curryja wrote “Note, the article says 90% probability that CO2 increase is above natural variability. This is very different from absolute certainty that 100% of the increase is caused by humans”
I’m sorry Prof. Curry, you have indeed misunderstood the article. The article does not say there is “a 90% probability that the CO2 increase is above natural variability”, it says that there is a (small) increasing trend in the airborne fraction that has a 90% probability of being above natural variability. The airborne fraction is not the CO2 increase itself, it is the proportion of anthropogenic emissions that remain in the atmosphere. I am very surprised that you appear not to grasp this fundamental distinction, and rather disappointed by your dismissive reaction (“No it doesn’t, read it again.”) to those who have pointed out your error.
Rather than asking for people who might write a guest post on dynamical models of atmospheric carbon, why not ask an expert, such as Prof. Le Quere, or Colin Prentice or Ken Caldeira or David Archer or Josep Canadell?
BTW, you can find the mass balance argument in this paper, co-authored by Prof. Le Quere:
http://www.globalcarbonproject.org/global/pdf/Raupach_et%20al.%202008.Anthrop%20&%20bioph%20contributions%20to%20atmCO2.Biogeosciences.pdf
Note Figure 1d the green line is the net flux from the natural environment into the atmosphere, inferred from the observed atmospheric growth rate and estimated anthropogenic emissions. This flux is clearly negative, indicating the natural environment is a net sink and the net sink is becoming stronger as time goes on. That shows the rate is 100% anthropogenic as nature is OPPOSING the increase.
Now, if you compare anthropogenic emissions and the growth rate, you can see that one is an almost constant multiple of the other. That is approximately the airborne fraction. A change in the airborne fraction is not a change in the growth rate, it is essentially the rate of change in the growth rate, and you can see that this has actually changed very little over the last 50 years. THAT is the change that Prof. Le Quere is talking about in her paper.
BTW, Prof. Prentice also mentions the mass balance argument in his rebuttal of Prof. Salby’s hypothesis:
“1. The rate of accumulation of CO2 in the atmosphere is
less than the rate of emission from fossil fuel burning. Therefore, the ocean and/or land are sinks for CO2″
.
http://climatefutures.mq.edu.au/files/file/How%20we%20know%20the%20recent%20rise%20in%20atmospheric%20CO2%20is%20anthropogenic.pdf
I suspect you will have difficulty in finding a paper that explicitly states the relative contributions of man and nature to the rise in atmospheric CO2 because it is obvious that it is anthropogenic emissions that are causing it. Research papers tend not to state things that are that well understood by the research community.