Wow...Use your head. If I told you to find the temperature of all the CO2 in the Earth's atmosphere, what easily found value could you actually look for that would give you the answer?
The temperature I gave is the average temperature of the Earth. Given that CO2 is a well-mixed gas in our atmosphere, that would be the temperature of all the CO2 as well as the nitrogen and oxygen and every other component. I thought that was pretty obvious but I guess not to everyone.