text: have you ever heard of the greenhouse affect, global warming and air pollution? the abundant usage of cars have a large affect on those vital things in our environment . In cities like paris , because of the air pollution caused by cars, there is very dense smog ( source2 ). Air pollution is very important because the toxins in burnig fuel can be harmful to the healthof citizens. smog is not only a problem in paris , but all over the world . places like paris and Bogato have created things like car day , to discourage th e use of cars, because of that the air polluston on these places have reduced dramatically .(source 2 and 3). due to the efforts to reduce car usage , the smog and othe pollutions clearded up uthe air which showed that not using your car for one day can be tramindasly helpful to your environment.