After over a week of mixed pollution, Beijing today outlined emergency measures for fighting smog during the Olympics, potentially expanding what is already the world`s grandest pollution experiment. Under "extremely unfavorable weather conditions," like hot, humid air without the winds needed to disperse pollution, the government may enact further restrictions on factories and cars in Beijing and the nearby city of Tianjin as well as surrounding Hebei Province - in total a region of more than 91 million people.

Instead of removing 90 percent of cars, as proposed earlier this week - or erecting an enormous fan, as has not yet been publically proposed - the rules would maintain the existing alternate-day car restrictions {on even-numbered days, only license plates ending in an even number are allowed to drive} with a further 10 percent reduction: if your license plate number ends in the current date, you`ll need to grab a bike, a bus, a Segway, or ride the city`s newly expanded network.

While the odd-even restriction may be too harsh for most people to swallow on a regular basis, the current date rule sounds like a more practical long-term idea. But are cars really to blame?

It is generally thought that vehicles - especially the older, high emission trucks currently banned from city roads - contribute 40 percent of the city`s smog.

But as Deborah Seligsohn argues at HuffPo, the cars and trucks aren`t the only problem. There`s also the volatile organic compounds {VOCs} from small, sometimes illegal factories operating on the city`s outskirts. 
www.treehugger.com/files/2008/07/beijing-emergency-measures.php