Assessing the ecological dimension of urban resilience and sustainability

ABSTRACT

We propose a framework for a package of Urban Sustainability and Resilience Indicators (USRI) based on a holistic approach to urban dynamics that we name the ‘pyramid of urban resilience and sustainability’. We start with a concise discussion of the concepts of urban resilience and sustainability, their synergies and trade-offs. We then make a point of the need for an interdisciplinary and holistic approach to assess progress towards or away from urban sustainability and resilience; and delineate an analytical framework that enables a comprehensive approach to ‘the urban’ by addressing not only ecological but also economic, sociocultural and governance dimensions. We critically reflect on its potential (and limits) by applying it to the case of Mexico City. The paper presents preliminary results for the ecological dimension of such a framework, and insights from the case of solid waste.

USRI offers the potential for a systemic approach to urban sustainability and resilience. Yet, some limitations are evident, mostly related to data availability at the urban level, complexity to aggregate and weight data, the limited efforts for knowledge coproduction and the incorporation of participatory processes, and the need to cautiously translate findings – and their inherent uncertainties – into decision-making.

KEYWORDS:

• Urban sustainability
• urban resilience
• urban planning
• urban indicators
• Mexico City

1. Introduction

In 2014, nearly 54% of the global population or 3.9 billion people lived in cities; by 2050, urban population may reach 66% (United Nations 2014). Such population growth will mainly be experienced in the developing world and could imply a duplication or triplication of the urban built environment, depending on economic and population dynamics (IPCC 2014).

The urban built environment covers between 0.2% and 2.7% of global ice-free land area (Schneider et al. 2009; IPCC 2014), accounting for 80% of global GDP and 71–76% of CO₂ emissions from global final energy use and between 67% and 76% of global energy use (IPCC 2014). Moreover, urban inhabitants consume two to three times more materials than their rural counterpart (World Bank 2010). Yet, profound inequalities persist within cities: 881 million people lived in slums¹ in 2014, compared to 791 million in 2000 (UNHABITAT 2016a), a figure that is expected to increase to up to 1.4 billion by 2020 in the ‘worst case scenario’ (UNHABITAT 2011).

As the main energy and material consumers, urban settlements have become the central driver of global environmental degradation and climate change. However, they could also be perceived as spaces of opportunity if they are renovated and built for both, environmental melioration and climate change adaptation and mitigation. Urban resilient and sustainable settlements have already been recognised as one of the main challenges for the twenty-first century within the Sustainable Development Goals;² however, the conceptual, theoretical and methodological frameworks, necessary to monitor progress in a comprehensive way, are still being developed.

Our starting point for this paper is the call for a holistic, interdisciplinary and systemic approach to urban sustainability and resilience, where sociocultural, economic, governance and ecological dimensions are integrated to move towards novel practices of policy, planning, decision-making and public engagement resulting in strategies implemented at multiple temporal and spatial scales (Neuman 1998; Boyd and Juhola 2015; Chelleri et al. 2015). In response to this, we present the ‘pyramid of urban resilience and sustainability’ as a holistic methodological approach and delineate a set of basic Urban Sustainability and Resilience Indicators (USRI) for monitoring urban sustainability and resilience progress or backlogs in the context of intense and rapid climate and socioecological change. Finally, we use the USRI to produce a general diagnostic of Mexico City – focusing on the ecological dimension of USRI – and explore the case of waste governance.

The objective of this paper is to delineate a comprehensive conceptual and analytical framework for monitoring and evaluating the state of the urban, and to critically reflect on its potential (as well as its limitations) by presenting preliminary results (focusing on the ecological dimension) from the case of Mexico City.

2. Urban sustainability and resilience: a theoretical and conceptual framing

Urban sustainability and resilience have gained importance in academic and policy arenas (as the 11th Sustainable Development Goal illustrates). In general terms, a robust urban agenda is expected to consider factors that improve the flexibility, adaptive capacities and sustainability of the urban system, to cope with diverse intensities of vulnerabilities co-constructed by climate change, environmental degradation and socio-economic, political and cultural dynamics.

However, there is a diversity of interpretations of the concepts of urban sustainability and resilience in terms of environmental, economic, social, demographic, and institutional objectives that could be pursued. In addition, there are different pathways to achieve such objectives. What is understood by urban sustainability and resilience thus defines the type and strength of actions, and their potential to either foster change or preserve the current state of affairs.

2.1. Urban sustainability

In broad terms, urban sustainability could be seen as the application of sustainable principles to the urban space. Despite such apparent clarity, urban sustainability has been questioned, not only because there are several understandings of sustainability and thus of urban sustainability (Haughton and Hunter 1994; Finco and Nijkamp 2001) but also because urban settlements do not currently fulfil the conditions of sustainability. The role of urban settlements in social and economic processes, embedded in concrete territorial spaces, demands increasing flows of resources and generates a diversity of socioecological impacts, often violating sustainability conditions (particularly when those are analysed from a metabolic or thermodynamic viewpoint (Baccini and Brunner 2012; Kennedy et al. 2011; Delgado Ramos, 2013; 2015a; Stossel et al. 2015).

