Over the weekend, the Beijing-Tianjin-Hebei region in North China, known as Jing-Jin-Ji, saw the resurgence of alarming air pollution. But the air quality has not worsened for no reason. According to experts, the surrounding areas of Beijing are still home to many highly polluting industries such as coal power plants, iron and steel factories, as well as chemical plants. Motor vehicles, particularly heavy trucks running on diesel, are also a major source of pollutants. Statistics show that sulfur dioxide (SO2) emission intensity in Jing-Jin-Ji is 3.6 times higher than the national average, while that of nitrogen oxides (NOX) is four times higher.
In winter, the heating supply, coal burning of households and seasonal stalk burning in Beijing and its surrounding areas emit tons of pollutants resulting in the return of smog. In Beijing, according to the Beijing municipal environmental protection bureau, mobile sources contributed 45 percent of local PM2.5 in 2017. Fossil fuels account for 86.7 percent of China’s energy mix. Last year’s data show that the three biggest consumers of fossil fuels and thus the biggest sources of air pollution in China are industry (64.3 percent), buildings (16.9 percent) and vehicles (15.3 percent).