In the 1950s, the Chicoms brought in the Haui River policy. The area north of the Huai River receives free or subsidized coal for winter heating. The people south of the river miss out. The line is shown on this map:
From the Proceedings of the National Academy of Science, 2013. As a consequence of the particulates associated with burning that coal, Chinese living north of the Huai River have their life expectancy reduced by five and a half years relative to those living south of the Huai River. Traditionally, stone beds in northern China had coal-burning stoves built into them.
The Chicoms could put scrubbers on all their coal-burning factories and power stations, but they would rather spend that money on building aircraft carriers and other ways to kill foreigners. Killing foreigners has a higher priority in China than clean air and clean water.
Due to the early onset of winter, coal is now in short supply in northern China, and the Xi regime has reacted, in some areas, by banning internal heating until the external temperature falls below -3°C. A lot of people are going to die this winter in northern China due to respiratory failure caused by the ban on Australian coal.
So what is the higher purpose of all this? It is to winkle Australia out of the Quad. The Quad is the grouping of India, Australia, Japan, and the United States formed to counter China's aggression. A few years ago, a Pentagon study concluded that to win against China, the United States just needed bases in Guam and Australia. President Xi must have come to the same conclusion, so he is trying to take Australia out of the picture, and his war is coming soon.