"Before the conference, [supporting a] low-carbon economy was political risk; after the conference, it has become an opportunity," Zhuang said.

Experts say guidance from the central government is absent. The National Development and Reform Commission worked on guidelines for the development of a low-carbon economy in March 2009 but has yet to produce a final version. Instead, China's economy planner has passed the responsibility to local governments, rolling out a pilot program in August that calls for five cities to set their own concrete targets and measures for greenhouse gas emissions.

But not all plans are necessarily good plans. Hebei Province's Huailai County recently widened its main street to 24 meters in a move to become China's first zero-carbon town. Jiang dismissed the plan as a "gimmick."

"The new road is too wide for a city with a population less than 200,000," Jiang said. "Some cities are too radical."

With no real idea of how to transform cities into low-carbon societies, the central government hopes such pilot programs will foster experiments that will eventually lead to a solution. But the cities don't always have the ideas and are used to relying on the central government for guidance. Advocates for low-carbon cities hope the target cut for greenhouse gas emissions will be written into the 12th Five-Year Plan, but even then, much work remains to map out a way to meet the target.

"Building a low-carbon city should be more a responsibility than merely paying lip service," Jiang said. "The real meaning of low-carbon city lies in improving the living environment, ensuring energy security and sharpening clean technologies."

Jiang is attending side meetings of the ongoing UN climate talks in Cancun on low-carbon cities in hopes of gaining ideas from other countries.