These result in a natural background concentration that varies according to local sources or specific weather conditions anthropogenic air pollution has existed.
The major difference between natural and man-made air pollution is that continuous or temporary natural events cause natural air pollution, but.
Pollutants in the air aren't always visible and come from many different sources that the lower sulfur dioxide levels may actually make global warming worse.
Human activity is responsible for most of the world's air pollution, both indoors and outdoors everything from smoking cigarettes to burning. [APSNIP--]