Therefore, urban sustainability implies a desirable dynamic state of operation that persists over time, embracing intra- and intergenerational equity, in a context in which specific natural, physical, economic, political and sociocultural features are considered (Finco and Nijkamp 2001; Bithas and Christofakis, 2006; Hiremath et al, 2013). In a normative sense, urban sustainability can thus be defined as achieving a balance between urban development and the long-term protection of the environment while being inclusive, democratic, culturally diverse, and economically equitable (see Agyeman, Bullard and Evan, 2003; Lloyd-Jones, 2004; Swilling and Annecke 2012). The idea entails a recognition of, on the one hand, interdependencies between the urban and the environment, and on the other, the constraints related to local, regional and global biophysical limits, which ultimately implies operating below planetary boundaries thresholds (Steffen et al. 2015). This is also relevant since consequences of global ecological change, including climate change impacts, may lead to different types of local impacts and thus of responses and conceptions of the future of cities (Hodson and Marvin 2010; Derickson 2017). Several urban alternatives have been proposed as a means for anticipating, reducing or avoiding such impacts, from eco-polis (Downton 2009), ecocities (Caprotti 2015) and green-cities (Cambell 1996; Simpson and Zimmermann 2013) to smart cities (Hollands 2008; Caragliu et al. 2011; Neirotti et al. 2014), circular cities (Kennedy et al. 2011; Prendeville, Cherim, and Bocken, 2017) or those that promote ‘regenerative urbanism’ (Thomson and Newman 2016). With these multiple interpretations, both urban sustainability and urban resilience may play key roles as boundary objects (Meerow et al. 2016) or departure points for encountering visions, dialogue and coproduction of knowledge, consensus reaching and implementation of actions.

2.2. Urban resilience

Since Holling’s seminal paper (1973), the idea of resilience has evolved, diversified and been used by a range of scholars from ecology, complex systems theory, social sciences and others. Within the ecology field (see Gunderson and Pritchard 2002; Brand and Jax 2007), resilience is understood as ‘…the magnitude of disturbance that can be absorbed before the system changes its structure by changing the variables and processes that control behaviour’ (Brand and Jax 2007). In other words, it is the capacity to experience shocks while retaining function, structure, feedbacks and identity (Walker et al. 2006), through the interplay of disturbance and reorganisation, transformability, learning and innovation (Adger et al. 2005; Folke 2006; Brand and Jax 2007). In contrast, when applied to the social world, resilience means the ability of individuals and communities – including their means of production, distribution and consumption – to cope with external stresses and disturbances produced by social, political or environmental change, or to bounce back from an external shock and return to a normal state. This is often understood as a socially ‘desirable state’ (Meerow et al. 2016), meaning a movement towards structures that allow for greater environmental protection and social justice (Simmie and Martin 2010; Satterthwaite and Dodman 2013 ​). As Dodman et al (2009:153) recognise, ‘resilience is a process, a way of functioning, that enables not only coping with added shocks and stresses but also addressing the myriad challenges that constrain lives and livelihoods and facilitating more general improvements to the quality of human lives’.

In the light of this discussion, we understand urban resilience (paraphrasing Meerow et al. 2016) as the ability of urban systems and all their socio-ecological and socio-technical constitutive networks, to transform, transit, maintain and bounce back rapidly to desirable functions (socio-economic, political, ecological etc.) in the face of a range of disturbances. Within this understanding, the main objective of urban resilience is to adapt to environmental and climate change, and to transform the systems which limit current and future climate and socioecological adaptive capacities. The ‘transformatory thinking’ that underlies such conceptualisation is certainly related to a non-anthropocentric and strong understanding of sustainability (Neumayer 2003).

2.3. Synergies and tensions between urban sustainability and resilience

The concepts of both sustainability and resilience have emerged in urban research as a way to envisage desirable futures, particularly with regards to a harmonious relationship between urban systems and the natural environment. Yet, sustainability and resilience cannot be used inter-changeably: resilience refers to the adaptive capacities of a given system, with no normative stand on the outcome of such adaptation, while sustainability implies a desirable outcome. Meerow et al. (2016 : 5) correctly point out that ‘depending on how resilience is operationalised, it can lead to spatial and temporal trade-offs and inequitable benefits’. For example, resilience may impede systemic transformation by supporting business as usual (Brown 2012; MacKinnon and Derickson 2012). Tensions may arise in the case of natural systems [Brand and Jax (2007) have argued that a resilient ecosystem is not necessarily sustainable, taking the example of a polluted lake] as well as in social systems [Pizzo (2015) takes the example of criminal organisations, which may be highly resilient, but may not form part of a desirable vision of a sustainable and socially just society].

However, this does not mean that these two concepts cannot be used in conjunction and in a positive way. An understanding of urban resilience as transformatory (that is to say, that urban systems can transform towards more desirable states when adapting to shocks) can be enhanced by a sustainability vision. While resilience focuses on the process of change, meaning how cities evolve and adapt in the face of uncertainty, sustainability thinking prioritises the outcome, offering visions of an ideal future state (Chelleri 2012; Redman 2014) that ought to be environmentally efficient and socially just. As both the process of change and the ideal vision are necessarily context specific, this reinforces our understanding of both urban sustainability and resilience as boundary objects – favouring dialogue and debate rather than serving as universal blueprints for urban development.

3. The need for a holistic understanding of the urban system

Delineating how to move towards more sustainable and resilient settlements is a reflexive and political exercise, not just a procedural or policy issue. This type of understanding, as we see it, defeats the contemporary tendency of focusing more on the process, what we call here ‘urban management’, than on the planning practice itself and its theory. This is not a minor issue. As Neuman (1998) has pointed out, in the face of an increasing complexity of the urban, this tendency has led to a separation of practice and theory, a specialisation of planning and thus a segmentation of the urban in managing sectors. In this way, ‘sectoralisation’ has resulted in the consolidation of a managerial vision that has diluted a comprehensive approach of the urban and thus of the uneven production of urban space and the narratives and forces in play (Smith 1984; Lefebvre 1991; Swyngedou, Heynen and Kaika, 2005; Harvey 2006; Brenner 2014).

Despite the efforts of coordination – some of them indeed valuable – the outcomes of contemporary urban managing have been for the most part constrained (Neuman 1998) as the framing approach is fragmented, contradictory and incapable of taking advantage of potential synergies, constraints that are even more challenging when local capacities are limited.

