> Global warming or not, no one can argue with the fact that air quality in large cities in US, India, and China is atrocious. You can argue with that for the

> Global warming or not, no one can argue with the fact that air quality in large cities in US, India, and China is atrocious. You can argue with that for the US. "atrocious" compared to what? It's certainly a lot better than it used to be. > And that pollution is 100% man made, no argument about that. Not 100%, no. Some of our pollution is nature-made. Los Angeles was smoggy before there were any cars there - the Chumash indian tribe called Los Angeles basin "the valley of smoke". It has environmental conditions conducive to collecting particulates in the air - even pollen and dust and wood smoke from natural fires will collect and form a lingering haze there.