To follow up my last post, probably the best place for informed debate about global warming is at the realclimate site below. This site was set up by a group of very renowned climate scientists to allow an open dialogue about the science of climate change.
I suspect that this is the best source of information outside of the dedicated scientific press.
http://www.realclimate.org/
Hope you find it useful and interesting (and a little eye-opening...).
Dr D.