Achieving urban sustainability and resilience compels transformative thinking and action (Bartlett and Satterthwaite 2016). A conceptualisation of the built environment as a system which comprises multifaceted and interconnected ecological, sociocultural, economic and governance dimensions is therefore required for fully grasping interconnections, synergies, trade-offs, contradictions, tensions and future plausible scenarios or tendencies.

Planning the production of urban space in a changing socioecological and climate context therefore requires a renovated theoretical and conceptual framing for both the planning design and the managing process or, in other words, for urban transformation and transition at multiple spatial and temporal scales. Such a commitment also demands, on the one hand, assessment and monitoring tools, including a set of known and novel quantitative and qualitative indicators, and on the other, an active and combined top-down and bottom-up dynamic planning and decision-making processes across different urban issues, and temporal and spatial scales.

Despite being simplifications of complex phenomena and thus not free of limitations, indicators play a central role in revealing how an urban settlement fares in different fields and according to its specific goals (Rahul. et al. 2013), a task that not only requires but also contributes to (re)defining priorities. They are also useful for sharing best or worst practices among settlements while enabling citizens’ empowerment (Ibid).

Although a diversity of urban indicators and indexes exist, very few transcend the monothematic/sectorial approach by relying on a methodology that departs from a systemic viewpoint of the urban.³ Most of such efforts consider certain dimensions of sustainability and sectorial synergies, reveal material and energy flows and stocks (including ‘urban nexus’) and the opportunities for enhancing urban efficiency, or focus only on certain aspects of sustainability and resilience.⁴

With the idea of transcending linear and fragmented assessments of urban settlements, the ‘pyramid of urban resilience and sustainability’ methodology seeks to offer an ample and multi-criteria framework of analysis, crucial for assembling a range of qualitative and quantitative indicators (the USRI). The idea behind this proposal is to enable a comprehensive view of the urban and thus of an eventual planning approach. Enhancing our understanding of the urban may allow us to imagine comprehensive solutions at multiple spatial and temporal scales, as well as their related transition pathways, including the institutional arrangements needed to support these.

4. Methodology: the pyramid of urban resilience and sustainability, and associated indicators

In order to assess and monitor urban resilience and sustainability, the so-called pyramid of urban resilience and sustainability is composed of (1) dimensions, (2) cross-cutting analytical issues, (3) key elements of analysis and (4) indicators.

The ‘pyramid’ is composed of four dimensions: the ecological or biophysical dimension; the economic or production and consumption dynamics; the sociocultural; and the governance dimension, meaning the political structures and capacities in place. These dimensions seek to be compatible with those of the mainstream conceptualisation of sustainability.

As long as such axes are weak, the so-called pyramid cannot be ‘built’ or may not last in the long run without moving away from its main goals of sustainability, urban resilience and social equity and inclusiveness. As the axes compose a whole unit (a changing and interacting complex system located in a specific biogeographical context), the construction of the pyramid requires a comprehensive planning of the urban, which we have split into two key codependent components: spatial and systemic planning (following Delgado, De Luca and Vazquez, 2015).

On the one hand, spatial planning influences the urban structure (IPCC 2014) and consequently its function, including urban energy and material flows and stocks (Ibid; Litman 2012; Ferrao and Fernandez 2013; UNEP 2013; Delgado Ramos et al. 2015). On the other hand, systemic planning addresses the city as a complex urban system, composed of interrelated and changing economic, political, institutional, technical, sociocultural and ecological networks or subsystems, that extend or interact beyond the urban and its periphery, connecting central cities and their metropolitan areas with rural and urban systems at a regional and global scale. Systemic planning thus transcends the sum of urban networks or subsystems, relying on interdisciplinary and complex-system approaches (Delgado Ramos, 2015b) for novel practices of policy, planning and decision-making, public engagement, and implementation and operation of solutions.

We understand urban systemic planning as a path for an innovative horizontal and vertical integration among traditional sectors, systems, infrastructures and institutional and ‘policy silos’ based on top-down and bottom-up governance schemes. Such an integration, which indeed takes place in concrete territorial spaces, is a means to contribute to (1) a more inclusive, democratic and efficient use of resources and technologies and thus for a better integration of justice criteria into infrastructure and urban design processes and spatial allocation; (2) a greater efficacy of policy implementation, institutional practices, and finance prioritisation and allocation; and (3) a responsible and accountable behaviour of institutions and economic units.

In contrast to systemic planning, the current urban reality is usually characterised by (1) an uneven production of space due to prevailing asymmetric power structures; (2) ambivalent policymaking that, for instance, promotes both low-carbon and high-carbon infrastructure and practices, at times within the same sector; (3) poorly coordinated strategies which are in certain cases exacerbated by the involvement of governments and institutions led by different political parties; (4) overall capital needs and increasing operating costs in a context of limited availability of funding and credit schemes, especially at the local level; (5) top-down decision-making practices – at least regarding key components that shape the urban – and, for the case of the Global South, based on imported solutions that do not correspond to local challenges and opportunities, needs, and sociocultural practices and identities; (6) weak local capacities, including technical and technological ones; and (7) lack of accountability; among other issues that vary from place to place.

Figure 1 describes in detail the general objectives of the ecological dimension of the pyramid, which are pursuing liveable cities, material and energy efficiency, and climate change adaptation and mitigation. We acknowledge that such objectives (and their prioritisation) may vary depending on the case of study to make the methodology more sensitive to particular priorities of different settlements – however, they have been chosen as they appear to be the most relevant to the case of Mexico City (as evidenced by major urban environmental policy documents). The figure does not describe such objectives for the other dimensions as it goes beyond the focus of this paper; yet, we consider that one of the main objectives of the economic dimension is the satisfaction of human needs within natural boundaries, which in turns demands material and energy efficiency in both, relative and absolute terms (degrowth), as well as a more equal distribution of wealth, goods and services (Jackson 2009; Cosme, Santos and O’Neill, 2017; Weiss and Cattaneo 2017); for the sociocultural dimension, advancing human rights and well-being (considering Sen’s capability approach [Sen 1989; 1999]), while taking into account cultural diversity and equity; and for the governance dimension, a participatory and increasingly inclusive and accountable governance system (Patterson et al, 2016).

