After Beijing was assured of the 2008 Olympics, the city built subway lines and purchased battery-powered trash haulers and electric-powered buses to further limit air pollution. Pollution from industry was also addressed. Coal-burning facilities were closed and air scrubbers were installed in power plants. Natural air scrubbers in the form of trees -- millions of them -- were planted to aid in removing carbon dioxide from the air.
All of these measures caused the air quality in Beijing to improve 20 percent in a twelve-month period ending in July 2008 [source: New York Times]. Unfortunately, the areas surrounding Beijing were still introducing large amounts of pollutants into the air, which continued to contribute to Beijing's poor air quality.
What is the "food balance factor"?
Answered by Planet Green
How could warmer temperatures affect the weather?
Answered by Discovery Channel
Are there any downsides to electrostatic fuel injection?
Answered by Science Channel