Cities at the forefront – Population Growth and Urbanization

Cities at the forefront – Population Growth and Urbanization – Abstract

Don Hinrichsen

Cities in the developing world are at the forefront of the global struggle to achieve better living standards. How urban residents and their governments meet the challenges of rapid population growth and development will largely determine the kind of world that lies ahead.

Marina Lupina and her two children live in one of Manila’s largest slum areas, in a shack built from discarded waste next to a refuse-clogged canal. They have no running water, no electricity, and little furniture–a bed where all three sleep, a table, and three chairs. Her husband disappeared after the second child was born. By selling recycled cloth, Marina earns just enough to buy rice, fish, and clothing. Like millions of others in the big cities of developing countries, she has come for a better life. Despite her poverty, she believes that she and her children have more opportunity in the city than if they had remained in the countryside.

Within five years half the world’s population will live in cities. By 2030 the urban population will reach 4.9 billion–60% of the world’s population (28) (see Figure, p. 2). Nearly all population growth will be in the cities of developing countries, whose population will double to nearly 4 billion by 2030–about the size of the developing world’s total population in 1990.


“The explosive growth of cities in developing countries will test the capacity of governments to stimulate the investment required to generate jobs and to provide the services, infrastructure, and social supports necessary to sustain livable and stable environments,” warns an assessment of expert opinion prepared by the US National Intelligence Council in 2000 (16). Developing countries also will face intensified environmental problems due to urbanization.

How can living conditions improve for the millions of people densely packed into cities without destroying the natural resource base on which improved living standards depend? Meeting the challenges posed by rapid urbanization could be as important for the future as addressing rapid population growth itself has been over the last 50 years.

Developing World Becoming Urban

The developing world has been predominantly rural but is quickly becoming urban. In 1950 only 18% of people in developing countries lived in cities. In 2000 the proportion was 40%, and by 2030 the developing world will be 56% urban (2, 28). While the developed world is more urban, estimated at 76% urban in 2000, developing countries have much faster urban population growth–an average annual growth rate of 2.3%, which far exceeds the developed world’s urban growth rate of 0.4% (28).

Rapid urban growth in developing countries reflects substantial migration to cities from rural areas and also natural population increase (the net effect of births minus deaths) among city residents. On average, of these two sources of urban population growth, natural increase plays the greater role. Among developing countries, excluding China, for example, an estimated 60% of urban growth between 1960 and 1990 was from natural increase and 40% from in-migration from rural areas and the expansion of urban boundaries (2).

Some cities, however, are growing two or three times faster than the country’s overall population, reflecting massive migration to cities (7, 10). For example, Dhaka grew in population by an average of nearly 7% per year from 1975 to 2000 compared with an annual average of 2.1% for Bangladesh as a whole. In the same period, the population of Lagos grew at an average of 5.6% per year compared with 3% for Nigeria as a whole (28, 31).

Megacities. More and more people of the developing world live in “megacities,” or cities of at least 10 million people. In 1975 only five cities worldwide had 10 million or more inhabitants, of which three were in developing countries. The number will increase to 23 by 2015, all but 4 of them in developing countries. By then, Bombay, Dhaka, Lagos, and Sao Paulo each will have over 20 million residents (see Table, p. 3) (28). Also, by 2015 an estimated 564 cities around the world will contain 1 million or more residents. Of these, 425 will be in developing countries (2).

The Urban Dilemma

The rapid growth of cities in developing countries presents a dilemma. Cities historically have been centers of industry and commerce and magnets for millions of people. Today, however, the sheer size of cities and the rapid, continuing influx of urban migrants cast doubt on their ability to continue providing improved standards of living.

While there is no evidence that a threshold population size exists beyond which “cities generate more negative than positive effects for their countries” (2), in many cities the rapid pace of population growth and enormous size of the population have overwhelmed the capacity of municipal authorities to respond. Over 600 million people in the cities of developing countries cannot meet their basic needs for shelter, water, food, health, and education (6). Recent migrants to cities are particularly vulnerable, often clustered in slums with little access to jobs or services (9).

In 1987 the World Commission on Environment and Development stated that, “in the space of one decade, the developing world will have to increase by 65% its capacity to produce and manage its urban infrastructure, services, and shelter–merely to maintain present conditions” (29, 35). That challenge has not been met. The infrastructure in most cities of developing countries has not been able to keep up with rapid population growth and the unplanned expansion of industries (23).

