Beijing tries to wash smog clean with rain

Beijing is planning to fight the growing haze of air pollution on a new front, using artificial interference measures to dissipate the persistent smog.

Lin Keqing, a vice mayor of Beijing, said at a meteorological conference on Tuesday that the city will launch experiments on artificial elimination of smog and haze to improve air quality, reported the Beijing News.

The move is in response to a recent initiative issued by the China Meteorological Administration that requires local weather bureaus to improve their capabilities of magaging air quality through artificial weather interference by 2015.

There are two ways to reduce smog, artificial precipitation and artificial haze dissipation, according to Guo Xueliang, director of the weather modification center under China Meteorological Administration.

The artificial creation of rainfall has already been applied in many places across the country, mainly as a way to fight drought in the past, the People's Daily quoted Guo as saying.

Rainfall is effective in driving away haze, Guo said, but the necessary weather conditions are needed. Also, if the smog is mainly dust and smoke in the air without moisture, there will be no effective measures to take away the pollutants.

Wang Gengchen, a research fellow with the Institute of Atmospheric Physics at the Chinese Academy of Sciences, has his doubts over the new methods to fight air pollution.

"As the pollutant particles are thick and cover very large areas, the effect of artificial rainfall on eliminating the smog and haze is very limited," he told the Global Times on Wednesday.

To effectively dissipate smog, artificial precipitation needs to be created at considerable cost, Wang added.

In Sichuan and Beijing, experiments have been conducted in using liquefied nitrogen to change fog particles into heavier ice crystals, reports said.

Local authorities have been pushing ahead with the ambitious weather interference measures, some even joining hands for cross-region operations.

In November, a working team involving Beijing, Tianjin, and nearby regions was established to work on solutions.

But Wang said that even if artificial rainfall modification can work, given enough investment, under the ripe conditions for rainfall, it will not ease the air pollution due to frequent air movement, which can bring in pollutants from elsewhere.