Bao said smog and haze should be viewed as a type of meteorological disaster, because it only occurs under temperature inversion, when the bottom of a layer of air is cooler than the upper layer, preventing the air from natural interchanging, thus blocking pollutants from dispersing.

"The air in that condition is so stable that it's like covering a city with a lid," said Bao. "Pollutants can neither go out, nor come in — that's why smog and haze cannot be prevented by regional joint prevention and control.

"What we can do is to gradually cut the pollutants' concentration in smog and haze by taking care of each region's problems, including pollution from automobiles for Beijing, construction sites for Tianjin and burning coal for Hebei province," he said.

At a national environmental conference in late January, Environment Minister Zhou Shengxian said the government is striving to control all cities' PM2.5 levels within the national standard by 2030.

Though the public appears unsatisfied with the timetable, experts say the target may already be hard to reach.

"We can't prevent smog and haze even by 2050, because the weather conditions are not within control," said Bao. "But we may reduce the pollution level during smoggy days from 'heavily polluted' to 'medium' or even 'slight' after 10 years' efforts. Meeting the daily standard of 75 micrograms per cubic meter by 2030 may not be realistic, but we have a good chance of reaching the annual standard of 35 micrograms per cubic meter."

Bao also said the ministry may set up a special fund to control airborne pollution before 2014. The amount of money invested is expected to be similar to that in a special fund for water pollution several few years ago — more than 1 billion yuan ($160.6 million) — and a considerable proportion will be spent on scientific research.

"Before implementing regional joint prevention and control, we have to find out exactly how much pollution cities and provinces are contributing to their neighbors, which is still not clear," Bao said, adding that the investigation and monitoring of PM2.5 in China is still at an early stage.