China Is Winning Its War on Air Pollution, at Least in Beijing

China is seeing signs of success in its fight against smog as pollution levels slump dramatically in the capital region Beijing.

Concentrations of PM2.5—the tiny particles that pose the greatest health risks—plunged 33 percent from a year earlier in the fourth quarter across Beijing, Tianjin, and 26 surrounding cities, Greenpeace East Asia said in a Jan. 11 report. Levels in the capital alone tumbled 54 percent. The drops come after government policies last year forced millions of homes and businesses to switch from coal to cleaner-burning natural gas.

The bluer skies came at a price, as the widespread ...