CO₂ is carbon dioxide and is what is being related to global warming. Plants and trees take in the CO₂ and produce oxygen for us to breath. CO without the extra oxygen atom is carbon monoxide which you get from running a car and burning fossil fuels. Granted running a car in a garage is not a good idea but the world's garage is so large that it would probably take thousands of years before we would choke to death from the pollution. As was said above there is a difference between global warming and pollution. The Earth goes through warming and cooling cycles naturally since it's creation. Right now we are on the warming side of the cycle and there is nothing to be alarmed about, we will swing back to cooling, albeit many many years after we are dead and dust in the Earth. I believe this global warming scare is simply a method to frighten people into forcing the research into alternative fuels. Which is a good idea to find alternative fuels but the end does not justify the means.