First off, carbon dioxide is not a pollutant! It is necessary for life on earth. If you eliminate the CO2 from our atmosphere, all plants will die.
Second, our trucks and cars are mimicking horses. They take in fuel, and oxygen, and emit CO2 and water vapor (and some other products). Cars and trucks are actually much more efficient than horses. If we eliminated all cars and trucks, and attempted to maintain current farm production levels, our new horses would be dumping more CO2 into the atmosphere than our current trucks and tractors... and because horses have to remain alive between jobs, they would do it 24/7. They would also eat us out of house and home, and bury us in dung.
If horses were more efficient than farm tractors, we would be using them right now.
Global warming is a fact. Man's involvement in global warming is purely speculation with a political agenda. Most of the data that is purported to prove man made global warming has had any inconvenient truths that don't support the conclusion conveniently removed.
The number one "greenhouse gas" is water vapor. It is responsible for 95% of the warming that keeps us alive on this planet (Think clouds). CO2 is responsible for 3.5% of the global warming, and humans are responsible for less than 3% of the CO2 put into the atmosphere each year. Nature is responsible for the remaining 97%.
-Chuck