John E. Fernández

Typological Metabolism of Urban Transitions

Vernacular habitat © Creative Commons

To understand the mutations of global urbanization, one must take into account the local singularities of every urban situation. A new categorization of cities is more necessary than ever, and technology, including digital technology, is proving to be an essential tool. In this context, Professor John E. Fernández presents the work of MIT’s Urban Metabolism Group, whose complex studies use big data in order to draft a set of urban types categorized according to their metabolism. Resource use and waste production are just some of the metrics they employ in the design of carefully-targeted and efficient sustainability strategies.

John E. Fernández is an urban planner and architect. He teaches in the architecture department’s Building Technology Program at MIT.

The text of cities has so often held a certain unique poignancy; a mix of personal and collective sentiment and the sweet reach for an urban romance. This sentiment is only heightened by the fear embedded in urban chaos and system unpredictability: the uncontrolled oscillation of complex behavior set in motion by the collective desires and actions of millions of souls. Even sober and deeply accomplished academic writing on the subject of cities, and especially on the future of our urban world (see Glaeser 2011, for example) is a blend of dark and luminescent neo-promotional prose that harkens back to the quaintly optimistic literature about the early days of the industrial revolution.


Notice different urban metabolisms

This kind of writing, while so dear to my own heart, has the tendency to maroon us on particularly beautiful intellectual islands from which it is difficult to navigate. Envisioning new technical-social arrangements sometimes clashes with visions that spring ready-made from our sentimental mind’s eye. For some time now we have been offered up a seemingly endless series of positivist images of the urban future, whether we find their origins from large international architecture and engineering consulting firms or from the fevered speculation of tenure track professors picking up the sci-fi wave of high-tech green as new paradigm, or alibi. The overwhelming tone of these images is their generic quality, their strong similarity to one another whether it be future Singapore or New York City, Hamburg, Masdar, or numerous eco-cities proposed and labeled around the world. A picture is worth a thousand words, but the imagery of green cities is the same generic thousand-word message over and over again.

Consider that today one would not think of sustainable, resource-efficient buildings in a generic sense. Anyone associated with efforts to move toward net zero energy and serious materials reuse and recycling understands the significant differences between buildings that accommodate vastly different types of human activities. In fact, today we know that it is extremely important to distinguish between the many types of buildings and their accompanying energy and material requirements; laboratories, hospitals, retail malls, warehouses, car garages, and the like, when considering design, technology and other strategies for a sustainable built environment.

So, when we speak of “cities” generically, are we speaking with any authority, or does this discourse reflect an immaturity and naïveté born of an arrogance of assumed yet critically incomplete understanding?

"Figure 1 : Mumbai "© John E. Fernández
"Figure 1 : Singapore" © John E. Fernández


Figure 1

Caption: Singapore and Mumbai. When considering urban sustainability is it reasonable to think that Singapore and Mumbai can be considered in the same, or even in a remotely similar way?

These thoughts spawned the motivation behind research to uncover useful differences among many thousands of cities; a search for distinctions and possible classifications that forms the core of this article. Closely associated with the motivation to discover species and subspecies of urban resource consumption among the range of agglomeration economies is the idea that city types as they exist today may be telling us more about the evolution of cities than we currently appreciate.

Figure 2 : 

Caption: Two graphic representations of city resource consumption types showing an energy-intensive city on the left and a material-intensive city on the right (Bio, biomass; FF, fossil fuels; TE, total energy; EL, electricity; CO2, carbon dioxide emissions; Ind, industrial minerals; TM, total materials; Con, construction minerals).

The Urban Metabolism Group at MIT has analyzed hundreds of cities for the purpose of deriving the above-mentioned city typology. This typology is based on urban resource consumption (UNEP 2013).

« Figure 2 » © John E. Fernández

The Urban Metabolism Group at MIT has analyzed hundreds of cities for the purpose of deriving the above-mentioned city typology. This typology is based on urban resource consumption (UNEP 2013).

Figure 3

Caption: City typology using the graphing technique explained in Figure 2.

Starting at the upper left-hand corner and moving to the right in Figure 3, then proceeding to the next row, each city type is briefly described and a few representative cities are listed.

