There is abosolutly nothing wrong with trying to make the world just a bit cleaner. I have two kids, who I hope will never have to eat 3 eyed fish ( think ´Simpsons`). The newer generation of Aeroplanes and engines are much cleaner, queiter and more efficient than lets say DC8/B707 etc, why, because fuel got very un-cheap, lets make another quantum leap, and leave the fossil fuels where we found them, on the ground. Let the greenies scream and shout, Hitler did that, and look what happend to him.
Doc