It’s the adjustments to the raw data - and almost always upwards - that produces so much of the 20th century warming. So how sound is the science behind those adjustments?

We’ve earlier marvelled at the amazing adjustments by which the IPCC created this warming in Northern Australia:

From these raw results:

Now climatologist Dr Richard Keen of the University of Colorada wonders how this warming in Alaska was produced by a supplier of IPCC data:

When Keen finds a warming in fact of just this:

Says Keen:

My averages show that the past three decades have shown no warming (since the PDO shift in 1977), and are in fact no warmer than the 1935-1944 decade.  This is very different from the IPCC which shows a substantial warming over the past three decades....

One can only guess what “corrections” were applied to the GHCN and IPCC data sets, but I can easily guess their magnitude – about 1 degree.  Curiously, the magnitude of the adjustments is about the same as the “global warming” signal of the past century.

I’d be interested if other readers can provide similar comparisons with other parts of the world.

UPDATE

Professor Sinclair Davidson says the Rudd Government is right - Tony Abbott is hundreds of billions out when he says the Government could cost us $400 billion if it caves into the pressure at Copenhagen. Trouble is, the true cost is even more.