How Long Is Carbon Dioxide Half Life?

Carbon dioxide has a half life of about 120 years, methane 10.5 years, nitrous oxide 132 years, and the CFCs 16 to more than 500 years, as shown in the accompanying table.

How long is CO2 half life?

The half life of ~27 years is equivalent to a residence time for CO2 of 39 years. A major conclusion of this post, therefore, is that emissions can be fitted to the observed evolution of the atmosphere using a single time constant model that has a 2.5% per annum decline rate.

How long does carbon dioxide remain in the atmosphere?

Carbon dioxide is a different animal, however. Once it's added to the atmosphere, it hangs around, for a long time: between 300 to 1,000 years. Thus, as humans change the atmosphere by emitting carbon dioxide, those changes will endure on the timescale of many human lives.