Beyond trees

Abstract

More than half of the world's population lives in urban areas. By 2050, that number is expected to increase to at least 70 percent—and the densest of these areas will be concentrated in Asia and Africa. Cities around the world are feeling the strain of increasing population density. Unplanned urban growth has placed heavy pressures on resources and infrastructure. This intensification has led to land use and tenure issues, rising poverty and unemployment, an increasing gap in wealth distribution, and further marginalization of disinvested populations. Approximately 1 billion urban (and peri-urban) dwellers live in informal settlements or slums (Ooi and Phua 2007) with no access to basic services, green spaces, food security, and safety. In addition, many of these communities have become more vulnerable to destructive natural and climate-related disasters, diseases, and other ecological and social stresses.