Extensive flight delays at Beijing Capital Airport have been cascading since Sunday due to smog. Flights are not expected to resume a normal schedule for several more days or a week.
Chinese authorities say there is no smog, that everyone is mistaken, it is actually fog. However the American Embassy in Beijing has an air quality monitoring station on its roof and recorded that the particulate pollutants have risen to 522 since Sunday. A range of 300 to 500 is considered hazardous, and most average days in Beijing range between 250 and 400 depending on where you stand.
In fact the smog was so thick, visibility had dropped enough that roads had to be closed, including the main road to the airport. Drivers reported they could only see a few hundred feet at most, and in many places, could only see a few cars in front of therm.
China, and Beijing in particular, has been battling the environmental fallout of its policy of production to export at any cost and had to even take extreme measures during the 2008 Summer Olympics and shut down most factories and limit how much Chinese drivers could drive in the weeks leading up to the Olympics.