The famous Chinese smog
Astonishingly, those days were a measured improvement over what my parents experienced. The smog used to be thick enough to obscure the sun completely, turning the daylight into a diffuse glow. Sometimes, it blocked enough of the daylight to create a sort of murky twilight. Here is the first known photo of LA's smog, from 1943 :
Beijing is like that, except the mantle of smog is much, much wider than the one that covered Los Angeles in its worst years. For the Olympics, China has been working to improve the situation, but the progress so far is not very impressive. Days with good air quality, called "Blue Sky" days, would be emergency smog alerts in Los Angeles. The Beijing Air Blog has some interesting data on China's ongoing battle with air pollution, though there haven't been many posts in a while. Here is Tienanmen Square on April 27, 2008, which was officially a Blue Sky Day :
The smog extends pretty far from the city. This is the shot from a train window about a hundred miles north of Beijing. The factory (refinery? LNG plan? cement factory?) is only about a mile or two away, and it's almost completely invisible.
I'm not going to delve into why this is a bad thing. Global warming, cardiopulmonary disease, lead, mercury, yadda yadda. You already know the arguments, or you can make your own. Here's a reason that doesn't require any sort of scientific background to understand. The day after I took the photographs above, a heavy thunderstorm scrubbed the smog out of the sky. This is what China is supposed to look like :
China is a damn beautiful country, when you can see it.