It's a natural occurrence. The funny thing is, a lot of scientists actually believe we are at the beginning of a mini ice age rather than a warming period.

Most of the facts about global warming are bold face lies or misrepresentations in order to promote their agenda. The ice caps for instance are actually getting thicker with the exception of one that is melting.

It's all a money making attempt, they had a product (green energy) I'm talking to you Gore, but not a market. Therefor they had to create a pseudo-science in order to build demand for their products.

If your interested, read State of Fear by Michael Chricton. It is a work of fiction, but the global warming facts he uses are accurate and he provides a list of citations to back everything in the book up.