I already have backed up my assertions. You said the material in the references to the wikipedia article was "opinion". I posted some specific material from suppoting footnotes to that article, material that made very specific claims like this:carpro said:
Based on direct analysis of gases found trapped in cores of polar ice, it is known that the atmospheric concentration of carbon dioxide for several thousands of years before 1750 was about 280 parts per million. Between 1750 and 2000, during which industrialisation has occurred, the concentration rose by about 31% to 368 parts per million. The IPCC report noted that the current concentration of carbon dioxide in the atmosphere has not been exceeded during the past 420,000 years and that “the rate of increase over the past century is unprecedented, at least during the past 20,000 years”.
You are now being asked to back up your assertion about this all being an opinion. Are you saying that the above is merely an "opinion"? Did climate scientists sit around in armchairs, sniff the air, and say things like, "You know, it seems to me that the CO2 concentration today is 368 parts per million"?
Or, as I will suggest, did they perform experiments and actually measure this number, as they also measured the rate of increase. Or was that simply an opinion as well?