text: Cars are very destructive to the enivorment they produce lots of greenhouse gases and create smog. in pairs alone there are about 147 micrograms of particulate matter per cubic meter compared with 114 in Brussels and 79.7 in London said Robert Duffer. Duffer also said cold nights and warm days caused the warmer layer of air to trap car emissions. So to help all these casue go down people are trying to create samller communities like in Vauban, Germany.