These are not rhetorical questions, but a sincere attempt to understand your explanation for observed phenomena.

Dave

This region of paleoclimate has a significant problem called the Faint sun paradox.

This is not only in the change in GHG /luminosity as evolution tells another story.So one cannot use the former explanation without constructing a new evolutionary theory.Hence the paradox.

eg Pavlov 2001

Organic haze in Earth’s early atmosphere: Source of low-13C Late Archean kerogens?
Alexander A. Pavlov*,1, James F. Kasting*,1, Jennifer L. Eigenbrode*,1 and Katherine H. Freeman*,1

1 Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA

High concentrations of greenhouse gases would have been required to offset low solar luminosity early in Earth’s history. Enhanced CO2 levels are probably at least part of the solution, but CH4 may have played a significant role as well, particularly during the Late Archean era, 2.5–3.0 Ga, when methanogenic bacteria were almost certainly present. Indeed, biological CH4 production should have led to CO2 drawdown by way of a negative feedback loop involving the carbonate-silicate geochemical cycle. We suggest here that the atmospheric CH4/CO2 ratio approached the value of ~1 needed to trigger formation of Titan-like organic haze. This haze was strongly depleted in 13C relative to 12C and was produced at a rate comparable to the modern rate of organic carbon burial in marine sediments. Therefore, it could provide a novel explanation for the presence of extremely low-13C kerogens in Late Archean sediments.

http://geology.geoscienceworld.org/cgi/content/abstract/29/11/1003

Titan answers some open problems

http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=36370

I guess David will have to find a different source for his equatorial electrical currents then. You’d think the earth might generate quite a lot of it’s own juice though, with it having a spinning iron core and all that electrolyte in the oceans.

same range here:
Nature 425, 279-282 (18 September 2003) | doi:10.1038/nature01902;
High CO2 levels in the Proterozoic atmosphere estimated from analyses of individual microfossils
Alan J. Kaufman & Shuhai Xiao

Solar luminosity on the early Earth was significantly lower than today. Therefore, solar luminosity models suggest that, in the atmosphere of the early Earth, the concentration of greenhouse gases such as carbon dioxide and methane must have been much higher1, 2. However, empirical estimates of Proterozoic levels of atmospheric carbon dioxide concentrations have not hitherto been available. Here we present ion microprobe analyses of the carbon isotopes in individual organic-walled microfossils extracted from a Proterozoic ( 1.4-gigayear-old) shale in North China. Calculated magnitudes of the carbon isotope fractionation in these large, morphologically complex microfossils suggest elevated levels of carbon dioxide in the ancient atmosphere—between 10 and 200 times the present atmospheric level. Our results indicate that carbon dioxide was an important greenhouse gas during periods of lower solar luminosity, probably dominating over methane after the atmosphere and hydrosphere became pervasively oxygenated between 2 and 2.2 gigayears ago.

Please do give some feedback to Volantis’ post above. I know David and he is a deep thinker.
Unfortunately the post is flawed in so many places that it pains me to go through them all. Just a very glaring one: the Sun is not positively charged [surplus of ions] and the Earth is not negatively charged [surplus of electrons]. The electric force is about1,000,000,000,000,000,000,000,000,000,000,000,000,000 stronger than gravity and the slightest imbalance would wreak havoc with the Earth’s orbit.

Please do give some feedback to Volantis’ post above. I know David and he is a deep thinker.

gary gulrud (13:31:57) :
Let’s see, we have a recurrance of global temps rising to 72 degrees F
Global temps were once 70C, and of course due to CO2.

I’m left wondering what evidence we have for co2 levels billions of years ago. Is it a theoretical value based on an assumption that the temperature of the earth was around the same as today’s?
There is a good body of evidence. One of the simpler one is that the Sun was 30% dimmer back then and we know we had liquid water, because there a sedimentary rocks from then. So we need a greenhouse effect to account for that.

Here is one account: http://www.sciencedaily.com/releases/2003/09/030918092804.htm

I’ll assume that my maths was right after all since you seem to have dropped the issue. :-)
I may have misunderstood you, as you started out with 20ppm and I thought you were talking about future levels up from there. If it was just to tell us how much 2^5 and 2^6 was, then everything looks fine.