The meeting between GWPF representatives and Royal Society nominated Scientists has been eagerly anticipated by those interested in the "Climate Wars"
You state that the propsed agenda is as follows:
1. The science of global warming, with special reference to (a) the climate sensitivity to carbon dioxide and (b) the extent of natural variability;
2. The conduct and professional standards of those involved in the relevant scientific inquiry and official advisory process.
I urge you to reconsider this agenda for the following reasons.
First Item #2 is likely to degenerate into useless argument and recrimination .It will merely produce inherently unprovable opinions which in any case cast no light on the underlying scientific questions involved.The topic is of obvious interest but should be treated in a different forum from a discussion of the science itself.
As to Item #1 - The question is framed within the context of the IPCC- Met office Establishment Science modelling approach to Climate Forecasting.This assumes that this approach is valid and that "climate sensitivity to carbon dioxide" is a meaningful notion.There is in fact no consistent empirical relationship over time between global temperature and CO2.We can assume that ,over the oceans , temperature drives CO2 content since colder waters dissolve more CO2 but eg on an annual basis as temperatures rise CO2 levels fall as plants grow and absorb CO2. If ,like the IPCC and the Met office you irrationally wish to assume for modelling purposes that CO2 is the main climate driver then it is possible to pick time frames to produce any relationship you want.For example the ice core data shows clearly that for the Holocene from the Climate Optimum to the Little Ice Age Co2 can be regarded as an Ice House Gas. In any event unless the extent of natural variability is known with some precision it is not possible to estimate the climate sensitivity to CO2 even if such a concept makes any sense.
But the situation is more basic than the obvious structural deficiences of the specific IPCC models . The modelling approach is simply inherently incapable of dealing with a system as complex as climate because it is not possible to define the initial parameters of the many variables or to structure the model with sufficient precision to iterate the multiple processes forward with any measurable accuracy.Even if the model was successful for some reasonable period of time you would not know whether it represented reality and could be used for prediction or simply was the sum of compensating errors.
The question that should be raised with the RS representatives is that of the basic uselessness of all the IPCC modelling and all the impact studies based on these models.
Clearly the better way of forecasting climate is to run power spectrum and wavelet analysis of the best temperature and all possible driver time series to look for correlations and quasi cyclic periodicities at various frequencies.When this is done reasonable projections can be made. These can be regarded as educated guesses based on the scientific judgement of the maker. If this does not seem scientific or rigorous enough then call them Bayesian inferences to impress the non scientist but they are the best we can do now.At this time the Milankovic cycles are well established as are a 60 year and less certainly a millenial solar cycle. Based on these cycles and the current solar data it is reasonable to infer that the earth entered a cooling trend in about 2003 which will likely last for another 20 years and possibly for several hundred years beyond that.It is also reasonable to conclude ,without even knowing the exact mechanisms involved ,that " solar activity" is the main driver and that the cosmic ray count and or the 10 Be flux is the most useful proxy for measuring this variable.For links to the data and papers on which these propositions are based see the relevant posts on http://climatesense-norpag.blogspot.com starting with "Climate Forecasting Basics for Britains Seven Alarmist Scientists and for UK Politicians."
Best Regards Norman Page.