>>12464753>Isn't space already a very good insulator?It's a good insulator in the context of conduction. This is irrelevant for the Earth's heat flux, which is purely radiative. CO2 let's in all sunlight but when that sunlight is turned into radiative heat, it prevents some of it from radiating into space. It's very common for people to get confused since conduction and convection are the main methods of heat transfer at Earth's surface. But they don't determine the amount of energy at the surface.
