text: Pollution is an large issue in todays world. According to Rosenthal in source 1, "passenger cars are responsible for 12 percent of greenhouse gas emissions in Europe... and up to 50 percent in some car-intensive areas in the United States (P5)." The use of cars has created smog in many large cities. The 2009 Olympics in Bejing required the city to reduce car usage in order to clear the air. Those participating and attending the event were in danger of harming their lungs. The citizens of Bejing has already been noted to wear respirators and other devices to filter the toxins from the air they breathe. In this extreme case, it was manditory to cut the usage of cars down. But in other cities, they have not reached this extreme and it can be easily prevented by limiting car usage. Duffer mentions the pollution in the skies of the global city of Paris has been noticably decreased(P19). In another scenario of pollution in the atmosphere, the city has taken initiative to ban cars depending on the number of their license plate. Without the emissions from the cars, the air would be clean to breath and a better sight as well.