text: By limiting the amount that the citizens of the United States operate their vehicles, the condition of our environment's atmosphere will improve.  As stated in Source 1, "and up to 50 percent in some car-intensive areas in the United States."  This passage is referring to the amount of greenhouse gas emitted here in America because of passenger cars.  By not using car and taking advantage of other methods of transportation such as buses, walking, and riding a bike that number can be reduced significantly.  In the United States we are also learning from mistakes made by other countries and cities.  "After days of near-record pollution," Source 2 says, "Paris enforced a partial driving ban to clear the air of the global city."  A lesson can be taken from Paris of how we do not want to end up in a situation like that.  By limiting our driving currently we can avoid having to take major steps to clean and clear our environment.  "It will have beneficial implications for carbon emissions and the environment, since transportation is the second largest source of America's emissions, just behind power plants," a sociologist predicts in Source 4.  Environmental advantages of reducing greenhouse gas is a major way we can benifit from limiting car usage.