@farmerman,
I too have seen the geohistorical data on teperature and CO2 concentrations and noted the evident phase lag of CO2, particularly at the max/min points. Unfortunately I don't prtend to have an understanding of that either way.
The qualitative character of the carbon cycle is well enough known. The idea that in burning coal and petroleum we are reintroducing massive quantities of previously sequestered carbon into the cycle and that is likely a factor in the observed increase in the CO2 levels in the atmosphere is certainly plausible - even convincing. However, there are so many other factors influencing the carbon cycle, and more broadly, influencing both the thermal (IR) reflectivity of the atmosphere as it relates to earths radiation heat loss; as well as factors influencing the solar radiation impinging on the earth and the fractions reflected and absorbed, that I am far from convinced we have any ability to even rank the effects some of the key factors, much less accurately forecast the future.
Both High Seas and I have noted the paradox of numerical modelling in relation to this question. While it is increasingly possible to construct and use ever more sophisticated models of these (mathemadically non-linear and parabolic) processes and do so with with ever finer resolution, it is categorically impossible to know if the results have any meaning whatsoever over the time scales to which they are applied. Not only is the dynamic itself intrinsically unpredictable (though deterministic at least in principle) we don't have anything close to the data required to establish accurate initial conditions.
Much has been made of the recent release of the hacked e-mails from the British research lab. While I don't find any smoking gun in the rather superficial reporting I have seen so far, the results do affirm the effects of human nature at work in academia. Ambitious scientists, like others, seek advancement, notoriety, prominence and acclaim. Clearly connecting your work, however tenuously to the spectre of global warming makes it easier to get assess to current data and get yourself published. Equally clearly avowed skeptics and critics face an uphill climb in these same areas, Certainly this wouldn't be the first scientific orthodoxy that resisted contrary evidence, views and even those who express them.
The intensity of belief in AGW appears among many to go well beyond what they can possibly know or understand. That suggersts other, perhaps cultural and psychological factors may be at work. Europeans appear (to my casual observation) to be particularly affecrted by this. Perhaps that what you get in an increasingly childless, geriatric society. They confound their own decline with that of the planet.
