text: The main culprit of pollution issues is car usage.  In Source 2, Robert Duffer says that "Diesels make up 67 percent of vehicles in France..."(Duffer 16) This is because of a tax policy that has a preference to this fuel.  Diesel fuel is a lot more harmful than regular gasoline, and if many people are using this fuel pollution rates will skyrocket.  Cutting down on these fuels altogether could create a less polluted environment.  In addition, cars cause 12 percent of greenhouse gas emissions in Europe, and 50 percent in specific places in the U.S(Rosenthal 5).  This statistic is startling, since half of the pollution problems in the U.S are associated to cars.  By using other means of transportation such as the train or even carpooling, this number can be greatly reduced to a much smaller percentage.