text: , anywhere up to 50 percent of car-intensive areas in the US make up the greenhouse gas emissions. It is depressing seeing all of this smog and polution in the air everyday. Just a little heads up but the polution increases every single day we use cars. It is a shame seeing such an extravogant and extraordinary country go to crap due to polution. If you want to see how every state is going to look if we keep relying on cars then go to California and see how much of an eye sore it is. Cars are one of the major factors responsible for smog and polution. Polution from your car can lead to animals dying and especially humans dying from your automobile.