Global Environment Outlook 3 (GEO 3)

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STATE OF THE ENVIRONMENT AND POLICY RETROSPECTIVE: 1972–2002

UNEP, Hartmut Schwarzbach, Philippines, Still Pictures

Urban areas

Global overview Nearly half of the world’s population (47 per cent) lives in urban areas, a figure which is expected to grow by 2 per cent per year during 2000–15 (United Nations Population Division 2001a). The accumulation of people, their consumption patterns, travel behaviour and their urban economic activities have a large impact on the environment in terms of resource consumption and waste discharges. However, cities also offer opportunities to manage a growing population in a sustainable way. Urbanization Increasing levels of urbanization are caused by natural growth of the urban population and migration of the rural population towards cities. Over the past half- century, a great rural-to-urban population shift has occurred and the process of urbanization (the concentration of people and activities into areas classified as urban) is set to continue well into the 21st century. Driving forces include the opportunities and services offered in urban areas — especially jobs and education — while in some parts of the world,

notably Africa, conflict, land degradation and exhaustion of natural resources are also important (UNEP 2000). Cities play a major role not only as providers of employment, shelter and services but also as centres of culture, learning and technological development, portals to the rest of the world, industrial centres for the processing of agricultural produce and manufacturing, and places to generate income. There is a strong positive link between national levels of human development and urbanization levels (UNCHS 2001b). However, the implications of rapid urban growth include increasing unemployment, environmental degradation, lack of urban services, overburdening of existing infrastructure and lack of access to land, finance and adequate shelter (UNCHS 2001b). Managing the urban environment sustainably will therefore become one of the major challenges for the future. Levels of urbanization are closely correlated with national income — the more developed countries are already mostly urbanized — and in almost every country, urban areas account for a disproportionate share of the gross national product (GNP). Bangkok,