The inescapable fact is that individual molecules make up the sum that lead to the flow rates and half life Ferdinand is describing, so the individual molecules do relate to atmospheric concentration, in the short term I’m describing.

Not true, take for example a steady state planet where the pCO2 in the atmosphere is in exact balance with the ocean concentration the half life based on individual molecules will still be about 5 years whereas the rate of change in [CO2] would be zero!

Re: Lucy Skywalker (#50),

I apologize for not stating more precisely that there were no specific citations. Steve is correct that there are implied citations. In re-reading AR4, however, I don’t believe it resolves the issues that I have raised. Unfortunately, discussing that with particularity would make for a very lengthy comment, as Steve has correctly pointed out. In lieu thereof, I think for reference purposes and in order not to leave these issues hanging completely, I would make reference to http://www.climateaudit.org/?p=5416 for a very lengthy and very interesting discussion of some of the same issues that I raised.

Finally, I want to make clear that my focus was more on the idea that warming is a result of all the greenhouse gases acting in concert rather than some acting individually (such as CO2). This eventually leads to whether water vapor is a dependent variable (dependent on CO2 levels), an independent one or perhaps one that is only partially dependent (on CO2). My primary focus was not on feedback itself, although the two are inter-related.

I don’t really want to waste bandwidth on this but I suggest you look at section 7 here for a simple example of why the half life of an individual CO2 molecule is not related at all to the half life of atmospheric concentration. Your bucket analogy is far too simple. There are several flows in and out at very different rates and several other buckets that the flows are going between with each one a very different size.

DeWitt, I eliminated the seasonal cycle when I did that chart, mine is much like yours and shows an increase even with decreasing temps (the slope of the CO2 is net positive, so the derivative will be too). The point on that chart is that the reaction of CO2 rate to temperature is extremely fast, with almost zero lag, which supports my next point.

The slope I’m talking about is -25PPM/yr at the peak seasonal decline rate (different subject). I did some further analysis and come up with a time constant for life of a free CO2 molecule at 15.4 years here: http://wattsupwiththat.com/2009/06/17/bob-tisdale-on-ncdcs-usgrp-report/ … look for ” Michael D Smith (09:53:30)”. There are some other stats that fall out of that slope, but this is the MAX time constant. It could be (probably is) faster, but I’m only looking at the max -CO2 slope from the seasonal change. This determines the lower limit of the rate of exchange of CO2 in and out of sinks… The best analogy is probably a large bucket with a hole in the bottom, and a faucet flowing in. We cannot determine the flow rates of the two, but we can see that over the season, the bucket level rises and falls, and thus we can determine the net flow rate given the volume of the bucket, and the maximum slope of its rising and falling. An infinite variety of flow rates of the sources and sinks will satisfy the equations, as long as the slopes and levels are met. So the analysis I show is the minimum net flow rate out of the atmosphere that satisfies the -slope. The flow rates of the sources and sinks are likely (almost certainly) much higher, but balance. They can’t be determined from this simple data set.

50% in 100 years, as claimed, is preposterous given only this data set, as is 20% in 1000 years, for other reasons. Why they didn’t use a faster rate, when it has been discussed so much, presumably to death, is the point I was making. I thought that horse was dead.

Go read it. http://www.climatescience.gov/Library/sap/sap1-1/finalreport/sap1-1-final-all.pdf page 15 of 180 “For observations since the late 1950s, the start of the study period for this Report, the most recent versions of all available data sets show that both the surface and troposphere have warmed, while the stratosphere has cooled . These changes are in accord with our understanding of the effects of radiative forcing agents and with the results from model simulations”

Just because the seasonal cycle in the Mauna Loa CO2 data appears to correlate with temperature does not mean that temperature is the actual or sole driver. Considering that the fluctuation is likely related to terrestrial biologic activity, insolation could be the main driver. The high rate of draw down in the NH summer therefore only applies to summer like conditions, not the entire year. I can show from Antarctic ice core data that the lag in CO2 versus deltaD (a proxy for temperature) can be fairly well approximated by a linear transform of deltaD and a long time constant (~2000 years).

The question of the half life of an individual CO2 molecule in the atmosphere versus the half life of the concentration of atmospheric CO2 has been discussed to death elsewhere.