The IPCC base their claims about how much warming is ‘in the pipeline’ on the rate that carbon dioxide is eventually removed from the atmosphere, the ‘e-folding time’. This is different to the time it takes for any emitted joe-average co2 molecule to be re-absorbed in the carbon cycle, and reflects the assumptions made about the way the carbon cycle operates.
The IPCC relies on the ‘Bern model, which was cooked up many years ago by Bert Bolin and other atmospheric scientists of the warmist persuasion. The Bern model makes assumptions which lead to a very long e-folding time of hundreds of years, a figure which has been disputed by several able researchers, and discussed here at the talkshop in previous posts.
Now talkshop co-blogger Tim Channon has made novel use of data which shows what has happened to the radioactive carbon 14 isotope carrying co2 levels since the atmospheric nuclear bomb tests of the early 1960’s. The results look like another hole below the waterline for the IPCC and the climate alarmists. – tb
Figures 1 and 2 are demonstrating both northern and southern hemisphere decay from a Dirac injection of a test signal. The consequent effect is very close to perfectly linear, proportionality between pressure and effect of pressure over more than an order of magnitude of data variation (hence linear law). This seems to destroy IPCC claim of a non-simple law. Deviation is <1%
In addition the effect is a simple low pass filter on all kinds of atmospheric carbon dioxide. A later article might cover this in detail.
Note: this article is cross posted from the authors blog, discussion is probably more appropriate on the Talkshop. Some of the content has been the subject of wide discussion around the ‘net but not so far as I know here. — Tim