Why does smog occur in Beijing?

There are three main reasons for this heavy pollution.

First, coal burning, motor vehicles, industry, dust and other pollution sources emit large amounts of pollutants, which are the root cause of this serious air pollution. Especially since December 2012, the entire North China region has been experiencing extremely low temperature weather. Due to the low temperature, coal-fired heating emissions have increased correspondingly, and the impact in this regard is relatively large

Second, the diffusion conditions are unfavorable. The recent extremely unfavorable pollution diffusion conditions are the direct cause of this pollution process.

From the 10th to the 13th, the ground in the Beijing area was closed and under low pressure control, the surface wind speed decreased, the humidity increased, and the extreme weather of incoming wind inversion and heavy fog gradually formed, and the continuous accumulation caused this pollution process;

Third, the contributions of regional pollution and local pollution are superimposed. The regional nature of PM2.5 pollution and the transmission of related regional pollution are also important factors in the formation of this heavy pollution