Do you believe in "Advanced Global Warming"?

Afterall, it is only a theory, and for every person who warns of the devastating affects only a few years in the future, there is someone who can disprove this. But then again, you can’t deny the reductions of sea ice at the north pole and the fracture of ice shelfs in antarctica, and the recent cyclones and weird weather we’ve had. Is this the natural temperature rise that would have happened anyway or is it really accelerated because of us? What are your thoughts? I’m after a healthy discussion here :)