Figure 1. Pyramid of urban resilience and sustainability.

Source: authors’ own elaboration.

The ecological dimension of the Pyramid articulates ‘key elements’, or themes, for structuring the analysis: (1) habitability, (2) protected areas and green urban spaces, (3) land use, urban structure and form, (4) mobility, (5) climate change and air quality, (6) industry, (7) buildings, (8) energy, (9) water and (10) waste. In addition, cross-cutting issues, such as gender, health and capacity learning and innovation, have been integrated, for merely procedural reasons, in one of the four dimensions of the Pyramid. Themes 1–3 have been aggregated under ‘spatial planning’ component and 4–10 under ‘systemic planning’. As both components constitute what we mean by comprehensive planning, theme 5 could thus be seen as a ‘hinge joint’ that connects and also outlines both, spatial and systemic planning.

Key elements have been selected according to their compatibility with the mainstream climate and urban institutional and policymaking discourse and literature, including that of the IPCC, the UN Sustainable Development Goals, national urban assessments, or the ISO’s Indicators for City Services and Quality of Life, among others. Our purpose here is to reach an ample audience by using a common language while providing, at the same time, a holistic and robust understanding of the urban.

Figure 2 illustrates the holistic assessment which results from aggregating the evaluation of each dimension, considering qualitative and quantitative indicators for each key element of analysis. This systemic approach is a key feature of our analytical framework as it allows to zoom in and zoom out on different dimensions and elements of analysis without missing the complexity of the whole. In this sense, we see USRI as a boundary object (Holden 2013), a methodology to open-up dialogue, build consensus, coproduce knowledge and take decisions across different policy and governance boundaries.

Figure 2. The key elements of the ecological dimension.

Source: authors’ own elaboration.

The proposed key elements of analysis for URSI’s ecological dimension are composed by a set of specific indicators. Figure 3 presents them in detail for Mexico City case. Some key indicators are already being monitored by Federal or local government agencies, or by other type of specialised entities; others are currently not being measured; yet, we believe that they are so crucial that that their regular monitoring ought to be put in place. For those cases, we try to offer a rough estimation when possible.

Figure 3. URSI’s ecological dimension indicators: the case of Mexico City. S

ocial cost of carbon used for estimations was 36 dollars per ton of CO₂e. All data, unless specified otherwise, corresponds to Mexico City.

Source: authors’ own elaboration based on www.ecobici.cdmx.gob.mx; imco.org.mx; www.sedema.cdmx.gob.mx; inegi.org.mx; http://sma.edomex.gob.mx; http://infosiap.siap.gob.mx; www.aep.cdmx.gob.mx/; Programa Nacional de Desarrollo Urbano (http://dof.gob.mx/nota_detalle.php?codigo=5342867&fecha=30/04/2014); Litman, 2012; Suarez and Delgado, 2007; Checa-Artasu, 2016; Delgado, 2012; Delgado, De Luca, Vázquez, 2015; CDMX-INEGI, 2016.

Despite focusing our attention in this paper on the ecological dimension, it is to be clarified that the other three dimensions (economic, social and governance) are equally important for guiding our assessment. In that sense, our empirical analysis includes a quantitative and qualitative contextualisation as well as some indicators or analytics that account for certain core issues related to all four dimensions; yet, we recognise that a similar detailed effort should be carried out for each of the other three dimensions.

In any case, what we seek to transcend is any techno-managerial-fix notion of assessment. With that in mind, we are particularly interested in denoting, in addition to the above said, USRI’s capability to reveal, on one hand, advances or setbacks, and the visions, priorities and social agency behind them, and on the other, current and potential tensions and conflicts that may arise in the process of planning and producing the urban space. As part of focusing on what has been called the ‘governance of indicator systems’ (Holden 2013), we are thus interested in integrating disciplines such as urban political ecology (Swyngedouw et al. 2005; Delgado Ramos et al. 2016) and social ecology (Bruckmeier 2013) to USRI’s methodology.

Ultimately, as Neuman (1998) puts it, comprehensive planning is a focal point of conflict, which in turn is a necessary part of planning and of politics. If plan making, he adds, ‘…is truly pluralist and participative […] then it can build community as it builds upon the social, intellectual, and political capital in a community’. This is, in our perspective, desirable and necessary for moving towards sustainable and resilient cities.

5. Applying USRI’s methodology to Mexico City case: preliminary findings

Mexico City metropolitan area is the largest urban settlement of Mexico and among the top 10 worldwide in terms of population. Its expansion has been dynamic, starting in the 1950s in the central city, and progressively moving towards the periphery. Mexico City’s population went from 3 million inhabitants and an urban land cover of 22,989 ha in 1950 to 8.8 million inhabitants and 61,206 ha in 2010 (Delgado Ramos et al. 2015). The metropolitan area (including Mexico City’s 16 municipalities as well as 59 municipalities of the State of Mexico and 21 of the State of Hidalgo) accounted for 21 million inhabitants and 146,032 urbanised hectares in 2010 (SEDESOL 2012).

