Restoring the blue skies

The bad news about air quality in China is well known. Almost every winter, as temperatures cool in the north of the country and homes need to be heated, China makes headlines around the world for the poor quality of its air. A particularly bad episode last December was dubbed Airpocalypse. During Airpocalypse, several cities in northern China reported air pollution readings that were off the scale. Hundreds of flights out of the capital, Beijing, were canceled. Schools were closed. And municipal governments declared a red alert on the smog, which affected nearly 500 million people. More recently, in May, vehicular and industrial emissions combined with a sandstorm to again send pollution levels off the charts in Beijing. But the headlines and ominous pictures distract attention from a positive trend. Chinese authorities are doing more and more to control air pollution, and the effort is starting to pay off. Despite