Residence Time vs. Adjustment Time of Carbon Dioxide in the Atmosphere

Entropy (Basel). 2023 Feb 20;25(2):384. doi: 10.3390/e25020384.


We study the concepts of residence time vs. adjustment time time for carbon dioxide in the atmosphere. The system is analyzed with a two-box first-order model. Using this model, we reach three important conclusions: (1) The adjustment time is never larger than the residence time and can, thus, not be longer than about 5 years. (2) The idea of the atmosphere being stable at 280 ppm in pre-industrial times is untenable. (3) Nearly 90% of all anthropogenic carbon dioxide has already been removed from the atmosphere.

Keywords: adjustment time; anthropogenic carbon dioxide; atmosphere kinetics; residence time.

Grants and funding

This research was funded by the FCT—Fundação para a Ciência e a Tecnologia—Portugal, research center “CEOT” (UID 00631).