The world is in the midst of a massive urban transition unlike that of any other time in history. Within the next decade, more than half of the world’s population, an estimated 3.3 billion, will be living in urban areas – a change with vast implications both for human well-being and for the environment. As recently as 1975, just over one third of the world’s people lived in urban areas. By 2025, the proportion will have risen to almost two thirds.
The most rapid change is occurring in the developing world, where urban populations are growing at 3.5 percent per year, as opposed to less than 1 percent in the more developed regions. Cities are also reaching unprecedented sizes – Tokyo, 27 million; Sao Paulo, Brazil, 16.4 million; Bombay, India, 15 million – placing enormous strains on the institutional and natural resources that support them.
Historically, cities have been driving forces in economic and social development. As centers of industry and commerce, cities have long been centers of wealth and political power. They also account for a disproportionate share of national income. The World Bank estimates that in the developing world, as much as 80 percent of future economic growth will occur in towns and cities. Nor are the benefits of urbanization solely economic. Urbanization is associated with higher incomes, improved health, higher literacy, and improved quality of life. Other benefits of urban life are less tangible but no less real: access to information, diversity, creativity, and innovation.
Yet along with the benefits of urbanization come environmental and social ills, some of staggering proportions. These include a diversity of problems, from lack of access to clean drinking water, to urban air pollution, to greenhouse gas emissions. Although urban environmental problems defy easy categorization, they can be grouped into two broad classes: those associated with poverty and those associated with economic growth or affluence. The two often coexist within the same city.
Some of the worst problems, in terms of human suffering, occur in the poorest cities of the developing world. Especially where population growth is rapid, local governments are unable to provide for even the most basic needs of their citizens. Throughout the developing world, the urban poor live in life-threatening conditions. At least 220 million urban dwellers lack access to clean drinking water; more than 420 million do not have access to the simplest latrines. Between one and two thirds of the solid waste generated is not collected. It piles up on streets and in drains, contributing to flooding and the spread of disease. The problems of urban poverty exact an enormous toll in largely preventable deaths and diseases.
Environmental problems are also severe in those developing world cities experiencing rapid economic growth. Economic growth brings needed revenues to cities, but, if proper safeguards are not in place, it all too often occurs at the expense of environmental quality. More than 1.1 billion people live in urban areas where air pollution levels exceed healthful levels. In cities across the world, domestic and industrial effluents are released to waterways with minimal or no treatment, threatening both human health and aquatic life. These cities still harbor huge populations of the urban poor who are shut off from the benefits of economic growth. Many live in vast squatter settlements, where they are exposed both to the hazards resulting from economic growth, such as industrial emissions, and to the hazards that accompany poverty.
In the wealthiest cities of the developed world, environmental problems are related not so much to rapid growth as to profligate resource consumption. An urban dweller in New York consumes approximately three times more water and generates eight times more garbage than does a resident of Bombay. The massive energy demand of wealthy cities contributes a major share of greenhouse gas emissions.
This special section of World Resources 1996-97 examines the range of environmental problems and the forces contributing to them in cities of both the developed and the developing world. It then explores the nature of the environmental challenge facing the world’s cities. The most immediate and pressing challenge is to improve environmental conditions for the urban poor in the developing world. Given the constraints of rapid population growth and limited financial resources, different strategies will be needed from those previously used in cities in developed regions; these approaches will involve not only technological advances but also efforts to address urban poverty.
A second, and related, challenge is for cities to reconcile the often-competing demands of economic growth and environmental protection. For cities in developed countries, that means reducing their excessive consumption of natural resources and its toll on the global commons. Such strategies are equally important for cities in the developing countries, if they are to avoid the problems of affluence so prominent in the developed world.
Though sobering, these challenges are not insurmountable. Because of their concentrated form and efficiencies of scale, cities offer major opportunities to reduce energy demand and minimize pressures on surrounding lands and natural resources. If cities can harness the energy and creativity of their citizens and build on the inherent advantages that urbanization provides, they can, in fact, be part of the solution to the global problems of poverty and environmental degradation.
References and notes
1. United Nations (U. N.) Population Division, World Urbanization Prospects: The 1994 Revision (U. N., New York, 1995), p. 87.
2. Ibid., pp. 86-87, 102-103.
3. Op. cit. 1, p. 27.
4. Op. cit. 1, pp. 132, 135.
5. Carl Bartone et al., “Toward Environmental Strategies for Cities: Policy Considerations for Urban Environmental Management in Developing Countries,” Urban Management Programme Policy Paper No. 18 (The World Bank, Washington, D. C., 1994), pp. 9-10.
6. G. Watters, Health and Environment, World Health Organization, Geneva, 1995 (personal communication).
7. Jorge E. Hardoy, Diana Mitlin, and David Satterthwaite, Environmental Problems in Third World Cities (Earthscan, London, 1992), p. 58.
8. Dietrich Schwela, “Public Health Implications of Urban Air Pollution in Developing Countries,” paper presented at the Tenth World Clean Air Congress, Erjos, Finland, May 28-June 2, 1995 (World Health Organization, Geneva, 1995).
9. World Resources Institute, The 1994 Information Please Environmental Almanac (Houghton Mifflin Company, Boston, 1994), pp. 205, 209.
10. National Institute of Urban Affairs (NIUA), Urban Environmental Maps: Delhi, Bombay, Vadodara, Ahmedabad (NIUA, New Delhi, India, 1994), pp. 2. 21-2. 22.