Where does global warming come from?

According to NASA, the sun's radiation, which is what keeps us from being a frozen block of ice like Pluto, has been steadily increasing. See http://www.sciencedaily.com/releases/2003/03/030321075236.htm

This might explain the melting ice caps (I'm referring to the ones on Mars!) Ideally, it should cause those who are willing to sacrifice the economic prosperity of millions in their attempts to prevent global warming to think twice, but that's not likely.