Cities in Asia have grown faster than any other urban areas in the world. Yet, urban planning has often been an afterthought. By 2015, there will be 12 Asian megacities, and by 2022 in the region there will be more people living in cities than in the countryside.

Urbanization comes with costs. Noise and congestion are among the most apparent features of cities. City living entails higher costs for housing, raising children, and health care. In addition, income inequality and crime rates tend to be higher in urban areas.

Asia has already been facing enormous environmental challenges. Three of the top five carbon dioxide (CO2) emitting economies and 11 of the 20 most polluted cities in the world are in Asia. In many Asian nations, losses from traffic-related congestion amount to 5% of gross domestic product (GDP). The situation is particularly worrisome in poor cities that experience rapid growth, where pollution is becoming extremely serious, infrastructure supply lags behind demand, and basic public services such as water connections and solid waste disposal do not reach the majority. In addition, many residents live on marginal lands where they face risks from flooding, disease, and other shocks.

Urbanization increases vulnerability because life and asset losses are much larger in cities than in the countryside when a disaster strikes. In this context, the issue of climate change becomes particularly relevant to cities. Climate change is recognized to have caused extreme weather and rising sea levels. While there are many unknowns about the extent and timing of these impacts, the consensus is that the challenge is real and imminent, and that different cities will face urgent challenges.

Among the consequences of climate change are an increase in the intensity and frequency of floods and sea level rise. Poorer cities that are below sea level are the most susceptible. This is especially relevant for Asian nations such as Bangladesh and the Pacific Island countries, although data for the latter are often unavailable. Many Asian cities, and especially some megacities, have been built in the deltas of major rivers where ports could link the cities to the global economy. So it is not surprising that many Asian cities are flood prone. Some such cities may have extensive experience dealing with floods. For example, Dhaka has an elaborate set of mud banks for protection. But increased flooding induced by climate change may well push these cities' infrastructures beyond their current capacities, as occurred in Bangkok in late 2011. Developing further coastal engineering protection will place an increasing burden on the resources of such cities.

People in Vinh Yen in Viet Nam are not unique in their aspirations for a livable city. Throughout Asia, people are recognizing that cities serve a function beyond business and economic growth. They are places where people live, children go to school, and families spend time together. The quality of the air, water and land in these cities has a direct impact on millions of people.

How can Asian cities be transformed from sprawling, gridlocked and polluted commercial centers into healthy, livable areas that can be sustained for decades? The transformation of Asia’s cities requires a complete rethink of the way urban areas are developed and managed. The cleanliness of air, water and land need to be pushed to the forefront and ideas about public space need to include to all residents of a city – including families, children, the elderly and the poor.

The Asian Development Bank has developed an operational framework that helps cities in the region realize their aspirations to develop greener, more livable environments.

This includes thinking differently about the way cities are managed, including blending urban planning and environmental management.

To achieve their goals, people living in urban areas have developed Green City Action Plans and new, innovative partnerships.

To make cities more livable, the focus is on improving air, land and water through management of the environment, economic competitiveness and equity.

Good planning and engineering design are being balanced with the efficient use of natural resources.

In many cities across the region, people and governments are taking the initiative to make the difficult changes needed to improve the environment in which they live. They are making plans, taking actions and sharing ideas and information.