Critics also raised concerns over long-term dangers, such as subsidence.

"I'm not familiar with the geological features of Changsha, but such a huge building may cause serious problems, even a disaster," Wang said.

A report by the China Geological Survey released this year found that a growing number of skyscrapers are contributing to subsidence in some areas.

Research shows the most vulnerable spots are in the North China Plain, the Yangtze River Delta and the Fenwei Basin, covering a combined area of 79,000 square km - more than 100 times the size of Singapore.

A two-story building sank in Quanhong village in Changsha on Nov 19, Chinanews.com reported.

However, city resident Yuan Zhuang said he is not worried about the potential risks.

"If the world's tallest building is built in my hometown, I'll be proud. It will bring many tourists and boost the economy,"he said.

He added that earthquakes seldom hit Changsha, "which means there's nothing to worry about".

In September, a report by the Council on Tall Buildings and Urban Habitat, an international organization based in the United States, stated that China is planning or building more skyscrapers than any other country, with 239 buildings to be at least 200 meters tall under construction.