The metropolitan area concentrates 17% of the national population, produces 27.2% of the national GDP and generates 18% of total employment; Mexico City accounts for 7%, 16.5% and 8%, respectively. In 2015, Mexico City’s GDP reached 2312,562 million pesos (or about 130 billion dollars, according to the exchange rate of that year), mostly out of commerce and services. Despite being the most relevant economic hub of the country, almost 34.7% of Mexico City’s population is poor and 4.8% extremely poor, mostly located in the periphery; 23.4% of its population does not have access to health services; 52.5% of the population lacks social security and 13% of the population has insufficient access to food (CONEVAL 2012). The prevalence of such shortages is greater in those municipalities with overcrowded, slum-type settlements (more than 300 thousand overcrowded households are officially recognised), where a higher prevalence of poor and marginalised population is recorded (such as Iztapalapa or Gustavo A. Madero). Social perception of public spaces scored 6.5 in 2007, on a scale in which zero means not deteriorated and 10 highly deteriorated (SEDESOL 2010). In such a context, insecurity was and certainly has been since then an increasing concern: in 2013, more than 176 thousand alleged offences and more than 14 thousand allegations of human rights violation were prosecuted in Mexico City alone, and numbers have been climbing since then (CDMX-INEGI 2016). Yet, urban safety policy still does not include a robust perspective on gender, age and poverty issues.

5.1. URSI’s ecological dimension

Preliminary analytics for USRI’s ecological dimension are presented in Figure 3. All data correspond to Mexico City unless otherwise noted.

In relation to data mining and estimation, particular challenges arose from dispersion and inconsistency of data; lack of measurement of certain issues, mainly those related to energy and material urban input-outputs, efficiency use, and material stock and renovation rate; estimation of ecological degradation and climate change impacts, including gender aspects; among others related to urban social conflicts, public participation and empowerment.

In addition, a comprehensive perspective of our case study has allowed us to identify – without being exhaustive – the following key issues that restrain sustainability and resilience, all associated with weak and fragmented planning and managing:

• Despite heavy land-use regulation in the last decades, Mexico City experiences urban sprawl. Real estate speculation, the spread of informal settlements, along with corrupt practices and a lack of coordination between the regulation of urban and protected areas, have meant that most of the population growth takes place in the peri-urban areas of the city, while the city centre stagnates or loses population. This dispersed urban form has consequences for different aspects of sustainability, not least increasing the dependency on motorised transport. Urban growth (formal and informal) also threatens the city’s protected areas, which host most of the ecological services of the city.

• The land on which new settlements are built is not always chosen through planning processes, but through land grabbing and corruption of local authorities; this is a central issue when dealing with risk prevention and reduction, as well as with climate change adaptation. In Mexico City, adaptation and disaster risk reduction actions associated to land use are still not robust enough, despite about two-thirds of its inhabitants being exposed to the effects of extreme climate events (Delgado Ramos et al. 2016). Major efforts centred on preventive actions, including gender considerations, are with no doubt needed.

• Construction has mainly taken place not only in the periphery of the metropolitan area but also in certain parts of the central city which are going through speculation or gentrification processes. In the Cuajimalpa borough, a financial–commercial hub has been developed since the 1990s (on a site that was previously a landfill), along with exclusive residential clusters. Between 2012 and 2016, an expansion of 970 thousand m² of new construction was registered in this area. A similar process is happening in other key areas of the city (e.g. Insurgentes corridor). This intensive vertical and horizontal expansion of the built environment has been questioned by local grassroots movements and some experts, because of the expected pressure on public services and infrastructure, the lack of accountability of the decision-making process and the absence of a parallel strategy for adequate housing provision directed at low-income households. Associated with this, there is no comprehensive plan for sustainable housing. Limited actions have been taken to preserve and upgrade residential buildings despite the existence of local actions for low-income sustainable housing promoted by the city’s Housing Institute. Consequently, sustainable or ‘green’ design and construction is insufficient, spatially fragmented, and usually associated to corporate headquarters new buildings (LEDD certified). Most of other actions focus on implementing low-cost technologies for water efficiency, rainwater harvesting or solar water heating.

• Water infrastructure is inadequate and obsolete, with nearly 41% of drinkable water lost to leakages. The central city alone requires an estimate investment of 4500 million pesos for the next 60 years. Such investments include the replacement of 3100 km of obsolete water pipelines by 2020 (AGU – Agencia de Gestión Urbana de la CDMX 2014), a great opportunity not only to improve its efficiency through optimising the water–energy nexus but also to recover recyclable materials while removing toxic ones such as asbestos and lead that still make up the network. Yet, as far as it is publicly known, such an urban mining strategy has not been developed nor has it been properly integrated with investment plans. Water infrastructure renewal can also be a chance for reducing service inequalities in terms of water provision, water quality and frequency of service, as well as for ensuring fair and equitable water tariffs, a central aspect for ensuring the Human Right to Water and Sanitation.

• Efforts for decarbonising the economy are under way but until now they have been surpassed by growing GHG emissions. Since there is neither formal guidelines for comprehensive climate change action plans at the local level nor mandatory goals (instead those are aspirational goals), each new public administration confronts the issue in a conjectural and fragmented manner; this includes Mexico City despite being at the forefront of local climate action. Sectorial climate change actions do not necessarily enable synergies for climate change adaptation and mitigation at the urban level; moreover, they can be in contradiction with other local sectorial actions (see below). The same is true for the Metropolitan area where, in addition, the different local governments are headed by opposing political parties.

• Actions to transition towards sustainable mobility have been limited and contradictory. The clearest case in point is the expansion of the elevated urban highway system used only by private cars which generates an undesirable infrastructure lock-in, as it promotes the consumption of fossil fuels for decades to come. Another is the loss of urban greenery to make space for private and public transport infrastructure (Bus Rapid Transit and subway systems): from January 2013 to December 2015, more than 10 thousand trees were chopped down in Mexico City because of urban infrastructure expansion (Paz 2015). Therefore, the balance of government policy to foster sustainable and low-carbon mobility from a holistic approach to the urban system is not positive. Although private motorised transportation is responsible for almost half of the central city emissions, most of the actions have focused on public transportation while private transport fleet is insufficiently regulated and its expansion has even been encouraged by environmental and taxing legislation. Opportunities for further improvement include the integration of different modes of transportation, including non-motorised and pedestrian; parking pricing and congestion charge; smart transit technologies; freight transit restrictions at peak hours or during the day; the promotion of more pedestrian-only areas; the regulation of freight transport at the local level; and the restructuration of the urban form to promote mixed land-uses, thus reducing commuting needs. Other type of actions may be needed like new efficiency standards for the auto industry or for fuel production (particularly diesel).

