Thanks, that's interesting but not relevant to my question.
I guess I misunderstood what the question was about. I could have sworn the issue was about how fast CO2 concentrations were increasing as a consequence of anthropogenic additions to the atmosphere and how that may relate to projected changes in climate.
The data clearly demonstrates that the trend in CO2 growth from anthropogenic sources is toward a linear increase as oppose to exponential as claimed.
As far as known sources and sinks are concerned the following table represents what little has been estimated:
Atmospheric content of CO2 750 billion tonnes (Gt) [Schimel et al. 1995], @359 ppm concentration [IPCC 1995]
Atmospheric CO2 Flux billion tonnes(Gt) per year, [Schimel et al., 1995] Ocean Surface Land Anthropogenic Sources 90 60 7.1 Sinks 92 61.4 Unk
Unfortunately one of the big problems with the above is that recent studies are showing significant returns of CO2 back into the atmosphere above and beyond the above older studies in the form of microbial decay products of plant sequestered CO2 out of peat bogs and old growth plant detritus putting high levels of organic CO2 back into the atmosphere along with organic fossil fuel emissions.
http://www.silsoe.cranfield.ac.uk/nsri/research/carbonloss.htm
Bellamy P.H., Loveland P.J., Bradley R.I., Lark R.M. & Kirk G.J.D. (2005) Carbon losses from all soils across England and Wales 1978–2003. Nature, 437, 245-248.
Summary of the findings
We have found losses of carbon from soils across England and Wales that are on an enormous scale. Given the current debate on soil carbon stocks in relation to climate change and the potential for carbon sequestration in soils, these results are of huge international importance. They are the first of their kind at a regional scale anywhere in the world.
A separate and earlier study involving peat bogs appears to potentially have even greater impact arising from previously unsuspected sources of organic carbon release into the atmosphere:
http://www.newscientist.com/article.ns?id=dn6124
Peat bogs harbour carbon time bomb
- 18:22 07 July 2004
- NewScientist.com news service
- Fred Pearce
The world’s peat bogs are haemorrhaging carbon dioxide into the atmosphere, accelerating global warming, warns a UK researcher.
And worse still, the process appears to be feeding off itself, as rising atmospheric levels of carbon dioxide are triggering further releases from the bogs.
Billions of tonnes of carbon could pour into the air from peat bogs in the coming decades, says Chris Freeman of the University of Wales at Bangor, UK. “The world’s peatland stores of carbon are emptying at an alarming rate,” he says. “It’s a vicious circle. The problem gets worse and worse, faster and faster.”
Peat bogs are a vast natural reservoir of organic carbon. By one estimate, the bogs of Europe, Siberia and North America hold the equivalent of 70 years of global industrial emissions. But concern is growing that such bogs are releasing ever more of their carbon into rivers in the form of dissolved organic carbon (DOC).
“There seems to be an increase of DOC in rivers of about 6 per cent a year at present,” says Fred Worrall of the University of Durham in the UK, who collates global data on DOC levels in rivers. Worrall suspects the rise in DOC began about 40 years ago.
*** SNIP ***
Recent data from the Centre for Ecology and Hydrology in Lancaster, UK shows a 90 per cent increase in DOC levels in Welsh mountain rivers since 1988.
“The rate of acceleration suggests that we have disturbed something critical that controls the stability of the carbon cycle in our planet,” Freeman says. “On these trends, by the middle of the century, DOC emissions from peat bogs and rivers could be as big a source of CO2 to the atmosphere as burning fossil fuels.”
Journal reference: Nature (vol 430 , p 195)
However, the real issue as I pointed out it what is means in regards to climate change. The bottom line is actually not very much, as the direct radiative effect on surface temperature of doubling CO2 concentration in the atmosphere is only about 0.2oC.
No, I was questioning whether human activity accounts for the recent considerable increase in atmospheric CO2. All I was looking for was data in tabular form so I could do the correlation myself. I've got human CO2 emissions since 1751 and I'm still looking for the CO2 concentrations that include that time range.
That information about the bogs is interesting.
Can you expond a bit on this geezer?