Which facts are you querying? Pete's use of -40C in winter and 0C as the
average temps for the NP seems reasonable to me. The only other figures
he's used are your own.

I am not querying Pete's values. What I want to know is what his
source is, so that I can use a similar one without fear of being told
my source is unacceptable.

But -40C seems to me more typical of Siberia and Antarctica rather
than the Arctic where I would have thought the average was closer to
-20C.

In fact 20 C is the average of 0C and -40C quoted in Wikipedia for
winter temperatures. See:
http://en.wikipedia.org/wiki/Climate_of_the_Arctic

What I would suggest as the mistake Pete has made is to apply your 24C
Polar correction equally across Winter and Summer. Such a rise - or even a
much smaller one - would see most of the Arctic Ocean ice-free throughout
the year. This lack of ice in Winter could mean a rise of about 40C to
near 0c but Summer temperatures, to achieve the 24C annual rise could rise
to 8C.

My figures were very much "finger in the air." They were only
intended to show it was feasible for alligators to return to the
Arctic.
http://www.thecanadianencyclopedia.c...=A1ARTA0010389

One could analyse the polar amplification that has happened over the
last 100 years, but then as they say "Past performance is no guide to
the future."

The only projection I have for distribution of temperatures is over thirty
years old - I need to get a bit more up-to-date - and, for a 3C global
rise, has local rises of around 2C from the equator to near 40N and 10C
North of 80N. The UK latitude would be 3.5-4C.

Interesting, and it roughly bears out my crude figures of equatorial
warming equal to the global value, double the equatorial warming in
the UK, and double again in the Arctic.

Oh well I have dug out some facts after all, wasting a morning
preparing this post :-(. Never mind.

Cheers, Alastair.