Figure 3, Types 1-5 © John E. Fernández

Upper Row (Types 1–5, left to right)

Type 1 cities have low levels of resource consumption in all eight categories, except for water, which is found to be low to medium (India, Kolkata and Naihati; Indonesia, Jakarta and Surbaya; Cambodia, Phnom Penh; DRC, Kinshasa; Sierra Leone, Freetown). Type 2 cities also have low levels of resource consumption in all eight categories, except for biomass, which is found to be medium indicating the dominance of an agricultural economy (Nigeria, Lagos; Ethiopia, Addis Ababa; Senegal, Dakar; Guatemala, Guatemala City; Mali, Bamako; Kenya, Nairobi; India, Mumbai; Ecuador, Quito; Myanmar, Yangon). Type 3, a combination of low and medium resource intensity; low consumption of total energy, electricity, fossil fuels, and industrial minerals. Emission of carbon dioxide is also low; cities in South America, Asia, and Africa. Type 4 shows total energy, fossil fuel, and electricity consumption are low as is carbon dioxide emissions. Urban economies within this type are found in developing countries fueled by significant biomass-based industries. Type 5 cities have low carbon emissions while total energy, fossil fuels, electricity, industrial minerals and ores, and construction minerals display a low to medium level and biomass and total material consumption are high. (Uruguay, Montevideo; South Africa, Durban; Brazil, Curitiba).

"Figure 3, Types 6-10" © John E. Fernández

Middle Row (Types 6–10, left to right)

Total energy, fossil fuels, electricity, material consumption, construction minerals, industrial minerals and ores are all low for Type 6 cities showing evidence of early stages of industrialization based on carbon-rich energy fueled by coal and oil (India, Delhi, Bangalore, Hyderabad, and Chennai; Vietnam, Ho Chi Minh City; Egypt, Cairo). Type 7 cities consume biomass and total energy at low levels, fossil fuels at a medium level, emit carbon dioxide at a medium level, and consume industrial minerals and ores, construction minerals, and total materials at high levels. This is the only type that is comprised of cities in one country: Japan. Electricity consumption is low and everything else jumps to medium for Type 8 (China, Beijing and Shenzhen; Brazil, Brasília; Mexico, Mexico City; Turkey, Istanbul). In Type 9 only industrial minerals and ores are at a low level of consumption and every other resource is medium or medium-high (Serbia, Belgrade; Libya, Tripoli; Argentina, Buenos Aires; Iran, Tehran; Portugal, Lisbon). Type 10 cities consume energy, construction minerals, and emit carbon at the medium level. Industrial minerals and ores, total materials, and water are found at medium to high levels. Type 10 cities are found in developed countries with diverse and industrialized national economies (UK, London; Germany, Berlin; Ireland, Dublin; Italy, Rome and Milan; Spain, Madrid and Barcelona).

"Figure 3, types 11-15" © John E. Fernández

Lower row (Types 11–15, left to right)

In Type 11 medium consumption is observed for carbon and industrial minerals and ores, medium to high for water, biomass, total energy, and fossil fuels, and high for electricity, total materials, and construction minerals (France, Paris; UAE, Dubai). Type 12 cities consume total materials, biomass, and construction at a low-medium level, total energy, electricity, fossil fuels, and industrial minerals and ores at a medium level, and carbon dioxide at a high level (China, Shanghai; Israel, Tel Aviv; Russia, St. Petersburg). The lowest level of consumption, at medium, is with industrial minerals and ores and the highest are at a high level for both total materials and carbon emissions in Type 13 (USA, New York, Los Angeles, and Seattle; Finland, Helsinki; Denmark, Copenhagen). Industrial minerals and biomass are consumed at low levels in Type 14. Then there is a jump to medium-high with total materials, water, and construction minerals and high for all energy components as well as carbon dioxide. Cities with this particular urban metabolism profile are all found in petroleum-producing nations of the Middle East (Saudi Arabia, Riyadh; UAE, Abu Dhabi; Kuwait, Kuwait City; Qatar, Doha). Finally at the extreme end of the spectrum for urban resource intensity, all eight resources are consumed at high levels, as is the emission of carbon dioxide in Type 15. These cities are high consumers for all of the obvious reasons; low densities thereby requiring significant energy expenditures by automobile, high affluence, and challenging climates requiring significant building heating and cooling energy expenditures (USA, Phoenix and Chicago; Canada, Toronto and Montreal; Australia, Sydney and Melbourne).

The typology reveals many traits of city metabolisms directly, as listed above. It also begins to imply and sometimes partially uncover indirect and associated attributes that cannot be reasonably ignored and it illustrates an enormous range of urban resource consumption. Lower tier cities do not come anywhere near metabolizing materials, energy, and water at the same rate or overall volume as those in upper tiers. These differences are not constrained by or defined primarily by national borders or distinct regions, though there is certainly a segregation of types between the developed north and the developing global south (Fernández 2014).

