Could you understand that they saw the facts before the warmers altered things and refuse to accept the manipulated numbers. How would you feel if you sat in on a card game and refused believe they guy who told you the deck was stacked and not to play. Well the deck has been stacked with marked cards by a bunch of sharks and you either play their game or you sit on the side and kibbutz like we skeptics do to keep more people from being taken in by the sharks.
Maybe the core of the determination is because there are two clear and concise statements on whether co2 can truthfully be called a greenhouse gas. One by the followers of Svante Arrhenius who derived their co2 sample using water and acid from limestone and then used water to test for the presence of co2 say yes. Those who follow Knut Angstrom that used dehumidified co2 for his experiments say co2 is such a minor green house gas that it should not be considered to have an atmospheric warming effect. So Arrhenius says co2 is the major driving force and his followers believe this. Angstrom documented that water vapor is 99.99% of the green house effect and his work verified through the scientific method for 100 years is why most skeptics take the stand that the minor warming we have had over the last 150 years is natural with minimal contribution from industry if any.
So either you believe the peer reviewed opinion of Arrhenius that says humans did it or you have seen the experiments validating the laboratory work of Angstrom and realize co2 does not have the capability of contributing to warming unless local humidity is abnormally high.
