People living in south China have been grumbling about gales blowing smog in from the north, as hazardous air chokes more parts of the country this winter. In 2013, China’s smog belt stretched from the developed regions of the Yangtze and Zhujiang river deltas and areas around Beijing and Tianjin, to other places where smog was seldom seen. The southernmost province of Hainan and autonomous region of Tibet recorded smoggy days. Chinese Academy of Sciences issued a report last month about climate change, saying that besides local pollutants, “smog migration” was another serious problem. In Beijing, 30 percent to 40 percent of the PM 2.5, airborne particles smaller than 2.5 microns in diameter, was caused by emissions, 20 percent to 30 percent from chemical conversion in the atmosphere, and the rest from smog movement, according to the report. Meanwhile, according to statistics published monthly […]