In addition, a certain segregation can be seen in terms of climate though a stronger correlative factor is the type of economy and the value of the national production on the world stage. Cities in financial powerhouses and high technology regions clearly rank as most intense in their overall resource consumption though less intense in industrial materials, reflecting the material-lean nature of these economic activities. The high overall resource consumption of these kinds of cities is again a reflection of the resource consequences of wealth creation and unconstrained and even profligate consumption (as in Singapore).

The typology presents intriguing evidence, albeit broadly delineated and requiring more investigation, of strong cultural factors and forcing. Take for example the Japanese cities and their steadfast residence in a single type of city that does not exist in any other country. Any good explanation for this extraordinary exceptionalism must include cultural considerations; frugality, muted individual consumption, collective allegiance, or whatever. This paper does not pretend to even begin uncovering—much less explaining—the cultural forces that contribute to the clustering of cities into one type or another. However, the typology does indicate that we should make an effort to consider how cultural factors play a role in influencing the resource consumption of urban economies.

Trajectories of cities’ evolution

There is another important aspect of the typology; the notion of types as states. In other words, the types that have been proposed here should be seen as static snapshots along a dynamic continuum; representatives of a set of particular situations along a temporal path. These paths may be populated by any number of the types that have been found in our study leading to the possibility that, with further study, one could delineate the transformation, or evolution of one state into another.

For example, a transformation that is so commonly cited that by now it has achieved fetish status for the sustainable future cognoscenti is the urban transformation from dirty, sooty, industrial to clean, healthy, and service-driven. The popular press and the design world is now saturated with the rhetoric and sexy imagery of the coming new age of urban heaven populated by well-adjusted, well-educated, environmentally conscious adults whose children are all above average. Unfortunately, this world is real for a paper-thin slice of the world’s population. For many urban residents the city will continue to be dirty, sooty, and if not directly industrial, far from a post-industrial reality.

However, transformations do occur. Just as national economies evolve, develop, and transform, the cities contained within them also change, adjust, and transform in a variety of ways. The typology described above suggests numerous pathways, intended and unintended, expected and unexpected. As stated before, more work is required to tease out actual historic pathways and reliably forecast that which will define our urban future (Ferrão and Fernández 2014). This work is important.

Recall again the fact that the vast majority of the global increase in urban population in the coming decades will occur in the developing world and that this increase will proceed at an unprecedented rate. There is no question that the intensity of this urbanization means that a great many new urban residents will continue to live in poverty, and therefore, well below per capita consumption levels to be found in many cities of the developed north. However, cities create wealth. Despite their poverty, these residents will still be wealthier, and therefore possess greater potential to consume, than their agricultural brothers and sisters. This is the reason people go to the city and send money to their families in the countryside. They earn more, consume more, and contribute to resource consumption at greater rates.

Returning to the typology, it is clear that we are entering a period in which an enormous transformation is taking place, not toward greater global sustainability but toward greater resource consumption; that is toward less, or a less likely sustainable future. Urbanization will not act to reduce consumption but it will be one of the major forces driving it upwards. The vast increases in population to the cities of the lower tier (the upper row in Figure 3) will push material, energy, and water demands skyward while emitting carbon into the atmosphere toward the dreaded 500 parts per million by 2100, or sooner.

Furthermore, contrary to the great bulk of published and spoken wisdom on this subject this is as it should be. Urban populations need to consume more if we are to create a humane urban future. The cities of the lower tier are not a future we should aspire to. The world should become less sustainable before it directs itself toward the difficult task of global sustainability.

So designers let go of your sentimental versions of green and embrace the numbers that show we are headed toward a sobering and complicated urban future. Doing the right thing will require, for the foreseeable future, an increase in the resource intensity of the world’s urban population. Of course, you could conclude the opposite and believe that the only right thing to do is to advocate for resource efficiency in light of the serious global consequences ahead. However, this author strongly believes that, were you to do so, you would still be faced with the inexorable tidal wave of desire that will drive billions of new urban residents to acquire air conditioning, discover modern appliances, and eat more and more meat, and generally consume as much as they can afford.

(This article was published in Stream 03 in 2014.)



Fernández, J., “Urban Metabolism of the Global South”, In: S. Parnell and S. Oldfield (eds.) A Routledge Handbook on Cities of the Global South. (London: Routledge, 2014).

Ferrão, P. and Fernández, J., Sustainable Urban Metabolism. (Cambridge: MIT Press, 2014).

Glaeser, E. L., Triumph of the City: How our greatest invention makes us richer, smarter, greener, healthier, and happier. (New York: Penguin Press, 2011).

United Nations Environmental Program. City-Level Decoupling: Urban resource flows and the governance of infrastructure transitions.  (New York: 38-43, 2013). Available at: Laste accessed 5 October 2014.