Here is an example of "we're improving".

There is a city outside of Houston called Pasadena, often called by Houstonians as Pasa-git-down-Dena or Stink-o-Dena. It's a blue-collar town, former home to the local chapter of the KKK, a drive-in XXX theater, and a number of refineries and other chemical plants. For years was one of the worst-smelling places around - hence the name "Stink-o-Dena".

When I resumed civilian life in 1987, I had to make the odd trip down there, which continued until a couple years ago. Lo and behold, the chemical plants and other polluter facilities had cleaned up their act. It was possible to go to Pasadena at just about any time of day or night without having an asthma attack. Plus the KKK had finally buggered off.

Pasadena is still not my choice of place to live, but is nowhere near as polluted as it was in the 1970's through early 1980's.

I'm not going to defend Hummer drivers, as a class I think they are morons who have way too much money and not enough sense. But the US has made great strides in pollution control over the years, and does not warrant the slapping you and Metin seem to want to give us.