text: To begin with, out of all the good cars do for us they also do some harm by polluting the atmosphere and the Earth. Passenger cars are responsible for greenhouse gas emissions in Europe and some areas in the United States as cited in source 1. Long term car usage causes smog which happened in the capital of France which caused car traffic to go down 60 percent which is found in source 2. Cold nights and warm days caused the warmer layer of air to trap car emissions as found in source 2.