Well, it seems that there are at least a few scientists concerned with climate who have actually looked out the window:
"William Gray, emeritus Professor of Atmospheric Sciences at Colorado State University, said that while he believed there had been some background rise caused by greenhouse gases, the computer models used by advocates of man-made warming had hugely exaggerated their effect.
According to Prof Gray, these distort the way the atmosphere works. Most of the rise in temperature from the Seventies to the Nineties was natural,' he said. Very little was down to CO2 in my view, as little as five to ten per cent.'"
