It's actually true what Fkeu is saying. Talk to a geologist. He'll tell you, that for the majority of the earths existence, there hasn't been any icecaps at all! Personally, i'm not supporting the whole "humans cause global warming" thing. i'm more of a follower to Henrik Svensmark. (see bottom). There has been times in the history of the earth, where there has been twice as much CO2 but it was much colder!
That being said, it doesn't justify the deforestation or just the general poor caer we put into our beautiful planet.
http://www.youtube.com/watch?v=ANMTPF1blpQ i know it's long and that he has a horrible accent