Heavy Smog Envelopes China

XI AN, CHINA - FEBRUARY 25: (CHINA OUT) Vehicles are stuck in a traffic jam in heavy smog after the traffic lights were broken-down on February 25, 2014 in Xi an, China. Altogether 1.43 million sq km of China's land territory, nearly 15 percent of the total, have been covered by persistent smog in recent days, according to news report. (Photo by Getty Images)