text: Cars are part of the reason that our environment needs constant monitoring. Transportation is the second largest source of America's emissions, only behind power plants. Our polluted air is mostly made by all of the smog that cars create. Even every-day citizens have taken a step in helping our environment. According to Source 3: Car-free day is spinning into a big hit in Bogota, A businessman, Carlos Arturo Plaza, stated that "It's a good opportunity to take away stress and lower air pollution." This shows that the problem our environment is facing has even caught the attention of ordinary people. Smog has also become a big issue due to the excessive driving of cars. According to Source 2: Paris bans driving due to smog, "After days of near-record pollution, Paris enforced a partial driving ban to clear ther air of the global city." This evidence suggests that excessive smog has become such an issue that now driving has to be banned in order to help our environment, even if just temporarily. The increasing concern for the well-being of our environment has been directly blamed to the use of cars.