I'm staggered that it's becoming a common belief that atmospheric carbon dioxide is responsible for anthropogenic climate change.
Please ask yourself honestly - "Have I diligently looked into the data and science on this, or just listened to the most persuasive argument?"
Our atmosphere is 78% nitrogen, 18% oxygen, 1-2% water (depending on humidity), 1% other trace gases, and 0.039% carbon dioxide.
The thermal conductivity of water vapor is 0.016, The thermal conductivity of carbon dioxide as a gas is 0.0146.
CO2 is therefore 9.59% more effective as a thermal insulator than water vapor.
But there is at any point in time 25.6 to 51.2 times the volume of water vapor in the atmosphere as carbon dioxide. This makes our averaged thermal conductivity between 0.01594 and 0.0157.
If we were to succeed in reducing the CO2 level in the atmosphere to 0.035%, then at any point in time there would be 28.6 to 57.2 times the volume of water vapor in the atmosphere, and our averaged thermal conductivity rage is from 0.01595 to 0.01597.
But, of course, nitrogen has a thermal conductivity of 0.024. And at any point in time there is between 35 and 70 times the amount if it in the atmosphere as the combination of water vapor and carbon dioxide.
Now, if anyone can do the thermal dynamics and tell me what the temperature differential is in degrees kelvin for a movement of 40ppm carbon dioxide, then there is your answer as to how many degrees difference we can expect.
As a red herring (just for the fun of it), if you condense carbon dioxide to the point where it changes to state to a liquid or solid, it actually becomes a refrigerant (-78.5 degrees)... Hmm...