Experts concerned by differing views on pollution's source
A ban keeping half of the city's vehicles off the road during Beijing's first red alert last week caused the concentration of major airborne particles to drop by some 14 percent, doing little to eliminate the smog blanketing Beijing, media reported on Monday.
The news came amid a flurry of conflicting views about the source of the hazardous smog that choked North China, confusing the public and causing analysts to worry about the government's future measures to tackle heavy pollution.
The Beijing Municipal Environmental Protection Bureau upgraded an orange alert to red on December 7. The upgrade activated emissions reduction measures, including shutting down factories and instituting an odd-even license plate system halving the number of vehicles on the city's roadways.
Local environmental protection authorities announced on Thursday that measures under the red alert slowed the accumulation of pollutants and lowered the overall pollution level.
The reduction of nitrogen oxide discharged by vehicles led to a decrease in nitrates and sulfates, two main components of PM2.5 - particles with a diameter smaller than 2.5 micrometers - said Wang Yuesi, a researcher with the Chinese Academy of Sciences (CAS), as quoted by China Central Television.
"Vehicle emissions are a key cause of air pollution, but they are not the main cause for the smog in Beijing," Ma Jun, director of the Institute of Public and Environmental Affairs, told the Global Times on Monday.
After the first red alert for heavy air pollution was issued, several government departments attributed the smog to different sources.
The Ministry of Housing and Urban-Rural Development said in an interview with the People's Daily that "winter heating was only the last straw that crushed the air quality." Meanwhile, the Beijing Municipal Environmental Monitoring Center said that coal burned for heating was the primary culprit behind the smog.
"Differing views about the smog's sources reflect a lack of coordinated efforts to tackle hazardous pollution," said Ma.
"Different departments focus on their respective governmental functions to monitor and analyze the sources of smog, and different local governments tend to focus on the pollutants generated locally while excluding transmitted pollutants."
The results of analysis are thus inaccurate and incomplete, Ma said, adding that authorities must take a cross-regional view of pollution.
China National Geography reported in November 2014 that wind power generation projects in North China's Inner Mongolia Autonomous Region may slow down wind speeds and worsen heavy air pollution in Beijing and Tianjin.
Wang Gengchen, a research fellow with the Institute of Atmospheric Physics at CAS, disagreed with the report, saying that the smog is due to urbanization in the region.
"The severe smog in Beijing is linked to regional air pollution: Coal-burning pollutants and industrial pollutants from Tianjin and Hebei Province were transmitted to the capital," Wang told the Global Times.