Still, people keep moving to cities. For all their problems, big cities in developing countries continue to be centers of economic activity, offering more potential than most rural areas can offer (8). Cities will continue growing as millions of people leave behind deteriorating rural economies, flee wars and civil strife, or relocate as population pressures overwhelm agricultural land and rural environments (2, 15, 17). If cities are not able to cope with the influx, however, poverty and hopelessness could become widespread, leading to rising discontent and civil unrest (2, 12).

Health and Pollution

Around the world, atmospheric pollution afflicts more than 1.1 billion people, mostly in cities (21). Another 2.5 billion are at risk from high levels of indoor air pollution (22). Indoor and outdoor air pollution together kill nearly 3 million people every year–about 6% of all deaths annually–and 90% occur in developing countries (18, 26, 36). As cities expand, urban air pollution worsens. In most big cities vehicle exhaust levels already are so severe that pollution-related ailments cost huge amounts for medical care and in worker absenteeism (14, 29).

Both water scarcity and water pollution are serious urban problems. Dirty water is by far the largest environmental killer around the world, claiming some 5 to 12 million lives a year, depending on the definition of water-related disease (4). According to the World Health Organization (WHO), the majority of urban populations in developing countries do not have access to proper sanitation facilities–a flush toilet, sanitary latrine, or a pit that can be covered over–and about half lack a regular supply of potable water (36).

Environmental Impact of Cities

Cities have a huge impact on the natural environment. As cities grow ever larger, they consume more and more natural resources to meet the rising demand for food, water, energy, and goods and services, both from people and industry (13, 30). Cities generate close to 80% of all carbon dioxide emissions and account for three-quarters of industrial wood use. Some 60% of all freshwater withdrawn for human use ends up in urban areas–either directly for use in factories and for drinking and sanitation, or indirectly through the consumption of irrigated crops (18).

The economic and environmental reach of the city goes far beyond the city limits. Modern high-density settlements now appropriate the ecological output and life-support functions of distant regions through trade and commerce, the generation and disposal of wastes, and the alteration of nature’s cycles. As cities continue to attract more people and produce and consume more, they become “black holes” that soak up the ecological output of entire regions (20).

What Can Be Done?

Alarmed by massive population growth, worsening living conditions, and environmental degradation, some experts worry that cities in developing countries have become unmanageable. Others are more optimistic, observing that with good management cities can grow even larger without making residents worse off and without ruining the surrounding environment (2, 3).

While many city governments face unprecedented challenges, a number of steps can make cities more livable and protect the environment. These include better urban planning, more public transportation, better sanitation and rational water use policies, energy conservation, urban farming, and waste recycling. In addition, slower population growth would ease pressures on cities and buy time to find solutions.

Better planning and public transportation. In many cities better planning, coupled to effective zoning, could improve the quality of life for urban residents and protect the environment. For example, zoning could locate polluting industries away from residential areas. Green belts around highways and industrial centers could cut down on congestion and pollution. Effective city planning requires strong local government supported by active citizen groups working for improvements in the quality of life (37).

One of the best investments cities can make–both environmental and economic–is in efficient mass transportation systems. A good mass transportation system can create jobs by providing an affordable way for residents to reach places of employment. It also can greatly reduce pollution by reducing the demand for private vehicles. WHO estimates that about 700,000 deaths annually could be prevented in urban areas of developing countries if the three major pollutants–carbon monoxide, suspended particulate matter, and lead–were brought down to safe levels defined by WHO (5, 36).

Providing water, improving health. Many cities in developing countries are growing so fast that they cannot manage the water supply. In developing countries as much as 70% of the water pumped into cities is lost before it can reach consumers, leaking out of faulty water mains, pipes, and faucets (33).

Cities can gain a great deal from adopting water conservation measures. A key to urban water conservation is pricing water to reflect its value as a scarce resource. Pricing water minimally or not at all encourages waste. Charging higher prices would not necessarily deny water to low-income areas, however. In Tegucigalpa, Honduras, for example, six neighborhoods together approached the city water authority with a request to provide piped water. Consumers themselves paid for the water connections. Nevertheless, the price that households paid for water dropped because residents no longer had to buy expensive water from street vendors, and the quality of their water improved (19).

Conserving energy. Developing-country governments have far to go in encouraging more efficient energy use. Energy prices often drop dramatically for consumers when utilities invest in energy efficiency. More efficient energy use also is a good investment for utilities because it helps avoid the need to build costly power plants, and it reduces the amount of pollutants pumped into the atmosphere.

The “energy crisis” of the early 1970s caused a surge of energy efficiency measures in Europe and the US. By 1985 the use of more efficient household appliances, along with more stringent efficiency standards required in buildings, brought dramatic energy savings to US consumers and helped make it possible for US utilities to avoid building 350 megawatts worth of power plants. These innovations helped spawn a US$3 billion-per-year energy conservation industry, funded by the utilities, whose average payback time on investment in energy conservation was only about one year (11, 34).

