I think the problem is deeper then just driving cars. We have had glaciers in the North Artic for thousands and thousands of years, and they are predicted to be gone in the summer months 25-30 years from now. I think we have contributed to the warming of the Earth. I mean, it only seems logical if more gas is released into the atmosphere then what is naturally supposed to occur. If I fill a bowl of water with water already in it, it is going to eventually over fill itself. That's just my 2 cents