What you say might be true for heat input, though, you leave out several other sources of heat.
However, the Global Warming folks are worried about heat output from the earth. The heat input is taken to be a constant. (I know it really isn't, but lets let that slide.)
Carbon dioxide releases are usually taken as the main contributor to Global warming. CO2 isn't really a very good Greenhouse Gas, though it is a weak one. But, most other greenhouse gasses decay into CO2 over time. the exception to this is the main Greenhouse gas here on Earth, that is water vapor. Yes, clouds, haze, good old DHMO, the ultimate industrial chemical, are the major Greenhouse Gas on earth, by over an order of magnitude.