text: First and foremost on this list is global warming. In Europe, cars produce around twelve percent of greenhouse emmissions, while in the US, the number can be as high as fifty percent in cities. This is not good. Global warming is destroying the ice caps and the ozone layer of Earth, leading to a temperature increase that is damaging many enviornments around the world. This, in addition to pollution released by cars and the oil industry, could permanantly cripple our planet. Any way that we can cut the effects of global warming should be implemented.