text: The gasses that are emmited from cars are very harmful to the environment and can cause serious problems. these gasses get stuck in the in the amostphere, which causes problems like smog in cities. in paris one day they enforced a partial ban on driving because of record breaking pollution the day before. This ban was 2 days and they finned all people with even number license plates. the next day they did the same to odd number license plates. Not only did pollution go down but also "congestion went down 60 percent,"(Duffer).