In This Issue
Earth Systems Engineering
March 1, 2001 Volume 31 Issue 1

Rethinking Urbanization

Thursday, March 1, 2001

Author: George Bugliarello

Balancing the biological, social, and machine elements of modern cities will be key to creating environmentally sustainable, emotionally satisfying urban centers of the future.

Since the emergence of the first concentrated human habitats some 10,000 years ago, urbanization has increased vertiginously. In some of its larger manifestations such as the very large cities we call megacities-currently defined by the United Nations as having more than 10 million inhabitants-urbanization has become particularly important in the developing world (Bugliarello, 1999). Even if there are ambiguities as to what exactly constitutes a city or an urban area, rapidly growing urbanization is a new and seemingly uncontrollable phenomenon.

At the beginning of the 20th century, only about 5 percent of the world population lived in urban areas. Today, that figure is 40 percent and is projected to grow to 60 percent in the next 20 years. In the United States, urban living is even more prevalent. Projecting into the year 2030, all of the world’s population growth will be in urban areas. Over the next 30 years, urban population will increase from 2.9 billion to 4.9 billion people, mostly concentrated in developing nations. The largest population growth will occur in Asia, but Africa will have the higher rate of growth. The number of cities with 5 million inhabitants will increase from 41 to 59, and the number of cities with 10 million people will climb from 19 to 23 (Brennan-Galvin, 2000).

Urbanization is the most powerful and most visible anthropogenic force on Earth. It affects the surface of the Earth, its atmosphere, and its seas. The expanding surface that cities occupy and the resources required to supply their needs absorb or transform, directly or indirectly, ever-larger extensions of forests and arable land. In the developed world, those extensions may be hundreds of times larger than the surface of a city and consume material and energy resources at rates per inhabitant an order of magnitude greater than those of cities in the developing world. The problems of atmospheric pollution are exacerbated in cities that are virtually devoid of oxygen-generating vegetation. The surface “footprint” of a typical city consists predominately of buildings and concrete or asphalt, which repel water and can lead to deprivation and even subsidence of aquifers. Aquifers under Mexico City, for example, have dropped some nine meters since the beginning of the last century (Rowland, 2000).

Substantial cities began to emerge perhaps 5,000 years ago and, on a greater scale, with cities like Memphis, Babylon, Athens, Beijing, and Rome, in the last three millennia. In the vast period between the growth of agriculture and the Industrial Revolution, most innovations occurred primarily in the social domain-codified laws, organized armies, bureaucracies-but there emerged also some crucial new technologies for the city like aqueducts, bridges, and fortifications.

After the Industrial Revolution, the waves of technological inventions and innovation that succeeded each other with increasing rapidity made the city what it is today. Industrial manufacturing attracted armies of workers to the cities; railroads, and later airports, weakened the commercial advantage of maritime cities; the internal combustion engine helped create the suburbs; electricity made possible all sorts of labor-saving devices; the elevator permitted the vertical city; sanitation made cities healthy; radio, later complemented by computers and the Internet, allowed people to interact without being physically in contact and to work cooperatively at a distance (Moss, 1998). Biotechnology and bio-machines, now emerging, will affect the city in ways we cannot still fully fathom.

The interval between these major innovations has shrunk. If more than 100 years separated the Industrial Revolution from the internal combustion engine, only 50 years separated the computer from the radio, and about 30 years biotechnology from the computer. These innovations have added to the fascination and the promise, whether realistic or not, that the city offers to people from the rural areas, and they have fueled the still unabated growth of most urban concentrations. No matter how undesirable and ultimately unsustainable this may be, there seem to be today, thanks to technology, virtually no limits to the growth of cities based on availability of land or adequacy of critical resources (Groat, 2000).

Many Cities Dysfunctional
Today’s cities are essential instruments of social advancement, wealth creation, globalization, creativity, psychic energy, and birth-rate reduction. But many of today’s cities also are dysfunctional. They are large consumers of resources, harbors of poverty, and concentrated sources of pollution. They are congested and, in the rapidly growing megacities of the developing world, bursting at the seams. They are difficult to manage, particularly where lack of resources compounds the problem. And they pose risks to their inhabitants.

Cities affect their environment by drawing resources-materials, air, water, energy-from increasingly long distances (the resource “footprint”). Their products tend to be distributed worldwide and become sources of pollution elsewhere. The city-genic pollution on the ground may be limited to a few hundred miles, but air pollution may circle the globe. Cities affect their environment regionally because of the growing surface over which they extend, the intense use of their hinterland, and, with maritime and riparian cities, their encroachment on coastlines.

