text: ", we are told clearly that, "Passenger cars are responsible for 12 percent of greenhouse gass emissions in Europe... and up to 50 percent in some car-intensive areas in the United States. "  This may seem like very little, but with the amount of cars in the world, these numbers add up to staggering damage to the enviroment.  Robert Duffer wrote an essay telling of these harmful effects in a shocking way: "