Re: [asa] Data doesn't support global warming

From: gordon brown <Gordon.Brown@Colorado.EDU>
Date: Tue Dec 15 2009 - 17:22:52 EST

On Mon, 14 Dec 2009, Glenn Morton wrote:

> GORDON BROWN ASKED: When was the last time that the Arctic Ocean was
> ice-free?
>
>  
>
> it very well may have been ice free 8-6 kyr ago during the Holocene climatic
> optimum. Sea levels were 2 meters higher, the world was 3 deg C hotter than
> at present, trees grew to the current coastline of the arctic a thousand km
> further north than they do today, there was no permafrost (trees don't live
> in permafrost)
>

It is not true that trees don't live in permafrost. Much of the boreal forest
is located on permafrost. The lower elevations of Alaska's interior are taiga,
not tundra. However the trees' roots cannot go deep because they encounter
permafrost. I recall once that a tour guide pointed out an area of forest which
he called a "drunken forest" in which the trees did not stand up straight due
to the permafrost underneath them. The existence of forest in these latitudes
is apparently determined by whether the average summer temperatures are high
enough.

Gordon Brown (ASA member)

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Received on Tue Dec 15 17:23:25 2009

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