Why is the smog problem in Shijiazhuang so difficult to solve?

Not only Shijiazhuang, but also the smog problem in the north is more difficult to solve.

The first reason is that the north relies more on heavy industry and emits more pollution.

Second, in the north with frequent smog, heating in winter will inevitably increase pollutant emissions.

Third, it is the geographical and climatic reasons. In many cities in the north, there is little airflow in autumn and winter, and pollutants are not easy to dissipate, so smog will increase.