cars all around the world are a big part of many peoples daily use. they are used so much that it is starting to become a big problem in major cities like paris, beijing, and new york. now these cities and governments are trying to stop the use of cars before it is too late.

in europe, cars are responsible for 12 percent of greenhouse gas emisions. in the u. s, they are resposible for up to 50 percent in some big cities. if there were less cars on the road, the amount of greenhouse gass emisions would drasticaly change.

in paris, due to the amounts of polution in the air, all cars with even number plates were banned from driving on monday. the next day the same rules aplied to odd numer plates for a 22 euro fine. air polution was down 60 percent after 5 days of intensifying smog.

diesel fuels are blamed in france for causing so much polution. a tax policy there makes diesels more populat than gas cars. diesels make up 67 percent of all vehicles in france, while in western europe, 53 percent are diesel. paris usualy has more polution than other big cities in europe. at one point, paris had 147 micograms of particulate matter per cubic meter. brussels had 114 and londan had 79.9.

recently, there has been a shift in how amercans are usin g there automobiles. as each year passes, americans are buying less cars and driving less. the miles driven in america peaked in 2005 and steadily declined ever since. in april of 2013, the amount of miles driven by a person on average was equal to where it was in january 1995.

in bogota columbia, there acr car free day frequently. in the capital city of 7 million people, only busses and taxis were allowed. authorities from other counties came to bogota to see what i was like without cars and were hapy about it.