Traffic moves through dense smog in Beijing.

Air quality is hitting hazards levels as people brace for a long winter

Beijing suffered a smog emergency last winter and many fear that such conditions could return.

Authorities are hoping for relief Sunday expecting high winds to provide relief.

Meanwhile fog is blanketing much of northern, central and eastern China.

China is the world's biggest greenhouse gas emitter and is heavily reliant on coal.

As winter comes air quality could get worse with public heating systems offering relief from the cold -- while adding to the smog.