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Author: George Bugliarello
The large urban agglomerates we call megacities are increasingly a developing world phenomenon that will affect the future prosperity and stability of the entire world.
The concentration of the world’s population in urban areas is growing at an enormously rapid rate, and within that phenomenon, projections call for even more rapid growth of megacities, currently defined by the United Nations (UN) as cities of over 10 million people.1 From 1975 to 2015, the number of megacities will have grown from five -- three of them in the developing world -- to 26 -- all but four in the developing world (UN, 1998).
The definition of what is a megacity is clearly arbitrary, as the population concentration that differentiates megacities from other urban areas changes with time and context. In the ancient world, Rome, with its over 1 million inhabitants, was a megacity, and today, London or Chicago could be considered megacities, even if they fall below the 10 million UN threshold.
Although there are numerous examples in the developed world, megacities are primarily a phenomenon of the developing world. If one considers population projections for the 11 largest urban agglomerates in 2015 (Figure 1), in 15 years most of the largest cities of the world will be in the developing world, a significant change from the largest city populations in 1980 and 1994. Although Tokyo will remain the largest city in the world, New York, at second place in 1980 and 1994, is projected to be at the bottom of the list by 2015, while Mumbai will have climbed from sixth to second place, and Jakarta from last to fifth place. Both Tokyo and New York are experiencing relatively modest population increases, and a number of other large cities in the developed world are experiencing population declines. In contrast, the populations of developing world megacities are typically growing from one to five percent per year, although these rates are expected to abate somewhat in the next 15 years (UN, 1998). However, if all the megacities of the world -- developed and developing alike -- have one factor in common, it is the great diversity in many of their salient indices, from cost of living to mobility, that often reflects differing approaches to public policies (Parker, 1995).
Despite the fact that megacities are increasingly a phenomenon of the developing world, there are three major reasons why the developed world needs to pay attention to them. First, what happens in the megacities of the developing world affects the rest of the world. The combination of high population density, poverty, and limited resources makes the developing world megacity an environment which favors the incubation of disease, from cholera to tuberculosis to sexually transmitted infections, that in an age of rapid communication can almost instantaneously be propagated to the rest of the world. Vulnerability to terrorism, natural hazards, ecological disasters, war conditions, and food scarcity are also exacerbated in the megacities of the developing world. As recent episodes have shown, attacks against embassies, businesses, and travelers directly affect the developed world, particularly the United States.
Megacities, both in the developed and the developing world, are places where social unrest often originates, as demonstrated currently in Jakarta, and historically in Paris and St. Petersburg, the megacities of their time that sparked the French and Russian Revolutions. Such unrest affects the rest of the world, as do other phenomena of megacities, including the rate at which their residents emigrate to other areas, and the competitive challenge presented by their cheap labor forces. Last but not least, the ecological impacts of sprawling megacities extend to other regions of the world, as seen with the air pollution generated by millions of households burning soft coal, or with the disposal of waste, a universal problem epitomized by the odyssey of New York City’s waste-laden barges.
The second major reason to pay attention to megacities is that they are key instruments of social and economic development. In a world concerned with the growth of the global population, megacities are strong indicators of both present and future conditions: they have become instruments for dramatic birthrate reductions in comparison to other regions of the countries in which they are situated; they are instruments to promote human genome diversity because they attract diverse populations; they are the site of cultural and educational institutions that promote social development; they often set the tone for a nation’s social values; and they are powerful instruments of economic concentration (for example, today Karachi generates 20 percent of Pakistan’s gross domestic product and provides 50 percent of government revenues).
A third reason to pay attention to megacities is that they offer new market opportunities to both the developing and developed world alike, as discussed further below.
To understand the role of the megacities in our world today, we need to understand their dynamics. A megacity is a complex organism and its development is largely a spontaneous process. It is not an entity that can be totally designed, as has been learned from a number of planning failures, exemplified by Brasilia, or, in New York and several other U.S. cities, by the so-called projects for low-income tenants. However, if it cannot be totally designed, the megacity can be guided in its evolution through realistic planning.
The first question, in terms of dynamics, is: Why do megacities attract? Why do such large populations flow to them and want to live in them? In the developing world, megacities attract those who are seeking a better life -- a higher standard of living, better jobs, fewer hardships, and better education.
The second question is: Why, if they have such force of attraction, do megacities have what appears to be a formidable set of increasingly intractable problems? The problems of megacities include: