[flogger]

Glad I could oblige. If you have any more questions feel free ....... unless of course ignorance is bliss,

Perhaps you should consider given that the isoptopic signature of fossil fuel Carbon can be tracked and that signature is largely missing suggesting the rise in CO 2 is primarily a natural phenomena. To go into more detail. I happen to have made a special effort to study this particular corner of the debate in depth and the answers dovetail into virtually all other facets of the debate as well, so please indulge me to address this point first

Firstly you should know that the mean half-life of atmospheric CO2 was already well-established decades before the start of the debate about climate change. Until 2009, there were 36 studies of the half-life of atmospheric CO2 conducted between 1957 and 1992. Two more studies were completed and published this year. The range of half-life periods obtained from the 36 studies were between 2 and 25 years, with a mean of 7.5, a median of 7.6, and an upper range average of about 10. Of these 36 values, 33 are 10 years or less. The simple average for the 36 studies is 5.6 years. Not even one of these studies showed a half-life anywhere close to the "50-200 years" of Houghton, et al 1991, which is unabashedly attributed to computer modeling, and on which the IPCC continues to rely for their tabulations.

We have to admit that whatever we observe about CO2 concentration in our present atmosphere, and then whatever hypothesis we form concerning CO2 concentration, must be consistent with the considerable weight of the well-established body of knowledge contained in the 36 studies . No one anywhere has suggested that any of these studies is deeply flawed or that the conclusions about the CO2 residence time is in error. The methodology of the studies is not in question, either.

The amount of cumulative anthropogenic releases is fairly well tabulated, and reliably believed to be about 250 billion metric tons totally, and about 8 billion metric tons annually, at present. Using these two pieces of the puzzle (releases and residence time expressed as half-life), we can reconstruct the atmosphere as it exists today within a mere few ppm of actual measurements. But the key point is that in order to successfully reconstruct the atmospheric CO2 content from cumulative emissions, we must use the ~5.6 year half life.

But what happens when we reconstruct the present atmosphere using the AGW orthodoxy's numbers for residence time, namely a "50-200 years" half life? When the IPCC does so, they find that the atmosphere contains only half of the expected CO2! The half life figure the IPCC uses must be wrong; ALL previous studies based on actual measurements conducted over a ~60 year period by diverse teams in different countries all came to the conclusion: that CO2 has a short residence time.

As an additional proof, we can measure the fraction of fossil fuel sourced CO2 which is contained in the present atmosphere. This is possible because carbon from ancient sources has a significantly different isotopic 'signature' than carbon from recent sources. Specifically, the signature for recent 'naturally sourced' carbon is agreed to be ~ -7 pdb. The isotopic fingerprint of ancient fossil carbon is agreed to be ~ -26 pdb. All the isotopic mass-balance studies done so far show a figure of ~ -7.5 to -7.8 pdb, which is close to the signature of pre-industrial carbon, with some slight shift toward the fossil signature of -26 pdb. Using simple calculations, the present atmosphere contains about 4% 'fossil-sourced' carbon using the reliable and well-accepted methods of testing.

Now the IPCC and all the believers in the AGW orthodoxy assert that anthropogenic releases are the cause of the observed CO2 rise. Because of (among other things) the isotopic signature, we can test this hypothesis. The IPCC specifically claims that 21% of the CO2 in the current atmosphere is due to anthropogenic releases, but NO study is offered in support of this claim. 21% corresponds to about 75ppm, which when subtracted from 380ppm gives us 305ppm, very close to the "pre-industrial baseline" figure, thus the 21% attribution amount to an "all or nearly all" attribution.

If we accept that "all or nearly all" of the observed CO2 rise is due to anthropogenic releases, and that CO2 has a long residence time as claimed by the IPCC (Houghton, et al, 1991), then it's a simple matter to calculate the expected isotopic signature of the carbon in the present atmosphere; we have all information needed to make this calculation. The expected mass-balance figure is ~-11pdb for the 21% attribution. The problem is, no mass-balance study yet can confirm that the mass-balance signature of the CO2 in our recent atmosphere is ANYWHERE CLOSE to -11pdb, but rather in the -7.5 to -7.8pdb range, very close to the signature of recent CO2 of around -7pdb.

Thus the isotopic mass-balance measurements CONSISTENTLY falsify the argument that "all or nearly all" of recent CO2 rise is due to anthropogenic releases. The idea that CO2 has a long residence time is only the result of computer modeling done in 1991, and contradicts ALL the measurement studies ever done. The implication of a ~5 year half life is that of the 750 billion metric tons total atmospheric CO2, between 135 and 150 billion metric tons of CO2 is 'fluxed' from the atmosphere annually, totally swamping out the puny 8 billion metric tons of annual human emissions.

The fact that the IPCC's 'expected' isotopic signature is missing from all measurements does not support the conclusion that CO2 accumulates in the atmosphere, or that anthropogenic emissions have significantly contributed to recent CO2 increases. The fact that the IPCC's tabulations have a 50% error of missing CO2 is further confirmation that this hypothesis is in error, and the explanation of the carbon cycle proffered as a corollary to the AGW hypothesis is also wrong.

The postulate that the oceans are sinking the 'missing' CO2 cannot be squared against the well-treaded science of Henry's law; the oceans are simply too warm to have absorbed such an enormous amount of carbon (on the order of 12,500 billion metric tons or ~50X cumulative anthropogenic emissions, or 400 billion metric tons annually) nor can it be plausibly asserted that this amount of CO2 is being released or has ever been released, or could ever be released as it exceed all the carbon embodied in all the world's fossil fuel reserves.

These glaring contradictions are ALL the result of trying to assert that CO2 accumulates in the atmosphere when we already knew from reliable direct measurements that this is impossible. Its these glaring misrepresentations of science which the IPCC presents in its summary to policymakers that have made a total mockery of the whole AGW premise in my view and that politics is now in the driving seat.