inherent to political principles such as sustainability emphasising the regard on the materiality of things (Lieto & Beauregard, 2015), urban politics (McFarlane & Anderson, 2011), and urban life (Simone, 2011).
As recalled by Bennett (2010), the forces of contemporary cosmopolitan and globalization push towards the rethinking of the part-whole relation, overcoming the organicist model and accepting the coexistence of mutual dependency with friction and violence between parts.20 For cities, this means “focusing on the multiple
forces and assemblages that constitute urban common worlds, and on the conflicts and compromises that arise among different ways of composing their forms and limits” (Blok & Farias, 2016, p. 2). Ultimately, the notion of assemblage, whether used as a concept, descriptive lens, or an orientation, can help understanding urban metabolism not just as a matter of impalpable flows, nor exclusively of capitalist forces or sociotechnical regimes, but as the results of heterogeneous assemblages embedded in particular networks, ecologies and, most importantly, places.
20
21
Integrative studies involve wider collaboration among scholars (in interdisciplinary) and between scholars and societal actors (in transdisciplinary research) where “new knowledge and theory emerges from the integration of disciplinary knowledge” (Tress, Tress, & Fry, 2006, p. 17).
2.6 DISCUSSION: THE CALL FOR INTEGRATIVE APPROACHES
This chapter has focused on the ways in which scholars have offered different interpretations of the metabolism of cities by emphasising (i) energy and material flows analysis for steering more efficient use of resources, (ii) historical processes and issues of injustice inherent to capitalist urbanisation (land use speculation, gender and racial segregation, etc.), (iii) co-evolutionary trajectories of technologies, use(r)s, and institutions, and (iv) the need to grapple with the unstable materialisation of urban politics and urban life. These somewhat disparate literatures contribute in different ways to the comprehension of what the metabolism of cities is made of and what its study is meant for. The overview table [Tab 1a/b] casts light on the fundamental distinctions between the scopes, methods, contributions, and limitations of these different episte-mological approaches. In particular, it highlights how the ensemble of quantitative methods (e.g. MFA, life cycle assessments, carbon footprints, etc.) are the prerogative of a single “cluster” of urban metabolism research (Newell & Cousins, 2015), that of industrial ecology, whereas other clusters build exclusively on arguments based on qualitative methods and data.
In recent years, calls for more integrative21 engagements in
Tab 1a. Comparison between urban metabolism approaches: scope, methods, contribution, and limitations
APPROACH INDUSTRIAL ECOLOGY URBAN POLITICAL ECOLOGY (UPE) SCOPE Analyses the scale of
physical activity, the allocation of materials across economic sectors, and inefficiencies in productive systems.
Explains the urban metabolism as the result of historical-geographical processes where capital accumulation is understood as the primary force of social, cultural, and spatial organisation. METHODS Accounting methods:
Material flow analysis (MFA); Life cycle assessment (LCA); Environmental footprinting.
Historical analyses: discourse and document analysis, archival methods, interviews.
CONTRIBUTION Early recognition of resource consumption and pollution problems; it defines priority areas and steers effective policy for closing material cycles; it provides communication and synthetic tools.
Helps situate sociometabolic flows within the historical trajectories and resulting practices of governmental organisations and societal groups that manage them.
LIMITATIONS Little comprehension of structural (political, economic, social) processes and the complexity
of change. No spatial considerations (aspatial, apolitical).
Overly social deterministic; risks to universalise “northern ecologies” and is based on a preponderance of qualitative approaches.
EXAMPLES Baccini & Brunner, 1991; Barles, 2010b; Hendriks et al., 2000; Weisz & Steinberger, 2010
Angelo & Wachsmuth, 2015; Harvey, 1997; Heynen, 2014; Heynen, Kaika & Swyngedouw, 2006; Loftus, 2012;
Tab 1b. Comparison between urban metabolism approaches: scope, methods, contribution, and limitations
APPROACH SCIENCE AND TECHNOLOGY STUDIES (STSs)
ASSEMBLAGE THINKING SCOPE Understands cities and
urban infrastructures as sociotechnical artefacts; it situates sociotechnical innovations within evolutionary paths. Understands cities as heterogeneous assemblages of interrelated and
interdependent (human and non-human) categories.
METHODS Empirical analyses, and technology and policy analysis.
Fine-grain description, ethnographic research, and participatory observation.
CONTRIBUTION It links technologies with institutional arrangements and promotes an incremental understanding of innovations conceptualizing different levels of technological change.
Distributes agency across entities; highlights the role of non-humans in social and political organisation; helps navigate urban governance scales; sustains critical engagement with the spatiality and materiality of things. LIMITATIONS It focuses mainly on
technological innovations with no or limited spatial considerations; based on a preponderance of qualitative approaches.
