text: As of recently, the impact that cars have on the enviroment has gained more attention as well as increased concern. All vehicles emit greenhouse gasses, which are very harmful to the enviroment, causing smog and damage to the atmosphere. According to source one, limiting the use of passenger cars could reduce total greenhouse gas emissions by up to 50 percent. Source two describes how the accumulation of smog in Paris became so bad that it caused official bans on the use of cars. It took an entire week of restricting car usage to get the smog to clear up. Source four also agrees that the results of limiting car usage would have beneficial implications for carbon emissions and the enviroment. Source one mentions that as a result of all of this, the Enviromental Protection Agency in the United States is promoting car reduced communities.