Not wishing to comment on the global climate change here, I just noted that all the links mainly refer to the opinion of the Nobelist Ivar Giaever. It is dangerous to substitute critical argumentation on the actual subject by reliance on opinions of Nobel prize winners. For instance, Giaever's Nobel co-winner Brian Josephson has for years been a strong proponent of parapsychology, and is nowadays not considered very credible within the physics community.
Its good that there are sceptics about the GCC, because the dialog between the opposing views is what makes the scientific progress. But existence of the sceptics is only a starting point, not the proof of validity of the anti-GCC.
Regards, Mikko