The US and Western Europe burn far more fuel today than they did in the 1960s, but have vastly cleaner air than they did then. Efficiency and reduction of use a

The US and Western Europe burn far more fuel today than they did in the 1960s, but have vastly cleaner air than they did then. Efficiency and reduction of use are not sufficient to improve air quality. In fact, big diesel engines and big coal fired power plants can be some of the most efficient methods of using energy while still being tremendously polluting. The problem is primarily particulates, sulfur, NOx, and carbon monoxide, all of which can be controlled if the proper systems are used.