Pollution in large urban aggregates is aggravated by the traffic caused by the separation of residence and place of work, and by the increasing use of heating and air conditioning. The concentrated nature of the city reduces the space available to its occupants in their dwellings, denying them the less-polluting remedies such as higher ceilings or shading by trees available in less-dense habitats. The growth of poverty, particularly in cities of the developing world, is a most disturbing trend associated with urbanization. Poverty adds to the dysfunctionality of a city and often contributes to urban sprawl by encouraging the flight of the more affluent from the city core.

The risks associated with urbanization are due to natural hazards, anthropogenic causes, or a mixture of the two. Natural hazards, from earthquakes and floods to volcanoes and diseases such as malaria, are made more dangerous by heedless expansion in areas exposed to such risks. Anthropogenic risks include accidents, war, terrorism, crime, changes in the economy, and lifestyle diseases such as depression, bronchitis and emphysema, tuberculosis, and AIDS.

Congestion, such as overcrowded roadways and air traffic delays at major airports (estimated several years ago to cost some $5 billion annually [Craig, 1988]), is one of the most immediately evident and ubiquitous signs of urban dysfunctionality-whether in developed or in developing countries-and so are slums. Another sign of dysfunctionality is the difficulty most large cities have disposing of their solid waste. This is an issue that offers the possibility of many creative solutions but which generally remains, particularly in the developing world, one of the most intractable problems. More subtle signs of dysfunctionality are urban sprawl, the monotony of the grid pattern of streets, and the monocultural zones devoted exclusively to one set of activities, such as malls or financial districts, which become deserted when those activities end.

A problem common to all but the most affluent of today’s cities is that many elements of their infrastructure have not been extended or improved since originally built. Railroads, bridges, sewers, water mains, major roads, and buildings have not been able to keep up with the expansion of many cities because of the speed of that expansion and because of cost.

If we are to make urbanization environmentally and socially sustainable, the great challenge is to rethink the city. The design of the city of the future has been for a long time a passionate battle point of utopias, ideologies, theories, and experimentations. Leonardo da Vinci’s separation on two levels of pedestrian and vehicular traffic (Figure 1) and, a century ago, the garden city (Perry, 1929; Relph, 1987) exemplify concepts that continue to make sense today. Many other concepts have not stood the test of time.

Regardless of ideology, few would disagree that there are certain pragmatic imperatives to which the city of the future, whether in America or elsewhere, must respond. It must reduce hazards to its inhabitants, improve livability, and be sustainable, that is, capable of existing indefinitely in time without doing irreparable damage to the environment. A city is an extremely complex organism; its future forms cannot be projected or prescribed. There are, however, some essential characteristics the city needs if it is to respond to the imperatives.

The city of tomorrow must be caring and emotionally satisfying; it needs to be ecological, intelligent, manageable. These characteristics must interact synergistically in response to the imperatives. Thus, to improve livability, the city must be caring and emotionally satisfying. This, in turn, implies a city that is intelligent, manageable, and ecological. To be sustainable, the city must be ecological. To reduce hazards to its inhabitants, it needs, again, to be intelligent and manageable. Elimination of slums requires the synergy of the “city efficient,” the “city manageable,” and the “city caring and emotionally satisfying.” Similarly, reduction of consumption requires the synergy of the city efficient and the city manageable. These synergies are not easy to achieve but are mandatory if the dysfunctionalities of today’s cities are to be remedied.

The city caring and emotionally satisfying is one that provides jobs, housing, health, and education, gives its citizens a sense of protection, and sees the urgency of solving the problem of poverty. Poverty threatens the city’s physical and emotional health, and its elimination is viewed by some as a key to any hope of improving sustainability (Perlman, 2000). But this is not enough. A sense of belonging, a sense of pride, and a sense of adventure are also essential ingredients of the city caring and emotionally satisfying. Contributing to them are stability (not the constant tearing down and reconstruction that makes today’s city a palimpsest), aesthetics, and good management-the city not only functional but beautiful. A sense of adventure militates against grid layouts that we inherited from the ancient Greeks and Romans, and against the extreme segregation of functions in separate quarters of the city-for example, the impersonal gleaming towers of the business district that leave no room for diverse, smaller-scale activities.

If the city of the future is not to do irreparable ecological damage and is to be sustainable, it must contain or reduce its geographical and resource footprints. The area occupied by the city and the tributary territory necessary to feed and otherwise support it cannot continue to grow proportionally to the city’s population or affluence. Reduction of the resource footprint also means reduction of the plume of pollution and waste emanating from the city, both in dimensions and intensity. Since the city is an accumulator of substances, recycling and “mining” those very substances become an important source of materials for the city of the future and a way to reduce its resource footprint (Graedel, 1999). The city ecological relies for its survival as much as possible on natural means, both biological and energetic (Lewis, 1998). For instance, it uses wetlands to reduce wastewater treatment and conservative energy sources, such as wind and solar radiation, to mitigate energy demands. (Today’s conservative energy sources are insufficient to satisfy the needs of a city, and their exaggerated development can create in turn ecological stresses, as has occurred with the construction of extensive batteries of large windmills.)

