Based on Beijing Municipal Environmental Protection Bureau\u2019s study in 2017, transport typically makes up 45% of the pollution we breathe, and with a drop in traffic up to 70%, we’d expect a drop in pollution levels. However, even if we remove transportation emissions altogether, and perhaps half of industries, we would still have more than half of usual PM2.5 pollution, that would accumulate rapidly when wind converges towards a region. That is what happened to Beijing.<\/p>\n