I dunno...call me crazy...but I'm thinking the temperature on our planet has an awful lot to do with that thing in the sky that we call the Sun! The way these people talk, you'd think that the Sun was a constant.
If these people really wanted to isolate CO2 as the culprit, they'd first need to do an energy balance on the whole, and weed out any variability from bigger contributors like the Sun. Draw a box around the Earth and find out how much of the Sun's energy hits the earth in a given year. It ain't gonna be constant: the sun experiences cycles; some years it burns hotter than others. You've got to eliminate this variability from the equation before we can talk about such minor causes as fossil fuels.
Only surface temperature. Earth radiates more heat than it receives from the sun.