text: To begin with, cars cause a lot of the problems we are having with harmful greenhouse gas. "Passenger cars are responsible for 12 percent of greenhouse gas emmissions in Europe... and up to 50 percent in some car-intensive areas in the United States." (Paragraph 5, Source 1) Greenhouse gas emmisions are extremely harmful to the atmosphere. The greenhouse gases harm the earth's atmoshphere and we as humans, need the atmosphere to protect us from harmful radiation. By limiting car use, you are technically saving the planet and everyone on it.