• Air quality, which is related to pollutants emission control, mainly in transport and industry, lacks an integrated and spatial approach and its implementation depends on local enforcement capacities. While air pollution from transport requires, among other issues, higher standards for fuels production (an issue defined at the Federal level), the air pollutants emission control from industry is still not fully enforced at the local level, partly due to the fact that 91% of the industrial units are micro-industries (less than 10 workers each). A deeper analysis is needed to review to what extent the regulation should include some small and micro-industries and how such regulation would take place and be enforced. An analysis of direct and indirect costs, including environmental and health issues, will have to accompany such effort, including considerations related to income, age and gender. Novel governance schemes, along with the implementation of efficient and pollution prevention technologies, seem to be part of the solution; in some cases, relocation of heavily polluting industries, even micro-industries, may be needed and thus some type of compensation schemes would be required, at least for certain cases. A comprehensive metabolic analysis of industry in Mexico City metropolitan area may shed light on this issue, including industrial logistics (distribution hubs, warehouses etc.) within and outside the metropolitan area. This would also support better integrated practices for waste co-managing and recycling.

In the following section, we review in more detail the issue of solid waste as it illustrates the codependencies between urban sustainability and resilience concepts, and the need to think holistically about them in policymaking (a narrow sectorial vision being particularly inadequate to address the socio-political complexity of the waste sector) (Linzner and Ali 2013).

6. A case in depth: Mexico City’s waste governance

It is generally agreed that a sustainable urban system is one that has a circular metabolism; that is to say, one where the material inputs and outputs of a city are reduced, while materials are used and reused in an efficient way within the urban system (Giradet, 2004). This entails matching the waste of some productive processes (whether it is heat, chemical residues, organic refuse) with the input of another, thus reducing both the total waste being produced and the material demand (this is the concept of industrial symbiosis, see Chertow 2008). Planning for the reinsertion of waste materials in productive processes is crucial in terms of reducing the city’s environmental impacts, which is why the USRI includes an indicator of diversion from landfill, which provides an indication of the circulation of materials in the urban system. Yet, this indicator is not sufficient to grasp the interconnections between waste circularity and other aspects of urban sustainability and resilience. In the following paragraphs, we discuss such interconnections by using the USRI framework and identify interdependencies of waste reuse with a range of USRI indicators.

One indicator proposed is the decarbonisation of the economy, which relates to mitigation of climate change. Waste can play a key role in this endeavour, considering that its disposal currently contributes to 14% of the city’s greenhouse gas emissions (SEDEMA 2014). The decomposition of waste in landfills produces methane, which – if not captured – contributes to the greenhouse effect. In addition, the transport of wastes depends on trucks that produce greenhouse gases, and therefore, how far waste travels and, in which trucks, influences the amount of greenhouse gases emissions.

Waste is also related to the indicator of material and energy intensity of the economy: processes of recycling are not neutral, as they are energy and water intensive (although they have, in principle, a lower impact than other waste management practices; see for instance Chen and Lin 2008; or Craighill and Powell 1996). Diverting waste from landfill by increasing recycling rates will therefore not only improve the city’s performance in terms of the environmental impacts of waste disposal, it will also most likely worsen it in terms of energy and water use – a clear example of a tension between sustainability objectives. There are also opportunities associated with waste recovery, such as the capture of methane for electricity. In Mexico, methane capture potential has been estimated at 40 million tons of CO₂ in 2000 (Delgado Ramos et al. 2015), but it has not yet been implemented in Mexico City or its metropolitan area.

Waste is also relevant in terms of vulnerabilities and disaster risk prevention, reduction and preparedness, not only because improper disposal of waste can contribute to flooding, but also in terms of water quality. The decomposition of waste produces toxic leachates, which penetrate the soil and the groundwater stocks if not properly managed. This threatens the availability of clean water for agriculture and drinking, which are key aspects of reducing vulnerabilities of local communities, and of their resilience. In turn, this affects the ‘urban–rural nexus (dependencies, viability and sustainability)’: by disposing of their waste in their rural hinterland, cities externalise their environmental hazards to surrounding rural areas, which threatens the latter’s sustainability. The case of water contamination through leachates is a clear example of the transfer of environmental hazards from urban to peri-urban areas, which poses a question of environmental justice (where the environmental health of urban dwellers is gained at the expanse of their rural counterparts’ resilience).

Although traditionally thought of as an environmental problem, waste affects urban sustainability and resilience through its social, economic and governance dimensions as well. In terms of the urban economy, a well-planned waste strategy has the potential to influence the dynamism and innovation capacities of the industrial and services sectors. In addition, waste recovery could contribute to improving municipal financing capacity (‘capturing local value’) which is a crucial aspect of the economic sustainability of the city, in addition to building up financial resources of the local government, which is critical for good governance.

Yet, good governance goes beyond improving the finances of municipalities: it can be defined as ‘characterised by inclusion and representation of all groups in urban society; accountability, integrity and transparency of local government actions; a capacity to fulfil public responsibilities, with knowledge, skills, resources, and procedures that draw on partnerships’ [World Bank, 2000 : 49; cited in Michelutti and Smith (2014)]. Thus, looking at the case of waste, an important aspect of good governance is the capacity of the local government to work with a diversity of waste handlers operating in networks (some being municipal employees, others working in the private sector, and others being independent – or informal – workers) in order to govern in an efficient and accountable way.

Finally, waste recovery is related to social sustainability through waste handlers’ working conditions (and particularly the risks to their physical and mental health), as well as more generally through the education and involvement of citizens around issues of waste management.

