20. BMX Bike — Did you know bicycles can save the world? Motor vehicles are the largest source of ozone pollution which can harm plants and animals… even humans! Motor vehicles also account for over half of all Carbon Monoxide emissions, which contribute to smog and over a third of all Carbon Dioxide emissions, which are the largest contributor to global warming. Half of all trips taken by automobile in the U.S. are three miles or less. If we used bicycles instead of cars for half of those trips we could save billions of gallons of gasoline and tons of emissions from ever being released into the atmosphere. Get pedaling to save our air and the planet!!