“…we conclude that changes in plant decomposition and [soil respiration] due to global temperatures primarily control global CO2 cycles.”  − Nishioka, 2026

CO2 changes have been observed to lag temperature changes (warming) via soil respiration since 1979 (r = 0.74). The consistent uni-directionality is T→CO2.

Anthropogenic CO2 accounts for 4% of the carbon cycle and CO2 just 4% of greenhouse gases (i.e., 96% water vapor derivation).

Thus, “an increase in anthropogenic CO2 since the [1700s] has contributed too little to affecting the global CO2 concentration.”

Image Source: Nishioka, 2026