> That's what causes extra warming of the surface compared to the situation without air.
While this effect may be real, it's not what people are referring to as the "greenhouse effect". This requires the absorption and re-emission as IR. Methane and CO2 are considered greenhouse gases because they absorb thermal IR, not because they absorb reflected light from the surface.
In addition to the Wikipedia article machina_ex_deus linked, this might be a good intro: http://forecast.uchicago.edu/archer.ch4.greenhouse_gases.pdf. I'm not sure if I buy all of machina_ex_deus's conclusions, but I think his description of the effect is much closer to accurate than yours.
While this effect may be real, it's not what people are referring to as the "greenhouse effect". This requires the absorption and re-emission as IR. Methane and CO2 are considered greenhouse gases because they absorb thermal IR, not because they absorb reflected light from the surface.
In addition to the Wikipedia article machina_ex_deus linked, this might be a good intro: http://forecast.uchicago.edu/archer.ch4.greenhouse_gases.pdf. I'm not sure if I buy all of machina_ex_deus's conclusions, but I think his description of the effect is much closer to accurate than yours.