Cloud cover?
Cloud cover or not, the earth's atmosphere will still absorb the solar energy (heat) from the sun. And if the percentage of Co2 in that atmosphere is higher, relatively, more heat will be held.
Seriously, you are trying to somehow deny the most basic of physics. Have you any scientific background at all, or are you just being hard headed?
Later and Best, bulldzr
"So often times it happens, that we live our life in chains, and we never even know we have the key."
-The Eagles