text: Let me explain. If almost everyone on this earth has a car, some have 2 or more or some dont have any, and if there is 7 billion people on this earth. Do the math, thats around 14 billion cars driving around, and eatch one of those cars give off exsost that hurts the enviroment. The earth has a layer ever it called the ozone layer and protects the harmfull sunrays from hurting life on earth. But with cars driving around that hurts the ozone layer.