We know the absorption bands for CO2 and CH4, as well as the other GHGs that we are creating. We have data from satellites that show less energy being emitted from the earth in those bands. Therefore, we are retaining the heat that would have otherwise been emitted.
We also know that the emission bands are the precise opposite of the absorption bands indicating that no energy is being trapped by so called greenhouse gasses. As to satellites showing that less energy is being emitted from the earth in those bands, I call bullshit. I have provided snapshots of those satellite data and they show no decrease in energy in those bands even though the concentration of so called GHG's has increased. The only thing that showed less energy as a result of so called GHG's was the models. Once again, you guys are accepting the output of models as actual data. That is the primary reason you can't be taken seriously.
‘The satellites show cooling’—No, they don’t | How to Talk to a Climate Skeptic: Responses to the most common skeptical arguments on global warming | Grist