text: By limiting car usage, the amount of greenhouse gasses- gasses produced by exaust, carbon dioxide, etc.- would be reduced. Greenhouse gasses effect the ozone layer of the earths atmosphere and that in turn effects the health of everyone breathing in the earths oxygen. Greenhouse gasses, albiet the healthy sounding name, is not good for people or the enviornment. By limiting car usage, people can put a dent in the amount of greenhouse gasses being produced. "Passenger cars are responsible for for 12 percent of greenhouse gas emissions in Europe... and up to 50 percent in some car-intensive areas in the United States" (5) This means people can change the world by simply reducing their car usage.