MORE PEOPLE will live in cities by the year 2025 than occupied the whole planet ten years ago. A new report, World Resources 1996–97, from the World Resources Institute, the United Nations Environment Program, the United Nations Development Program, and the World Bank finds that urbanization is reshaping the physical and social environment as it fuels economic growth and spurs environmental degradation.
Urban environmental conditions are important to the health and quality of life of a city’s inhabitants and can impose significant costs on economic and social development. The impact of urban areas on the surrounding environment is an issue of growing concern. More than half of humankind will live in urban areas by the end of the century, and 60 percent by 2020 (Chart 1). In most nations, cities generate a majority of the economic activity, ultimately consume most of the natural resources, and produce most of the pollution and waste. Thus, urban environmental issues, although often overlooked, are important both locally and on national and global scales. Neglect of these issues could compromise larger economic, social, and environmental goals in both developed and developing countries.
The developed world is already largely urbanized. In the developing world, the rapid urbanization now under way will increasingly concentrate both population and economic growth in cities—as much as 90 percent of future population growth and a major share of future economic growth—intensifying the problems of the urban environment. In recent decades, urban areas in developed countries have made major progress in cleaning up local environmental problems, but they remain significant contributors to regional and global environmental burdens. In developing countries, urban areas often have huge populations living in poverty. Their problems are similar to those of the rural poor—lack of access to clean water, sanitation, and adequate housing—compounded by overcrowding and exposure to industrial wastes and urban air pollution.
Burgeoning cities are expanding into fragile ecosystems. Cities sometimes deplete nearby areas of water and firewood, rendering them less capable of supporting rural populations and thus adding to the pressures for urban migration (Chart 2). Air pollution already exceeds health standards in many megacities in developing countries. Sewage and industrial effluents are released into waterways with minimal or no treatment, threatening human health and aquatic life. Thus, in the absence of policy reform, stronger institutions, and enlightened political leadership, economic and population growth in developing countries in the near term may lead to a deterioration of the urban environment, both physical and social.
Three issues emerge as particularly critical: water supply, sanitation, and water resource management; solid waste management; and air pollution. In each area, there are compelling economic, social, and environmental rationales for change. Successful efforts, however, are likely to require significant changes in urban practices and strategies.
Chart 1Urban population growth Chart 2Population subject to water scarcity
Source: World Resources Institute.
Beyond the immediate priorities for improving the urban environment lies the need to strengthen local governments, to implement new approaches to alleviating poverty and supporting communities, and to develop more environmentally friendly cities. Virtually all of the policies needed to improve the urban environment require more effective urban governance. That will require not only strengthened governments but also the involvement of many other actors in the urban environment—including the poor and the private sector. Community-based approaches are essential if urban services are to reach those who need them and if there is to be broad-based support for needed changes in strategies and practices. The sheer size of urban populations and economies means that cities must lead the way toward more environmentally sustainable practices for the world as a whole.
This article is drawn from World Resources 1996-97, a joint publication of the World Resources Institute, the United Nations Environment Program, the United Nations Development Program, and the World Bank, Oxford University Press, Oxford, 1996.