Everything Dr. Rabett said about the Knorr paper, with the exception of how to spell Dr. Canadell's name, is altogether right and true and clear and proper. This is not my opinion so much as it is settled scientific consensus that there is a controversy. It is a closed question that there is an open question. To wit:
There is a very simple way to put it:
We know the amount of CO2 emitted by us per year (pretty well) Call it X.
We know the amount of this CO2 that stays in the atmosphere (the rest goes into the oceans and the biological bits of the land). That is, for reasonable purposes X/2 or 50%.
That means that 50% of the CO2 that we emitted each year remains in the atmosphere.
The question is whether the fraction is changing. Maybe only 48% is absorbed and 52% remains in the atmosphere.
Knorr says the fraction is not changing. Canadell says the fraction remaining in the atmosphere is increasing.
Canadell is really serious trouble. Knorr is only serious trouble.
That's all folks.
The only thing we can be sure of about the future is that it will be absolutely fantastic. So if what I say now seems to you to be very reasonable, then I have failed completely. Only if what I tell you appears absolutely unbelievable, have we any chance of visualizing the future as it really will happen.
- Arthur C. Clarke (h/t Brin)