Excellent conclusion – and little wonder – the GCM’s suffer from the same problems economic modelling has – attempting to model phenomena that cannot be intrinsically modelled. Economic modelling attempts to predict what individual humans will do in an aggregate sense. Impossible.

Yet economic modelling continues to be used by the Keynesians to guide policy despite the facts that it is gobbledygook. So I suspect the GCM’s will also be used to guide policy despite the facts you summarise above.

As Captain Binghampton of McHale’s Navy would have said “I could just scream!”

A current google of "Arctic ‘sea ice’ data" finds two pages filled mostly with references to the NSIDC data, with UIUC appearing only near the bottom of the second page. [snip]

but willis,
is this the same UKMO model that has the best statistical behaviour. If so what is the cause of the extreme climate sensitivity. How can the strong positive feedbacks of UKMO agree with the strong negative feedbacks you and doug find in the emperical cases?

Where do I find the details of cloud behaviour, aerosol sensitivity, solar sensitivity and greenhouse sensitivity for the UKMO “model”?

Is the UKMO model a model or a gridded set of observations?

http://www.grida.no/climate/ipcc_tar/wg1/056.htm

You have finally said what it was that you were on about re Coolwire 13. You show that there are two polar datasets, the UIUC dataset and the NSIDC dataset. One showed a record, and one didn’t. Fair enough, and I’m glad to hear of it, tho’ it doesn’t make much difference to my analysis. [snip] I had no idea that there were two datasets,[snip] . You yourself say you only discovered that there were two datasets through an "unlikely coincidence", [snip]
[snip]
w

I should also have mentioned the other co-authors of our submission to the UK Stern Review: Sir Ian Byatt, Chairman of the Water Industry Commission for Scotland, Senior Associate with Frontier Economics, Honorary Professor at Buckingham University and former Deputy Economic Adviser to HM Treasury; Lord Nigel Lawson, former British Chancellor of the Exchequer; Ross McKitrick, Associate Professor of Economics at Guelph University, Ontario; Julian Morris, Executive Director of the International Policy Network and Visiting Professor at the University of Buckingham; Sir Alan Peacock, Honorary Professor of Public Finance at Heriot-Watt University and a former Chief Economic Adviser to the UK Department of Trade and Industry; and Lord Skidelsky, Professor of Political Economy at the University of Warwick and author of the award-winning biography of John Maynard Keynes.

I did mention Colin Robinson, Emeritus Professor of Economics at the University of Surrey, but should also have noted that he is a recipient of the International Association for Energy Economics award for ‘Outstanding Contributions to the Profession of Energy Economics and its Literature.’ And I should also have included Professor William Nordhaus of Yale, who was the keynote speaker at the IPCC Expert Meeting on Emissions Scenarios in Washington, D.C. in January 2005, and Professor Peter Dixon of Monash University, Melbourne, whose research with Maureen Rimmer of that University was presented at an economic modellers’ conference at Lubeck, Germany in June 2005. The work of Dixon & Rimmer, as of McKibbin, Pearce and Stegman, was supported by the Australian Greenhouse Office.

For the sake of completeness, and with apologies to those who don’t care, I also record that I am a former Head of the Australian Bureau of Statistics and of the Australian Department of Finance, a former President of the International Association of Official Statistics, and a former Executive Director and Vice-President of the Academy of the Social Sciences in Australia. My review of the Eurostat OECD-PPP Programme was described in the OECD’s PPP methodological manual (June 2005) as “an important milestone in its history. Most significantly, it confirmed the usefulness of PPPs and fostered a better understanding of their respective responsibilities and roles between Eurostat, the OECD and participating countries.”

Finally, let me quote from a message that was widely circulated in 2001 by Dr. Jacob Ryten, former head of economic statistics at Statistics Canada and consultant to the United Nations Statistical Commission on the International Comparison Programme:

“Both Ian Castles and I [Jacob Ryten] were commissioned to look into the worldwide conditions of PPPs and to recommend what should be done about them if the estimation thereof had fallen into disrepair. In our two reports, which were written independently, we discussed the many improvements required to bolster the use and credibility of what we both rated an indispensable tool for inter-country economic comparisons. We also argued – persuasively, I thought at the time – that whatever blemishes could be attached to the latest PPP rates or to the time series of PPPs, they were of little consequence when compared to the distortions entailed by comparisons based on straight exchange rates…. If indeed there are very serious doubts about PPPs, the only course of action open is to abstain entirely from making comparisons involving GDPs per capita.”

It’s hard to bear that two US economists found that projections of GHG emissions weren’t much affected by whether PPP and MER measures don’t much affect projections of emissions, but I think I can live with it.