CO2 acts like
the glass of a greenhouse, trapping heat.
«Greenhouse Analogy: Energy from the sun in the form of some ultraviolet and visible light (short wavelength) passes through
the glass of the greenhouse.
The first is the original «invisible something barrier» at the top of the atmosphere, TOA, like
the glass of a greenhouse, preventing the longwave infrared from the Sun from entering, but allowing the mainly visible light to reach the surface and directly heat it and the second is that the Sun produces insignificant amounts of longwave infrared and none of this gets through TOA.
The AGW claim from the comic cartoon KT97 and kin The Greenhouse Effect says that Shortwave, (near UV, visible and near infrared, but mostly visible) heats up land and oceans, that no longwave infrared from the Sun gets through the invisible undefined and unexplained barrier said to be like
the glass of a greenhouse, and then the Shortwave heated land and oceans radiate out longwave infrared, (which in real physics is heat, also called thermal infrared).
They all pass through the atmosphere, but UV can't pass through
the glass of the greenhouse; that is the first major difference.