We now use the USRI to assess the case of waste governance in Mexico City. In Mexico City, 12,957 t of waste is produced each day (this excludes industrial waste), out of which approximately 42% is diverted from landfill (SEDEMA 2015) (see Figure 4). This number is made up of 13% of composting, 1% of formal recycling (flows reaching the ‘recycling industry’ in the diagram) and 28% of informal recycling⁵ (flows reaching the ‘recycling traders’ in the diagram).

Figure 4. Mexico City’s waste flows diagram.

Source:  authors’ elaboration, based on SEDEMA, 2015 and own primary data collection

Indeed, there is a vibrant activity of ‘pepena’, or informal waste-picking, in Mexico, providing a livelihood to many households. This informal waste handling (lower box in the diagram) is responsible for over half of the city’s rate of diversion from landfill.⁶ It is a self-organising activity, where the waste handlers find out which materials have a market value (mainly paper and cardboard, plastics and metals – iron, copper, tin, aluminium, steel, bronze, silver, gold). Through a range of intermediaries (waste pickers, small recycling centres, recycling industry), the materials are separated, processed, accumulated, compacted and transported to the industries that require them as inputs (Guibrunet et al. 2016). The fact that this activity takes place informally is not coincidental: currently, the government does not have the capacity to separate and process these recyclables (to take an example, at the government-run waste selection plant, recyclables are exclusively extracted and sold by informal workers). This scheme is also cheaper as informal work relies heavily on (low-paid) labour rather than capital.

There is a wide range of legal documents governing waste management in Mexico, and in Mexico City particularly.⁷ The main plan defining strategies for urban waste management is the Mexico City’s Programme for the Integral Management of Solid Waste (GDF, 2010). It is composed of a diagnostic of waste generation and composition as well as some principles and guidelines about waste management. The main focus of the programme is the improved management of organic waste through composting (achieved by creating composting infrastructures, and promoting organic waste separation in the household). The programme also proposes stronger environmental regulations and pollution control and highlights the need for stronger inter-institutional cooperation. However, issues of environmental justice appear to be overlooked: Figure 5 shows how the waste disposal infrastructure, which causes environmental health hazards (particularly the contamination of groundwater through leachates), is located in the neighbouring States of Mexico and Morelos.

Figure 5. Map of waste infrastructure and illegal dumping sites serving Mexico City. Source: authors’ elaboration based on PAOT (2010) and SEDEMA (2015) and personal observations.

In addition, the strategies proposed are sectorial and do not tap into the positive synergies existing between efficient waste governance, reduction in material requirements, social justice and local economic development and dynamism. For instance, informal waste handling is absent from the diagnostics and strategies – this means that the dynamism of informal workers, as well as their local and technical expertise, is overlooked.⁸ This is problematic, as it impedes the possibility to improve the waste recovery system by ‘building on existing strengths’ (Wilson et al. 2012), recognising the role of informal actors in waste governance and integrating them into a sustainable waste co-management system (Scheinberg and Anschütz 2006; Wilson et al. 2009; Linzner and Ali 2013; Vergara et al. 2015).

This section shows that the USRI framework can be used to analyse the case of waste in a holistic way, pointing to potential synergies and tensions between objectives of diversion from landfill, climate mitigation, local economic development, poverty alleviation, and social justice across multiple spatial and time scales.

7. Conclusions

The framework presented in this paper explores the potential of a systemic approach to understand complex urban change towards or away from sustainability and resilience. Traditional, sectorial and quantitative data are still central for this assessment (because of the predominance of such datasets); however, complementary quantitative and qualitative indicators are needed to better identify interconnections, dependencies, trade-offs, co-benefits, barriers or lack of knowledge, and considerations of good governance, capacity building and socio-environmental justice, including gender inequalities. Analytical perspectives and tools, emanating from industrial ecology, ecological economics, urban political economy, urban sociology, urban political ecology or discourse analysis, are thus to be considered to enrich the assessment and the proposals it may encourage.

The holistic character of the USRI methodology lies in its interdisciplinary integrative framework and its capacity to manage, organise and harmonise, in a transparent manner, large quantitative and qualitative data sets (representing both, ‘strong’ and ‘soft’ values). This allows, first, a better assessment of the current state of an urban settlement as a whole – and its interactions across multiple spatial scales. In addition, it can be used to identify opportunities through time and space scales, such as the improved management of resources and infrastructure or the better coordination of policy and institutional practices. In that sense, our ‘key elements of analysis’ should not be seen as traditional sectors of management but rather as key interconnected components of the urban system where not only biophysical and economic dynamics occur, but also where socio-political relationships, tensions, interconnections and arrangements take place. Indeed, the case of waste shows that the ‘key elements of analysis’ are just a starting point for an analysis which must focus as much on the interconnections between those elements, as on the elements themselves.

The overall purpose of developing the USRI is to gain a better understanding of the city and its relation to environmental change. In order to do so, the data inputted in the USRI have to incorporate both, top-down and bottom-up approaches, as well as the coproduction of knowledge between experts and non-experts and grassroots movements (Delgado Ramos 2015b). The production of such knowledge is necessary to promote good practice and accountability within planning processes, namely looking beyond sectorial silos and approaching policy with a holistic view of the urban system. Boyd and Juhola (2015) suggest that knowledge-building is a crucial aspect of an adaptive governance system: as climate change affects cities and their environmental, social and economic processes, adaptive governance is one that functions in conditions of uncertainty and non-linear change and is essential to build urban resilience. To this end, academia as well as public and private institutions need to evolve, particularly in how they frame, produce and use knowledge, not only for understanding urban dynamics but also to test, monitor and evaluate the impact of urban strategies (Boyd and Juhola 2015:1242). In other words, encouraging transformatory thinking goes hand in hand with building a transformatory assessment framework which includes novel tools of analysis, data generation, and cross-fertilisation of ideas and decision-making (e.g. intersection of big data, analytics and GIS; social-multicriteria evaluation; novel schemes of coproduction of knowledge etc.). As the pyramid of resilience and sustainability and its associated assessment and monitoring tool (the USRI) are tested in other cases, we expect that they will contribute to this endeavour.

