In 2005, green architect William McDonough and British engineering firm Arup separately announced plans to build ambitious eco-cities housing up to 500,000 inhabitants in mainland China. In recent months, Newsweek, Popular Science and other publications have looked at how these cities are actually shaping up -- and the reality on the ground so far is disappointing.

China recently broke ground on Dongtan, which it calls the world’s first eco-city. A ferry ride away from central Shanghai, Dongtan will ban all polluting cars, forcing people to get around using electric cars, bicycles, or just their legs. It will recycle as much as possible, including all its wastewater; grow food on its own environmentally sensitive farms; and create all its own energy in nonpolluting ways—wind, solar, and the burning of human and animal wastes. It will encourage, and in some cases require, the use of local labor and local, green building materials.

Most of these technologies are not new, and many are commonly used in Western Europe. What will make Dongtan unique are the integration of environmentally friendly practices and the strict exclusion of older, polluting ones.

The booming cities of China and Southeast Asia face both economic and cultural hurdles to improving energy efficiency -- not unlike their Western counterparts. Fortunately, simple solutions abound: from adjusting building codes to changing the norms of building air conditioning and heating.

Rising gasoline prices, crowded public buses and congested roadways have contributed to the surge in electric bicycles. Last year, Chinese bought 16 million to 18 million electric bicycles, up from 10 million the year before. At least 1,000 companies have sprung up to meet the demand.