Tuesday, January 03, 2012

Why did trees allegedly stop functioning as thermometers last century? Let me count the explanations (three in this ClimateGate email alone)

Email 19

1. There are few tree-core series that extend beyond the early 1980s. This is because
many of the sites we're using were cored before the early 1980s. So most tree-ring records
just don't exist post 1980
. [Phil Jones]
If you look at the figure in the attached article in Science by Briffa and
Osborn, you will note that tree-ring temperature reconstructions are flat
from 1950 onward. I asked Mike Mann about this discrepancy at a meeting
recently, and he said he didn't have an explanation. It sounded like it is
an embarrassment to the tree ring community that their indicator does not
seem to be responding to the pronounced warming of the past 50 years. Ed
Cook of the Lamont Tree-Ring Lab tells me that there is some speculation
that stratospheric ozone depletion may have affected the trees
, in which
case the pre-1950 record is OK. But alternatively, he says it is possible
that the trees have exceeded the linear part of their temperature-sensitive
range, and they no longer are stimulated by temperature
. In this case
there is trouble for the paleo record. Kieth Briffa first documented this
late 20th century loss of response.

Personally, I think that the tree ring records should be able to reproduce
the instrumental record, as a first test of the validity of this proxy. To
me it casts doubt on the integrity of this proxy that it fails this test.

Jeff [Severinghaus]


Anonymous said...

The Climategate II emails exposes the probability that the temperature data and tree ring data used to generate the computer models "proving" AGW were in main manipulated to get the results the Climate Scientists wanted. Than, to add insult to injury, the raw data was discarded due to the fact said scientists knew if their data is used for the purpose of reproducing their results their shenanigans would be there for all to see. If not for all the corruption in government and their co-conspirators the media, all these AGW scaremongers would be in court being sued by now for their manipulation of the data. In reality, the real reason the AGW scaremongers are trying to force everyone to live a green lifestyle is not because they fear AGW (they know AGW is in large part based on faked data) it is because they hate the Western lifestyle and want us all to live like the North Koreans do, cold, starving and bowing to our dear leaders.

Anonymous said...

I'm no climate scientist, thank God, but it seems obvious to me that precipitation levels would have a much greater effect on tree growth than temperature.

Clearly that answer is far too obvious to be accurate ;o)