Risks being exclusively descriptive and not providing explanations for social processes; does not integrate quantitative metrics.
EXAMPLES Coutard, Hanley &
Zimmerman, 2005; Coutard & Rutherford, 2016; Geels, 2002, 2011; Geels & Schot, 2007; Grahm & Marvin, 2001; Rutherford & Coutard, 2014
22
By research strategy we mean the set of methods selected to implement a research design. Examples of commonly used research methods are surveys and experiments in quantitative research and observation, interviews, and focus groups in qualitative research.
23
Most of the efforts towards a definition of mixed research methods have focused on finding exploratory sequences to combine quantitative and qualitative research components. Croswell (2014) describes three basic mixed methods designs: (i) “Convergent Parallel”, where the researcher collects both quantitative and qualitative data at the
on social processes, with far less attention to ecological ones or the links between them and material flows.
Here, the limits are not inherent to the choice of the use of quantitative methods per se—working with synthetic data and statistical procedures—or qualitative methods per se—which seek to understand phenomena in individual terms and within specific contexts. Instead they are the result of the lack of integration and combination of the two. For instance, the limits of quantitative research emerge when data on energy and material flows and stocks are used in an acritical manner and dissociated from the underlying socio-political and biophysical features that explain how they are used and by whom, in cities and across geographical space. As discussed by Pincetl & Newell (2017, p. 381), this is the case with data that is instrumentally conceived, produced, and analysed for the purpose of governance modes that assume “cities can be measured, monitored, and treated as technical problems to be addressed through technocratic solutions”.
Reducing complex patterns of interactions to a set of ana-lytically measurable variables, a quantitative understanding offers the promises of greater control and predictability, yet ignoring other important and non-measurable factors that connect nature, technology, and society in one dynamic process. There are whole sets of nature-society relationships that resist quantification and are typically excluded from analysis, in a way that resulting models risk of being used to reproduce narrow technical agenda, obscuring other forms of knowledge and action. On the other hand, qualitative and critical approaches are considered more apt to illuminate relations in complex systems, describing things in their context and interpreting phenomena in social and individual terms. Yet, descriptive efforts may not be enough, as the real challenge in transitional endeavours is understanding wider connections within and between different operating systems so as to rework them in operational ways.
Within this context, mixed methods that combine qualitative and quantitative research and data emerge as an option for seeking ways to marshal the benefits of two or more research strategies in a research study (Creswell, 2014; Tashakkori, Teddlie & Teddlie, 2003; Wang & Groat, 2013).22 The advantage of such an approach
that is derived from a qualitative method is confronted and merged with knowledge derived from quantitative methods in order to answer a common research question, eventually producing new theory and methods that can be developed and may become available for further research.23 Although we are sympathetic with
mixed methods strategies, we argue that further advancements in urban metabolism research require far bolder actions. Fostering cross-fertilization of different intellectual traditions is indeed, first of all, an epistemological question rather than a question of method. The difficulties of integrating disciplines in urban metabolism research reside not only in insufficient scientific engagements, but also in the nitty-gritty and mundane practicalities of working across research groups, the limited time frame and scope of research projects, the lack of meta-studies making inter- and transdisciplinary urban metabolism research available to scholars and practitioners and, in general, the absence of links between knowledge production and action (see for instance Athanassiadis et al., 2019).
In that respect, we observe the opportunity to open a fruitful dialogue between urban metabolism research and urban design and planning beyond the attention shown in recent years by urban practitioners (architects and urban designers) to the concept of urban metabolism for modelling complexity and controlling ecologically disruptive substance flows.24 In most recent design
explorations urban metabolism is understood exclusively in the form of industrial ecology, and design intervention is interpreted as a way to control metabolic flows through technological inter-ventions (Bortolotti, Grulois & Ranzato, 2018; Ibañez & Katsikis, 2014). Yet, there is growing awareness that if architects and urban designers can contribute to the debate on urban metabolism, they can certainly not achieve this by making the “metabolic machine” more efficient.25 Instead, it is assuming a broader understanding of
design as integrative discipline of knowledge, communication, and action (Buchanan, 1992) that is possible to glimpse its potential contribution to urban metabolism research. This will be discussed in more depth in the conclusive chapter of this thesis.
Suffice to say here that a main concern of urban design discipline is the interrelationship between society and space (Madanipour, 1997). On the basis of what has been said so far, it appears that a better contextualization and spatialisation of urban energy and material flows is what can operationally foreshadow the dialogue between disciplinary approaches. As the spatial
same time, analyses them separately, then compares the results to see if the findings confirm or invalidate one another; (ii) “Explanatory Sequential”, which mainly involves the collection of quantitative data, the analysis of the results, and their use at a later stage to plan the qualitative analysis to explain these results; (iii) “Exploratory Sequential”, starting on the contrary with a qualitative phase, followed by a quantitative phase that builds on the first phase with the intent to develop better measurements and see for generalised rules.
