Ouroboros_Rex wrote:
"Peter Franks" wrote in message
...
Roger Coppock wrote:
Expert: Warming Climate Fuels Mega-Fires
Scott Pelley Reports From The American West's Fire Lines On The Rising
Number Of Mega-Fires
Oct 21, 2007 CBS News

[ . . . ]

The severity of the burning and size of the fires caught the eye of
Tom Swetnam, one of the world's leading fire ecologists. He wanted to
know what's touched off this annual inferno and whether it's truly a
historic change.

At the University of Arizona, Swetnam keeps a remarkable woodpile,
comprised of the largest collection of tree rings in the world. His
rings go back 9,000 years, and each one of those rings captures one
year of climate history.

Swetnam found recent decades have been the hottest in 1,000 years...
Were tree rings used to determine the temperature for the past 1,000
years? If so, how is that done?

http://www.google.com/search?hl=en&q...&btnG =Search

That doesn't answer my question.

Let me rephrase it so that there is less of a chance for confusion:

How did "Swetnam [find that] recent decades have been the hottest in
1,000 years"?