text: To start off, pollution from cars has been a large factor of the air pollution today. In the United States, 50 percent of the greenhouse emissions in the United States is caused by passenger cars. Then there is Paris who has been experiencing heavy smog. Recently, it has had days of near-record pollution. Reason for such high levels of smog or air pollution can be attributed to a tax policy that favors diesel over gasoline. Diesel makes up 67% of vehicles in France. Then in the rest of Western Europe 53.3% of the vehicles are diesel.