24
Oft-cited examples of design explorations working on the concept of urban metabolism are the work by Oswald and Baccini (2003) and their students of ETH Zurich on Swiss urbanisation, or those presented at the 6th International Architecture Biennale of Rotterdam held in 2014, “Urban by Nature”. Retrieved from https://iabr.nl/en/ zoek/urban%20by%20 nature (accessed on 29/06/2019). 25
arrangement of energy and material stocks and flows is the result of specific natural, technical, and social dynamics and their inter-relation (e.g. the physical geography, technological know-how, and distribution of resources in particular time-space), integrating a spatial and place-based perspective is what can help steering more integrative engagements in urban metabolism research. The following section attempts to clarify what we mean by spatial perspective and what makes up a spatialized approach to the study of urban metabolism.
2.6.1 ADVANTAGES AND PROSPECTS OF SPATIAL ANALYSIS There are many examples of studies that integrate the spa-tial and geographical dimension into metabolic flows analysis. Environmental economists and sociologists have emphasised the importance of measuring energy and material flows across time and space, the limits of these flows and their environmental and socioeconomic implications (Haberl, Fischer-Kowalski, Krausmann & Winiwarter, 2016). In France, works in the field of “territorial ecology” have brought together urban planners, engineers, and biochemists who couple regional MFA with the analysis of the stakeholders and agents involved in material flows within territorial boundaries in order to question management methods and socioeconomic impacts (Barles, 2010b). More fine-grained spatial analysis coupled with traditional accounting methods was conducted in Los Angeles by urban planners (Pincetl, Graham, Murphy & Sivaraman, 2015) and geographers (Cousins & Newell, 2015). In particular, Cousins and Newell (2015) came with the proposal for a “political-indus-trial ecology” that integrates traditional indus“political-indus-trial ecology with insights from UPE. To do so, these authors combine the analysis of the hydrosocial cycle of the Los Angeles’ water supply with the spatialized quantification of its greenhouse gas emissions (GHG) (measured in CO2 equivalent per kWh). First, they retrace the origin of Los Angeles’ water sources on a map, highlighting the intensities of electricity consumption along the supply system (for water pumping, treatment, and distribution) to then point at some “hotspots” with greater environmental impacts.
important socioeconomic differences among and between urban populations and point toward policy and outreach that targets those populations most responsible for carbon emission” (Pincetl & Newell, 2017, p. 45). Similarly, Pincetl and colleagues (2015) match energy consumption in Los Angeles to income and build environment attributes in order to show how consumption patterns and institutional configurations shape the dynamics of Los Angeles’ metabolic flows. Ultimately, these studies highlight how spatially based analysis of flows and regulatory regimes can highlight meaningful strategies to affect the use of such resources.
What has been said so far is related to the above discussion regarding the need to frame data collection and analysis in a critical and reflexive manner. Kitchin (2014) and Pincetl and Newell (2017) critically discuss the use of big data (the millions of records of energy and water consumption by urban users) for “smart urbanism” and quantitative data for sustainability indicators (such as GHG emissions). Here, data on energy and material consumption are commonly collected in aggregate form at the city-wide scale and per urban sector (residential, transport, industrial, and service sectors) in order to generate benchmarks, sustainability metrics, and public policies at the same governmental level. However, they tell little about the social distribution of the environmental costs of resource consumption and waste production. For instance, sustainability metrics (GHG emissions) are used to stimulate the development of more efficient technologies rather than renegotiate the distribution of the environmental costs produced by these technologies (e.g. encouraging the purchase of low-emission cars rather than discouraging recourse to individual mobility in favour of public transport). As a result, derived environmental policies are largely out of reach for most residents, obscure, and detached from democratic processes.
and avoid the “empirical emptiness” (Holifield, 2009) that emerges between the lines of the criticisms to industrial ecology, UPE and transition theory alike. Secondly, measuring the distribution of these resources (and waste) flows across specific geographies allows to generate and rely on quantitative data to support or refute initial hypotheses and advance new theories. As such, it provides a comprehensive picture for better understanding (but also designing and managing) sociometabolic flows, moving beyond a merely technical basis and potentially involving a broader coalition of actors involved in their management.
What has been said so far does not intend to reduce space to a simple container of discrete actors and flows, but, on the contrary, considers it an active agent of their co-constitution: a
topologic space that emphasizes relations over fixed and absolute
