I think vehicles that are loaded with smog devices that reduce fuel mileage and engine performance are contributing to smog and global warming. Twenty years ago, there were cars that got 50 miles per gallon. What happened?
If vehicles got double the mileage, the following would happen: the oil being pumped from the earth would be cut in half, the number of barges shipping the oil around the world would be cut in half, the emission from refineries would be cut in half, the number of railcars carrying the oil across the U.S. would be cut in half, the number of diesel fuel tanker trucks transporting the gas across the U.S. would be cut in half, the number of people waiting in line with their engines running at gas stations would be cut in half.
If you look at the big picture, of course it's the thing to do. Thomas Edison would have figured out the whole electric car thing by now. But he's gone and the average person seems to be the only intelligent life form left. Or could it be the money involved that's causing all the rich, important and brilliant people to draw a blank.