Regardless, that's not the way that even the warmers claim that greenhouse gases work. You're constructing a straw-man for the warmers to have fun with.
Carbon Dioxide irrelevant in climate debate says MIT Scientist"More simply put, the UN results illogically predict that as the oceans got warmer, the earth would simply hold more heat. The UN explains that it is CO2 which is holding this extra energy. This theory is not supportable by the simple fact that CO2 cannot hold that much heat, it is a very poor greenhouse gas compared with water."