bio-diesel
The least expensive mode of transportation is by water. It is fuel efficient, less polluting and the safest. It is also the least expensive to move cargo.
tatti
Natural gas releases less carbon dioxide pollution when burnt than either coal or oil.
diesel
gasoline
Jet fuel is capable of polluting, just as gasoline is.
It's a car that only runs on electricity so you are not polluting the environment with the gas exaust
hydrogenA2:Coal is the fuel that produces the least pollution among the choices. Hydrogen would be the least polluting except for the reality that hydrogen is produced by burning coal to produce electricity to electrolyse water. Only if the electricity used to produce the hydrogen were produced by hydro, wind or solar, would hydrogen be less polluting than coal.
Yes people are polluting their water with oil or fuel
By using cycles instead of polluting vehicles.checking the condition of your vehicles
Mass - the heavier the vehicle, the higher the fuel use as a general rule. An aerodynamic design will reduce wind drag and also reduce fuel use. Electric vehicles will generally be non-polluting - very useful in a city environment as no smog will be formed
By closing down factories that produce polluting gasses, by not using vehicles that produce such gasses ether by making it illegal or by finding a fuel that can be used by such that do not result in air pollution.