It is easy to see on the CO2 charts, the seasonal fluctuation of ~3 ppm, is what the Earth's plant life can absorb. In a healthy biosphere there are plants that increase with more CO2 while others are less affected. At a normal max of 280ppm, nature has been unable to absorb the massive influx from fossil fuel burning especially after 1950. 120ppm up over the last 200 years.
We are many trillions of trees short of that needed.
In studying ecology it was a general rule that CO2 and O2 stayed in a balance. The thing missing was catastrophism. That comes from study of geology. In this case, green growth can not keep up with CO2 gain.
Human fossil fuel burning and gross overpopulation is a catastrophe for the biosphere. In progress!
