One among many reasons for AGW skeptics such as myself is the rather large discrepancy in how real data(or lack thereof) is over shadowed by computer models which have been shown to be inaccurate. A BC, Canada university study shows that over 70 computer models that have been used to predict climate changes since the late 70's were inaccurate to the point that statically they were 100% wrong when compared to observed temps from the same period. But then, that's why we call them models, not realities.
Another would be the extremely small data set of accurate instrument read temperatures recorded throughout human history. This data set goes back less than 200 years and yet that seems to be enough for the global warming believers even though planet earth is well over 4,000,000,000 years old.
Like Lenin said...."convenient i..
