"As the Paris climate change summit kicks off, China, the world’s leading carbon-emitting country, is choked in pollution. The Ministry of Environmental Protection said Sunday that heavy smog had covered China’s north, including Beijing, for three days in a row. The haze had reached 530,000 square kilometers ( 204,634 square miles) by Nov. 28.
That is even bigger than the total area of Spain, or California.
The air quality index (AQI) for the fine particulate matter known as PM 2.5 had reached 'very unhealthy' or 'hazardous' levels in 23 cities in the combined Beijing-Tianjin-Hebei area and surrounding regions on Nov. 28, the ministry said. At one time on Nov. 29, PM 2.5 in Beijing reached 429 micrograms per cubic meter, 17 times the recommended limit by the World Health Organization. The reading of Beijing’s AQI was still 'hazardous' at 2pm Hong Kong time on Nov. 30, according to air quality monitors."