Even so, pollution levels fell less precipitously or rose elsewhere, suggesting that a concerted effort last fall to shift heating to natural gas from coal may have simply shifted the harmful effects to regions far from the capital.
In the northern province of Heilongjiang, on the border with Russia, pollution levels rose 10 percent. In a statement with its analysis, Greenpeace argued that the results demonstrated the need for more government action, noting that nationwide the drop in pollutants was only 4 percent.
“China’s national air pollution action plan has brought massive reductions in pollution levels and associated health risks, but policies favoring coal and heavy industry are holding back progress,” Huang Wei, one of the organization’s campaigners, said in the statement.
But in Beijing, where pollution levels are tracked as closely as property prices are in Hong Kong, London or New York, the respite from eye-watering, throat-scratching smog has nonetheless been welcomed. Only a year ago the pollution was so bad on some days that schools were closed and flights were canceled.
Air quality is measured by the concentration of PM2.5, or particulate matter of a size deemed especially harmful; such pollutants contribute to a variety of health conditions. Anything under 50 is considered good.
For a couple of days at the end of December, levels nearly reached 300, which is considered hazardous, but those were, for this winter so far at least, the exceptions. (On Thursday evening, as this article was being written, the level was 29, according to the China Environmental Monitoring Station index.)
But beyond the health risks, pollution also poses a political risk for the government of President Xi Jinping as he moves to promote the country’s rise on the world stage.
The government does not seem to be resting on its laurels in the fight against pollution. The Ministry of Environmental Protection warned in a statement on Wednesday that clearer skies were caused in part by favorable weather conditions, and that conditions could worsen in late January and early February.
“Local governments need to strengthen pollution controls to further cut emissions and make sure they reach their goals on air quality improvement,” the ministry was quoted as saying in China Daily.