By 2050, about 70 per cent of the world’s population is projected to live in urban areas. Rapid urban growth is mainly occurring in countries least able to cope with the demand for decent jobs, adequate housing and urban basic services. Close to one billion people, or 33 per cent of the urban population in developing countries, live in slums, in inequitable and often life-threatening conditions. If left unaddressed, these trends may become sources of social and political instability.
Sixty per cent of the built environment required to accommodate the earth’s urban population by 2050 remains to be built. For most, higher fuel prices, climate change and limits to fresh water will present a major challenge to urban growth. At the same time, these challenges constitute an opportunity to demonstrate that growth can occur at lower rates of environmental degradation. This is the essence of sustainable urban development. The innovations required to deliver it will almost certainly arise from the concentration of institutions, people and infrastructure that cities naturally provide.
When sensitively planned and appropriately supported by sustainable infrastructure, compact cities constitute the world’s most efficient settlement pattern. Densification reduces spatial footprint and makes shared infrastructure viable. These in turn reduce emissions and resource use. Compact cities also allow new technologies to be tested and implemented more competitively. Over the long term, cities can strengthen resilience by reducing dependence on carbon intensive growth, stimulating efficiency in resource use, and expanding skills for work in a green economy.