This is the number one problem I see with the AGW crowd. None of them know that basic Anthropogenic Global Warming hypothesis. They do not know the model requires a 3/1 enhancement of the log warming by CO2. This is also known as the "climate sensitivity number". They do not realize all warming is not caused by CO2. When other global factors are removed from the observed warming, what is left is barely 0.024 deg C/ the expected 2.1 deg C of the log value expected. This way below the margin of error which is +/-0.07 deg C.
I always ask the people spouting AGW hysteria how they stopped natural variational forcings. With that level of climate control, we do not have any problems.