Education Essential
A city intelligent is one that has the ability to adapt to change. Sensors, geographic information systems, telecommunications, the ability to simulate and to rapidly assess trends, and a nimble management structure are all new capabilities that enhance a city’s ability to adapt. A city intelligent must also be efficient in its use of resources, including human ones. It must have, for example, advanced traffic control systems and flexible scheduling of city activities to reduce congestion. Education is essential to the city intelligent and efficient, not only traditional education, but also an education for living appropriately in the city-learning how to behave in crowded situations and in traffic, how to reduce pollution through changing one’s behavior, and how to participate effectively in community decisions and understand the underlying issues.

A manageable city is one that finds an appropriate balance between what is local and what is centralized. It is a city that, no matter how large its population, relies on community participation as an indispensable component of making decisions, taking full advantage of information and telecommunications technologies. The city manageable endeavors to control its technologies and encourages the creation of technologies that better respond to its needs, rather than being powerless when confronted by new technologies. A good example is the automobile, which today has too large a footprint, demands that a large portion of the city be devoted to parking, and, universally, creates congestion. The city manageable stimulates new technologies to address the automobile’s size and parkability, not to mention its other environmental impacts.

Regardless of how it may be physically configured, the manageable city of the future must be governed by the clear recognition that it is an organic phenomenon that defies rigid planning but can be guided in desirable directions through a variety of possible organizational concepts. One concept that transcends any rigid geometric arrangement and can guide the organization of services, transportation, utilities, and other parts of the urban environment is to see the city as a complex “system of systems” (Gallopin et al., 2001) and to clearly identify the relationship among individual neighborhoods, larger neighborhood clusters, and the city as a whole.

Neighborhood As Organizing Unit
Viewing the neighborhood as an organizing unit of the city is not a new idea, but it is one that continues to make considerable sense for the city of the future. Walkable neighborhoods, for instance, help reduce congestion by facilitating the creation of a hierarchy of transportation hubs connecting the city’s components. In the developing world, where many cities are expected to double in population in the next 15 to 20 years, it should be easier in principle to devise entirely new organizations and systems than it is in the mature cities of the developed world. However, because of lack of resources and, at times, will, the reverse is often true.

Other important challenges for the manageable city are the role of self-help and sweat equity in housing the poorer segment of the population, the development of financial instruments such as public-private partnerships to encourage entrepreneurship and economic development, and the pooling of resources and markets with other cities to produce needed innovations. The relation of city policies to national policies-including policies to encourage viable alternatives to concentrating growth in the larger cities-is an important challenge for the city manageable, whether the city exerts influence because it contains a large portion of a nation’s population, or tends to be neglected because it is small.

Part of the challenge of making the city manageable is dealing with unrealistic expectations of its population-poor and well-off alike-in an era of burgeoning technological possibilities. These expectations can affect the stability of the city and may have global impact. In this context, the city manageable must also address the problem, particularly acute in the developing world, of how to reach rapidly growing areas with essential services by devising good-enough solutions as opposed to costly traditional infrastructural systems developed in affluent cities. As expressed by a felicitous analogy: It remains to be demonstrated who is more skilled, the surgeon who operates in a good environment and with the necessary assistance, or he who operates under emergency conditions with rudimentary instruments and facilities, sometimes below what is indispensable. (Lotti, 1989)

Fundamentally, a city is a complex bio-socio-machine entity that I shall call, for short, biosoma (Bugliarello, 1998, 2000). It is an entity created by the interaction of a biological component, that is, its inhabitants and other forms of life such as vegetation or microorganisms; a social component, the ensemble of collective activities, ideas, and organizations of its inhabitants; and a machine component, the artifacts, tangible and intangible, that support the life of the city.
Each of the three components of the biosoma has distinctive influences on the function and design of the city. The biological component can self-replicate and also be recycled by nature (e.g., through microbiological processes), capabilities essential to the sustainability of the city. Humans, in addition, bring emotions
and feelings that play a crucial role in the city caring and emotionally satisfying. The machine component embodies reliability, precision, and power, but also inflexibility. The social component embodies characteristics that fall between those of the other two. Like the machine, it increases the reach of the individual and can have reliability, precision, and power (e.g., in social organizations such as bureaucracies), but it also harbors collective feelings and emotions that on occasion can erupt with unforeseeable consequences.

Balance among the three biosomic components is important to maintaining the city’s positive characteristics while reducing its dysfunctionalities. For example, there ought to be balance between bioremediation and traditional methods of water and wastewater treatment or between tasks performed by humans and those performed by machines (e.g., a policeman directing traffic versus the use of traffic control devices). Balance considerations have far-reaching implications in making the city caring or manageable. Thus, a totally automated city, technically possible, becomes also an inhuman city. Similarly, within the biological component, the balance between humans and other species determines the extent to which the city favors biological diversity-the plants and animals that enrich the life and the environment of humans.

