text: Also, the reduction of cars  will reduce the greenhouse gasses being trapped in our atmosphere. "passenger cars are responsible for 12 percent of greenhouse gas emmissions in europe... and uo to 50 percent in some car intensive areas in the united states" (rosenthal 5). This reduction in the amount of cars on the road has bean proven to reduce the amount of greenhouse gas emissions, making our atmosphere cleaner. where there are more cars, there is more greenhouse gas, and vise versa.