text: To continue the advantages, passenger cars are responisble for 12 percent of greenhouse gas emissons in Europe. Beijing and china are well known as one of the most polluted cities in the world. In the suburbs, where middle-class families from Chicago to Shanghai tend to make their homes makes a huge impediment to current efforts to drasticallyreduce greenhouse gas emissions from tailpipes, experts says. Cold nights and warm days caused the warmer layer of air to trap car emisson.