Trade-Offs Central to Biosoma Paradigm
Within the biosoma paradigm, trade-offs among information, materials, and energy are central to the concept of “intelligent” infrastructure, such as the intelligent highway that can accommodate more traffic without requiring the construction of new roadway. Trade-offs between materials and energy range from the simple but ecologically significant one of using insulation instead of active heating and cooling, to that embodied in the utopian concept of a domed city, unworkable for a variety of reasons but the epitome of the desire to use material structures to control climate and therefore the energy expenditures of the city. The trade-off between biological and machine energy affects the extent to which walking or bicycling can replace motorized means of transportation, an important consideration in the design of cities as clusters of neighborhoods. The biosomic city shaped by these balances and trade-offs is continually evolving. As each component of the biosoma changes so, too, does the balance among them.

The emerging knowledge city and eco-industrial city are embryonic manifestations of the biosomic city of the future. In the knowledge city (Figure 2), the emphasis in each of the three biosoma components is on knowledge and information: in the biological component, on learning and biotechnology; in the social component, on education and e-business; and in the machine component, on computers, telecommunications, and nanotechnology.

One instrument of the knowledge city, congruent with the concept of neighborhoods and clusters, is the knowledge park. It coalesces socioeconomic activities around institutions that generate knowledge (e.g., universities or research centers), transmit knowledge (e.g., schools), and use knowledge (e.g., business or industry and government). These institutions are increasingly crucial to the socioeconomic development of a knowledge society and attract to them other elements of the city’s organization and infrastructure.

The knowledge park provides a new organizing principle for the knowledge city. Such parks can transform the urban environment and provide an enormous economic boost, as was the case with Metrotech, catalyzed in Brooklyn, New York, by Polytechnic University. Metrotech has attracted some 20,000 jobs around the university, mostly in information technology and telecommunications, and has revived a significant part of downtown Brooklyn (Bugliarello, 1996). An increasing dimension of the evolving knowledge city is also virtuality-the ability to conduct at a distance business transactions and other social interactions.

In the eco-industrial city, the waste of one industry becomes the input to another. In addition, the biological and machine components are integrated and support each other, as in the case of bioremediation of polluted areas. A pioneering example of this integration is the Danish city of Kalundborg (Graedel, 1999). Whatever shape the city of the future might assume, the challenge to its planners, its managers, and its citizens is to determine consciously what the desirable bio-social-machine balance should be.

Creating the City of the Future
Creating the city of the future presents major and unprecedented engineering challenges. One is how to maintain internal conditions within acceptable limits as the city is exposed to changes in temperature, winds, floods, and earthquakes, as well as to anthropogenic disasters such as war and terrorism. The challenge is to reduce the influence of these parameters on the city through appropriate design and operational decisions. For instance, although a city totally covered by a dome is unrealistic, it is not unrealistic to engineer the city skyline-the location and configuration of structures-to affect temperature and wind patterns. A second challenge is to minimize the influence of the city-its wastes and noxious emissions-on its surroundings, such as watersheds. A third challenge is to develop technology for addressing problems at the microscale of the neighborhood or the individual home, such as in-house energy transformers, waste disposal and recycling systems, and the virtual office. Where appropriate, such technology would provide alternatives to the macroscale of trunk utilities and other central services.

To transform today’s cities into tomorrow’s less dysfunctional ones, resources are necessary, but the will to transform will be even more important and generally more difficult to mobilize. The fundamental instrument for generating that will is education. Citizens need to learn what they could reasonably expect the city to be and what it takes to make their expectations reality. They need to recognize the importance of participating in decision-making and of having the discipline to make sacrifices in the short term for the sake of a greater good in the long term. Similarly, the city must be willing, when necessary, to accept some temporary economic losses in order to secure a more sustainable future.

Current trends strongly suggest that the cities of the future will be home to an increasing share of world population. We do not know, however, at what point in time saturation will be reached or whether urban population might eventually decline. Neither do we know whether the city of the future will be more dense and compact or more spread out (Figure 3). Regardless of these uncertainties, however, we already possess much of the knowledge and technology to make the city of the future a more effective, less dysfunctional instrument of human advancement. We can expect new technologies to strengthen this capability (Ausubel and Herman, 1988). But they must be developed and applied in the context of a vision of the city of the future that is caring and emotionally satisfying, ecological, intelligent, and manageable. Given the rapid pace of urbanization and the exacerbated dysfunctionality of many of today’s cities, we cannot tarry.


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About the Author:George Bugliarello is chancellor of Polytechnic University in Brooklyn, N.Y. This article is based on remarks he made on 24 October 2000 during the NAE Annual Meeting Technical Session.