Not my colleagues, pilgrim. A lot of water has gone under this particular bridge -- and it's not productive for me to paddle those waters again, tempting as it might be. If you want to continue on the scientific aspects, we can.
Then I suggest you and your colleagues speak to those who do. They are all over the media making outrageous claims and accusations. Even if you had conclusive evidence of a linkage between man's activities and global warming (which you do not), those who claim to represent you in the media and the halls of governance are killing your argument via their hysterical polemics.
Speaking of certainty, the IPSS report claims to be 90% certain that GW is man-made. Does this not give the report a margin of error of 10%? Most scientific studies I have ever seen have margin's of error of less than 5%. That is, of course assuming that the level of certainty is in fact "about" 90%. Given that the actual IPCC report won't be released until May, we can only take the word of the politicians who released the executive summary. How convenient that the IPCC releases the politicians version of the scientific report months before the scientific report can be peer reviewed. That's not the normal peer review process, is it?