Beijing environmental officials announced today that the past six months have seen the clearest air since 2000. They cited less frequent sandstorms and sustained emissions control efforts as the major causes for the improvement in the city’s notoriously smoggy skies. By taking 55,000 of the city’s most polluting cars off the streets, Beijing was able to sustain the addition of 200,000 new vehicles since January without any decrease in air quality, the Beijing Environmental Protection Bureau said.
One factor the environmental officials did not note was the weakened economy. A $586 billion stimulus program and extensive govern-directed lending has enabled China to avoid a severe downturn, and some observers have recently raised their expectations for growth this year. But exports, a major contributor to the country’s economic expansion, have declined since last winter. And electrical output, which contributes to air pollution via power plant emissions, has dropped since September.
The improved air gives Beijing’s environmental officials something to be happy about, but they spent much of their press conference Friday responding to doubts about the veracity of their numbers. Last year an American environmental consultant pointed out that the official numbers showed a disproportionately high number of days that fell just within the official target for a “blue sky day.” Yu Jianhua, head of Beijing’s environmental monitoring center, said the local government used emergency measures such as closing down construction sites on days when it expected pollution would exceed targets. That led to the high number of days just under the cutoff, Yu said.
The U.S. Embassy’s installation of pollution monitor for its staff has raised other questions about how Beijing reports air quality data. The embassy provides hourly readings of fine particulates that are considered especially dangerous to human health. Beijing doesn’t monitor that type of pollutant, and only gives daily readings each afternoon for an average measurement of the previous 24 hours. Yu said that those fine particulates, called PM 2.5, aren’t reported because China doesn’t have a national standard for their measurement. He cautioned that the U.S. Embassy monitor isn’t reliable for broader analysis because it only measures a single location, while the official pollution numbers rely on a network across the city. He wouldn’t say if more timely emissions numbers would be available soon, though as we noted yesterday, China is already doing that for water quality.