Urban farming and recycling. Urban farming helps feed city residents. It also helps protect the environment by reducing the need to bring in food. The UN Development Program has estimated that about 800 million urban and peri-urban farmers produce over 15% of the world’s food (27). If city governments adopted explicit policies and incentives to encourage urban agriculture, the number of urban farmers would likely increase substantially.

Until the mid-1990s, when massive population growth and rising demand overwhelmed local food supplies, urban farmers in China’s 18 largest cities were able to produce over 90% of locally consumed vegetables and half of all the meat and poultry. Hong Kong still produces two-thirds of the poultry, half the vegetables, and 40% of the fish it consumes. Singapore produces all of its meat and fish and one-quarter of its vegetables (18, 27).

Recycling–converting mountains of urban waste into new resources–also makes sense both economically and environmentally. Economically, for every 1 million tons of solid waste, about 1,600 recycling jobs could be created in developed and developing countries alike, according to industry surveys (38). Recycling, of course, benefits the environment by saving natural resources and reducing the amount of trash in landfills or dumped into rivers, lakes, and oceans.

Population and Family Planning: Toward Sustainable Cities

Worries about a global “population bomb” may have lessened as fertility rates have fallen in most developing countries. Nevertheless, the world’s population continues to grow by nearly 77 million people each year–almost all in developing countries. Urban areas are gaining about 60 million people per year (24, 28). While fertility has fallen to replacement level in 61 countries–13 of them in the developing world–about 1.8 billion people live in 43 countries where fertility averages between three and five children per woman. In 48 other countries with a combined population of about 760 million, the average woman has more than five children (24).

Since the 1960s family planning programs have played a key role–perhaps the key role–in slowing population growth in developing countries (32). Between 20% and 50% of the fertility decline in developing countries has come as a direct result of family planning programs (1).

Today, for the urban areas of developing countries, meeting the family planning needs of city residents is a promising strategy not only to improve health but also to slow population growth (2). In particular, programs can do more to reach the urban poor, including recent migrants, who live in areas that often have not been served well (9). By enabling people to have the number of children they want, family planning programs can help make cities more livable today while, by slowing population growth, they help safeguard natural resources needed for the future.


Cities with 10 Million or More Inhabitants,

1975, 2000, and 2015 (Population in Millions)

City–1975 Population

Tokyo 19.8

New York 15.9

Shanghai 11.4

Mexico City 11.2

Sao Paulo 10.0

City–2000 Population

Tokyo 26.4

Mexico City 18.1

Bombay 18.1

Sao Paulo 17.8

Shanghai 17.0

New York 16.6

Lagos 13.4

Los Angeles 13.1

Calcutta 12.9

Buenos Aires 12.6

Dhaka 12.3

Karachi 11.8

Delhi 11.7

Jakarta 11.0

Osaka 11.0

Metro Manila 10.9

Beijing 10.8

Rio de Janeiro 10.6

Cairo 10.6

City–2015 Population

Tokyo 26.4

Bombay 26.1

Lagos 23.2

Dhaka 21.1

Sao Paulo 20.4

Karachi 19.2

Mexico City 19.2

Shanghai 19.1

New York 17.4

Jakarta 17.3

Calcutta 17.3

Delhi 16.8

Metro Manila 14.8

Los Angeles 14.1

Buenos Aires 14.1

Cairo 13.8

Istanbul 12.5

Beijing 12.3

Rio de Janeiro 11.9

Osaka 11.0

Tianjin 10.7

Hyderabad 10.5

Bangkok 10.1


UN Population Division,

March 2000 (28)

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This issue of Population Reports was prepared by Don Hinrichsen, Richard Blackburn, and Bryant Robey. Stephen M. Goldstein, Managing Editor. Linda D. Sadler, Designer. Production by John Fiege.

Phyllis Tilson Piotrow, Ph.D., Director, Center for Communication Programs and Principal Investigator, Population Information Program. Ward Rinehart, Project Director.

The Johns Hopkins Center for Communication Programs, including the Population Information Program and Population Communication Services, provides leadership, technical assistance, and support for family planning and related health communication to health professionals, their clients, and the public.

Published with support from the United States Agency for International Development (USAID), Global, G/PHN/POP/CMT, HRN-A-00-97-0009-00. The opinions expressed herein are those of the authors and do not necessarily reflect the views of the US Agency for International Development or the Johns Hopkins University.

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