The Keeling curve is very well approximated with an exponential function with an offset $256$ [ppm] $$256+A\cdot e^{\alpha\cdot t}$$ where $A=1.095\cdot10^{-12}$ and $\alpha=0.0161$ ($t$ is in years b.c.)
In the graph below the raw data for the blue sawtooth curve is from NOAA, from the columns 'decimal date' and 'monthly average'.
From the very beginning 1958 the curve has an unbreaked tendency of emissions from fossil fuels and fossil materials and from the sees and the ground. Even the increased global warming the last 50 years must have affected the emissions but still the trend is untouched. How come? Which are the main sources of emissions and why is the trend so stable?
To limit the temperature raise below $1.5-2.0$ °C the pledges from the COP conferences must have an effect on the emissions that is unseen since 1958.