The proposal, however, has its own limitations. Being a complex approach, data collection at the local level is one of the main challenges, particularly for cities in the Global South. Processing, modelling and interpreting large datasets and values, including aggregating and weighting of data, are challenging and not free of uncertainties and reflexive choices. In addition, there are limited efforts towards the coproduction of knowledge and the incorporation of bottom-up participatory processes, which often leads to the prevalence of linear analytical approaches and decision-making.

One conceptual limitation concerns the monitoring of urban resilience: the USRI focuses on assessing cities’ progress (or backlog) towards a sustainable state (the desirable outcome of an urban transition). The resilience of cities, which is arguably built through the process of transition itself, is not actually measured through USRI’s indicators (but it may be achievable once the literature offers a more robust understanding on how to measure urban resilience).

Finally, even though the USRI provides a robust framework in order to approach urban sustainability and resilience, findings and conclusions still need to be cautiously translated into fair and inclusive policies at multiple spatial and temporal scales. This relates both to the translation aspect itself and to the political acceptability and practical implementation, the latter being particularly difficult in Mexico City due to the existing socio-political and institutional context. A transformatory process of the institutional culture, practice and receptiveness will be necessary to enhance USRI’s feasibility.

Acknowledgements

Part of this paper is an outcome of Delgado’s sabbatical research project on ‘Challenges and Opportunities for the Transformation to Sustainable and Resilient Urban Settlements’ supported by the Interdisciplinary Research Center on Sciences and Humanities of the National Autonomous University of Mexico (CEIICH-UNAM) and UNAM's PASPA-DGAPA program. The research project has been hosted by the University of California Santa Barbara (visiting research scholar) and the California Energy Commission (volunteer).. Another part of the paper corresponds to Guibrunet’s PhD field research carried out with the technical support of CEIICH-UNAM and a fellowship of the UCL ISR PhD programme on the Sustainable Use of Resources and the Environment. .

Disclosure statement

No potential conflict of interest was reported by the authors.​

Additional information

Funding

This work was supported by the PASPA – Dirección General de Asuntos del Personal Académico of the National Autonomous University of Mexico.

Notes on contributors

Gian Carlo Delgado-Ramos

Gian Carlo Delgado-Ramos is a full-time researcher at the Interdisciplinary Research Center on Sciences and Humanities, National Autonomous University of Mexico (UNAM), member, level II, of the Mexican National Council for Science and Technology (CONACYT). He received the 2014 Research Award from the Mexican Academy of Sciences for his work in Social Sciences Research. He was a lead author of the 5th Assessment Report of the IPCC (working Group III, Chapter 12).

Louise Guibrunet

Louise Guibrunet is a PhD student at the Institute for Sustainable Resources, University College London (United Kingdom), hosted at the Interdisciplinary Research Center on Sciences and Humanities (UNAM) for a research stay between September 2015 and June 2016.

Notes

1. ‘Slum’ is defined, in the Millennium Development Goals, as a housing type which cumulates several of the following: lack of piped water, lack of sanitation, overcrowding and non-durable housing. See, www.un.org/millenniumgoals/environ.shtml.

2. Goal No. 11, see, http://sustainabledevelopment.un.org.

3. Hiremath et al. (2013) support this appraisal when they state that ‘most currently available urban assessment methods fail to demonstrate sufficient understanding of the interrelations and interdependencies of social, economic and environmental considerations’.

4. Some examples of indicators and indexes that offer a more complex approach of the urban than traditional ones are the 100 Resilient Cities Index pioneered by the Rockefeller Foundation (www.100resilientcities.org); the Resilience Capacity Index of the University of California – Berkeley (http://brr.berkeley.edu/rci); the SDG Goal 11 Monitoring Framework (UNHABITAT 2016b); the so-called tree analysis of urban resource consumption (Saldivar-Sali 2010); the Global Climate Risk Index of German Watch (http://germanwatch.org/en/cri) or the Notre Dame Global Adaptation Index (http://index.gain.org). Literature on ‘urban nexus’ includes studies on water–energy–carbon nexus (Howells et al. 2013; Nair et al. 2014); energy–water–food security nexus (FAO 2014); among other. ICLEI-GIZ-BMZ (2014) has made a review on different practical ‘nexus’ cases.

5. By informal waste handling generally (and recycling in particular), we mean those activities which are not regulated, controlled or monitored by any instance of government. This is in opposition to formal waste management activities carried out by government employees (such as garbage collectors) or private companies duly registered with the Ministry of the Environment.

6. We estimate this to be a conservative figure, considering that it does not include the waste collected during waste-picking activities outside governmental infrastructure (shown are ‘waste-picking at home’ and ‘waste-picking in the street’ in Figure 4).

7. The main ones are, at the national level, the General Law for Waste Prevention and Integral Management, as well as the Ministry of the Environment’s norms regulating waste management practices. At the urban level, the Law of Solid Waste (2003) is the document which sets the rules for urban waste governance, and particularly, the annual generation of a waste inventory and the periodic production of a Program for Integral Management of Solid Waste. Indirectly, the different climate documents (Law of Climate Change Mitigation, Adaptation and Sustainable Development, and the Climate Action Plan) also influence the waste strategy.

8. The main strategy to increase recycling is based on punctual government-run recycling schemes – such as running recycling barter events, or installing containers for old batteries and electronic waste (see SEDEMA 2015) – which currently represents 0.04% diversion from landfill (5 t/day, see Figure 5).