text: "...Passenger cars are responsible for 12 percent of greenhouse gas emissions in Europe... and up to 50 percent in some car-intensive areas in the United States." Cars make up a large amount of the emissions that do harm to the environment. When car usage is limited, less people drive, which in turn limits pollution. "... but also in the developing world, where emissions from an increasing number of private cars are owned by the burgeoning middle class are choking cities." Again we see that cars are polluting our world, and it's caused by us. " it will have beneficial implications for carbon emissions and the environment, since transportation is the second largest source of America's emissions, just behind power plants." Cars and other transporation are releasing emissions which are harming the environment. Limited car usage clears up the pollution which helps us and the environment stay healthy.