but there are many things that increase greenhouse gases (including methane gases from cows, decaying and plant decay). The earth has gone through cycles of cooling and warming throughout history...that would suggest that cycle is normal. In fact all the hype with the media in the 70's was "global cooling" (Newsweek 1979) Here is a link to a bunch of news articles that illustrate how the fear keeps going from cooling to warming.
The idea that our current increase in tempature (less than one degree F by the way) is the result of man's activities is complety a theory and is currently more political than scientific.
