Gywnn Guilford, writing for Quartz about the start of China’s air pollution season in Harbin:
What’s behind the gray-out? Officials blame lack of wind and the burning of corn for the harvest, but the fact that central heating kicked in on Sunday was also a “key factor,” said Xinhua. In Heilongjiang, which is pretty much Siberia, temperatures are already near freezing. And it’s only October. By January, they’ll drop to between -12°C and -24°C (10°F to -11°F), though extreme lows of -42°C (-44°F) aren’t unheard of.
Heating’s a big problem in China. As a study published in May 2013 showed, particulate matter in air north of the Huai River is 55% higher than in the south—and life expectancies 5.5 years shorter. During the 1990s alone, that cost 500 million residents of northern China 2.5 billion life years, said the researchers.