After years of complaints about environmental standards, China has agreed to change the way it measures clean air.
On Nov. 10, the Ministry of Environmental Protection (MEP) said it would try to tighten its rules for measuring fine particles that often darken the air in Beijing, despite official reporting of "blue sky days."
Environmental groups have argued for years that China's reporting paints a rosy picture of pollution because it counts only larger particulates, or particles of soot.
World Health Organization (WHO) guidelines call for measuring particulates as small as 2.5 microns, or thousandths of a millimeter. But China's standards stop at 10 microns, capturing only the large particles.
The difference allows cities like Beijing to claim they have "blue sky days" for much of the year when the air is clouded by curtains of grit.
"This is an interesting concept in China, the blue sky index," said Kevin Jianjun Tu, a senior associate at the Carnegie Endowment for International Peace. "It has nothing to do with blue sky."
Last year, the capital counted 286 blue sky days, easily topping the government's target of 266 days, according to official figures cited by the environmental website rawsep.wordpress.com.
But a dismally dark week in November and scathing criticism from Chinese bloggers have persuaded the authorities to drop the pretense.
On Nov. 17, the MEP said it is now "gauging public opinion" on the tougher measuring standard, known as PM2.5, the official English-language China Daily said.
2016 target date
The agency is also seeking to cut 10 percent of the smaller particle emissions in cities and industrial regions by 2015, the paper said. But the new standard would not be implemented nationally before 2016.
Speaking to students at an exhibit in Beijing, MEP Vice Minister Pan Yue apologized for the government's performance, saying that "we feel ashamed of what we have done and we are trying our best to improve the environment."
The new push has been driven in part by hourly air quality bulletins posted by the U.S. Embassy in Beijing on its Twitter account from rooftop monitoring gear.
The equipment frequently reports "hazardous" readings when the city calls the pollution "moderate" or "slight," The New York Times said. The embassy's postings are at twitter.com/#!/BeijingAir.
The local authorities have tried to ease public anger by offering limited tours of their monitoring facility.
Speaking to RFA by phone from Beijing, Tu cited growing skepticism among the public and the media.
"The government has started to feel the pressure. That's why it wants to tackle the challenges in the future," he said.
In an unusual response, the official Xinhua news agency started reporting daily air quality results for 47 cities on its English-language website, but the postings have not specified the particle size.
Some of the public anger stems from visible pollution, which often contradicts the official reports. But unseen health effects of the smaller unreported particles are also "more dangerous" because they can lodge in the lungs, according to the WHO.
A World Bank study in 2007 blamed China's urban air pollution for 350,000-400,000 premature deaths per year.
On Nov. 4, the Times also reported that many homes and offices of China's top officials have been equipped with air purifying machines costing some $2,000 (12,690 yuan) each.
China has used the blue sky index for years to argue that urban air quality has improved. The number of blue sky days in Beijing has grown steadily from 177 in 2000, according to the website www.livefrombeijing.com.
Reporting the real conditions may be the first step toward actual improvement. But Tu noted that the finer PM2.5 particulates are harder to control, since they include not only coal soot but also auto exhaust and even cigarette smoke.
China's surge in coal consumption over the past decade is its biggest air pollution problem. The country now burns more than three times as much coal as the United States.
While China's per capita energy use is still far lower than U.S. levels, it uses five times as much coal per unit of GDP as the world average, the International Energy Agency (IEA) said this month in its annual outlook report.
In 2035, it will still be using more than twice as much, the IEA said.
Air pollution from automobiles will also be hard to control. Annual sales of private cars have soared from less than 1 million in 2000 to 14 million last year, when China surpassed the United States, the report said.
But that may be only the beginning.
By 2035, car sales are projected to reach 50 million, the IEA said, although ownership rates will still be less than half the level in the United States now.