PARIS, FRANCE - SEPTEMBER 27: People riding their bikes down the avenue des Champs-Elysees with the Arc de Triomphe in the background during the car free day on September 27, 2015 in Paris, France. Today between 11am to 6pm Central Paris is to go car free for the day, private cars with petrol or diesel engines are banned and only electric powered private vehicles will be allowed in an attempt to persuade residents to tackle pollution. The event comes two months before the UN climate change conference is due to be held in Paris. (Photo by Aurelien Meunier/Getty Images)
