ADB plays a pivotal role in improving the quality of life in cities throughout Asia and Pacific Asia’s cities are core contributors to national development. Rapid urban growth will mean that by 2020, half of Asia’s expected 4 billion people will be city dwellers. Unfortunately, they face a host of challenges. Populations are increasing, especially in slums. Environmental and health problems are growing, and over-consumption of nonrenewable resources is creating environmental nightmares.