text: Paris once had suffered for a few days because of the cause of pollution. The troops stationed there had enforced a partial law to ban driving, to clear the air of the global city. On a Monday, each motorists with even-numbered license plates were given two options. To leave their cars at home or suffer a twenty-two euro fine. This rule was also appointed to the odd-numbered plates the following day. Arond four thousand drivers were fined, and their vehicles were impounded. They say that Diesel fuel was to blame. The colder nights and warmer days had caused the warmer layer of air to trap car emissions. France has a policy that favors diesel over gasoline.