What happened to the Yamal trees - assuming
the record was accurate? The Siberian larches are sensitive
not only to temperature but also to moisture, nutrients,
CO2 and probably other factors, and microclimate issues,
perhaps shading from frost, wind, sunlight, neighbouring
trees dying, riverbanks shifting.
<<<Click on picture to see animation of
Yamal trees in their environment, and note highly local
variations. ^^^Click and zoom on map above to see
the prevalence of small ponds and changing river meanders
in a flat landscape in Yamal.
It looks like the trees are sensitive to something
(see below). But the correlation is not to local thermometer
temperature records. The sample of 12 trees used for calibration
with thermometers is ridiculously small; this outrage of
size of sample is compounded by the refusal to declare the
actual sample size and other relevant metadata for 9 years.
Now meet the Twelve Trees
with super-outlier YAD061 that tell us we are in a tailspin
of global warming. It's worth taking time to get to know them
I've used the graphs from
Id's work, with treering widths from each tree (black:
original data) and red: adjusted in the attempt to eliminate
bias due to age of tree). Steve
McIntyre said "I think that some information
can be gleaned from the nomenclature of the ID numbers...
There are 12 IDs consisting of a 3-letter prefix, a 2-digit
tree # and 1-digit core#. All 12 end in 1988 or later and
presumably come from the living tree samples. The nomenclature
of these core IDs url (POR01…POR11; YAD04…YAD12;
JAH14…JAH16 - excluding the last digit of the ID here
as it is a core #) suggests to me that there were at least
11 POR cores, 12 YAD cores and 16 JAH cores... YAD presumably
stands for Yadayakhodyyakha River; POR for Porzayakha River;
JAH for one of the unlabelled tributaries" (see
CRU archive Figure 3).
Straight away we see a bunch of extremely individual records,
plus a complete outlier YAD06. It is warming furiously as
the last century draws to a close. It seems to be going
nova. But its red-hot condition is not mirrored by YAD04
or YAD12, which both show recent cooling . In fact, none
of the others show a steady overall twentieth-century temperature
rise, though they all show some increase over the nineteenth
By far the strongest correlations among
these trees are for individual year spikes, somewhere around
1921, 1939, and 1965. Interesting, because Salehard does
record temperature spikes for the years 1924, 1943 and 1967;
1943 and 1967 are mirrored at Turuhansk - maybe temperatures
are being picked up. And this is further confirmed by the
five POR trees which all show the same warm spikes somewhere
around 1921, 1939 and 1965.
But these correlations still fail to support a longterm
temperature rise. Sure, the trees in POR all show a warmer
twentieth century. But if they correlate with thermometer
records, how to explain that the local thermometer record
does not correspond over a decadal time-scale, or give an
overall rise of 7ºC as Briffa's calibration shows?
At the very least, the treerings have been over-sensitively
calibrated, as well as given undue weighting for such a
The POR trees all show the early- to mid-nineteenth century
as cooler than the twentieth, but also cooler than the end
of the eighteenth. Only two of the five, POR03 and POR08,
show a warming trend right through the twentieth century
that looks like the global temperature pattern, and POR03
shows an altogether warmer eighteenth century. POR01 levels
off quite soon in the twentieth century; POR05 and POR11
actually decline towards the end.
POR all go right up from the 1921-1924 spike
on; but this is NOT reflected in the thermometer records
of either Turuhansk or Salehard, which reflect each other
strongly both annually and decadally.
The implication is that while treerings may well show temperature
fluctuations from year to year, these local spikes cannot
be safely calibrated to show longer, slower climate changes.
There are too many individual factors.
at Salehard, compared with Turuhansk, Yamal treerings, and GISS
Click on pictures to enlarge.
Salehard and Turuhansk thermometer records are very alike,
both short-term and longterm.
However they show no correlation with overall Yamal proxies
except for an upward trend.
||The scale of the upward trend of the proxies
is well in excess of both Salehard and Turuhansk individual
records, and the GISS collective record - even with GISS problems
of inappropriate adjustments for UHI and other station issues,
station loss, and Russian issues.
Conclusion: These Arctic
trees, stressed by being "on the edge", respond in
a highly individual way, and to many factors. The same hypersensitivity
that shows up year-to-year temperature differences, that enables
dendrochronology to work for dating events, makes the tree rings
into markers of local fluctuations but not good markers of even
decadal trends, let alone longterm climate trends. However,
the evidence of changing treelines might work. And in Yamal,
the treeline was further north in the Middle Ages.
Bouldin said at Climate Audit:
The ring width data from all the series, past
and present, are lined up by cambial age chronology (cambial
age = the relative age of each ring, from the pith or tree center).
The average of the ring widths for each ring, over all the trees
is then computed. This creates a "standard curve"
that reflects primarily the size-dependent part of the growth
response of the trees. This mean value series is then subtracted,
ring by ring, from the actual ring widths of each tree, thus
removing the diameter-related ring width component from each
tree, since the goal is to isolate the environmental signal.
The residuals from this detrending are then examined to see
how "complacent" they are, meaning how much they vary
from year to year. Those that vary the most strongly are the
most sensitive to the environment, and whether they were
responding to the same environmental factor is assessed by looking
at the spatial similarity of the variation pattern across trees,
across the area of interest.
But this last statement does not seem to be borne out by the
above highly individual, very different trees.
Page updated 13th October 2009