by Dr Roger Pielke, Sr.
With the McShane and Wyler paper examining and questioning the method, this look at the proxy data and its problems seems like a relevant issue to review.
Comment On Tree Ring Proxy Data and Thermometer Type Surface Temperature Anomalies And Trends
There was an interesting conclusion in a New York Times article on the relationship between tree ring proxy temperature trend analyses and thermometer type measures of temperature anomalies and trends. The article is
British Panel Clears Scientists by Justin Gillis published on July 7, 2010
The relevant text is on page 2 it is written
“But they were dogged by a problem: Since around 1960, for mysterious reasons, trees have stopped responding to temperature increases in the same way they apparently did in previous centuries. If plotted on a chart, tree rings from 1960 forward appear to show declining temperatures, something that scientists know from thermometer readings is not accurate.”
There are, however, problems with this conclusion. Since the thermometers are not coincident in location with the tree ring data (in the same local area), it would not be surprising that they are different. Indeed, this is yet another example that implies unresolved biases and uncertainties in the surface temperature thermometer type data as we discussed in several of our papers (see and see), as the thermometers are measuring elsewhere then where the proxy tree data is obtained. This obvious issue has been ignored in the assessment of this so-called divergence between the two methods to evaluate temperature anomalies and trends.
It is possible, of course, that the trees are responding differently due to the biogeochemical effect of added carbon dioxide and/or nitrogen deposition. Nonetheless, to accept the thermometer record as the more robust measurement of spatial representative temperatures is premature.
I have discussed this issue further in the posts
Comments On The Tree Ring Proxy and Thermometer Surface Temperature Trend Data
December 2007 Session ‘The “Divergence Problem’ In Northern Forests
The solution to the divergence problem is simple. Just rename it, call it the “dendrothermal inversion anomaly” or something. Then the problem is gone. This is fully in accord with the standards of climate science.
And for the rest of us in NE Oregon, strong radiational cooling could put our gardens at risk as well. But then pressure systems that bring such cooling will NOT be tied into the global average because just the data is all that matters, not the weather pattern variations responsible for the data. Trouble is, day time temps can mask what is really a cooling trend due to the clear sky condition that brings day time heat during cooling trends. Eventually the lag will catch up and La Nina will cool even day time temps.
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT SUN AUG 22 2010
ORZ041>044-049-050-501>506-WAZ024-026>030-501-502-231230-
EASTERN COLUMBIA RIVER GORGE OF OREGON-NORTH CENTRAL OREGON-
CENTRAL OREGON-LOWER COLUMBIA BASIN OF OREGON-GRANDE RONDE VALLEY-
WALLOWA COUNTY-FOOTHILLS OF THE BLUE MOUNTAINS OF OREGON-
NORTHERN BLUE MOUNTAINS OF OREGON-
SOUTHERN BLUE MOUNTAINS OF OREGON-
NORTHERN WHEELER AND SOUTHERN GILLIAM COUNTIES-JOHN DAY BASIN-
OCHOCO-JOHN DAY HIGHLANDS-
EASTERN COLUMBIA RIVER GORGE OF WASHINGTON-KITTITAS VALLEY-
YAKIMA VALLEY-LOWER COLUMBIA BASIN OF WASHINGTON-
FOOTHILLS OF THE BLUE MOUNTAINS OF WASHINGTON-
NORTHWEST BLUE MOUNTAINS OF WASHINGTON-
EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON-
EAST SLOPES OF THE SOUTHERN CASCADES OF WASHINGTON-
525 AM PDT SUN AUG 22 2010
THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL AND NORTHEAST OREGON
AS WELL AS SOUTH CENTRAL AND SOUTHEAST WASHINGTON.
.DAY ONE…TODAY AND TONIGHT
THUNDERSTORMS
GRANDE RONDE VALLEY, WALLOWA COUNTY, SOUTHERN BLUE MOUNTAINS
OF OREGON, OCHOCO-JOHN DAY HIGHLANDS
AN UPPER TROUGH WILL MOVE ACROSS THE FORECAST AREA TODAY WITH SOME
LEFT OVER INSTABILITY AND MOISTURE ALONG THE EASTERN AND SOUTHEAST
BORDER OF THE FORECAST AREA THIS AFTERNOON. AS A RESULT THERE IS A
SLIGHT CHANCE OF THUNDERSTORMS ALONG THAT BORDER THIS AFTERNOON AND
EARLY EVENING. ELSEWHERE BREEZY TO WINDY CONDITIONS WITH COOLER
TEMPERATURES ARE EXPECTED. THE WINDS WILL DIMINISH TONIGHT WITH VERY
STRONG RADIATIONAL COOLING WITH POSSIBLY A FEW RECORD LOW
TEMPERATURES OVERNIGHT.
.DAYS TWO THROUGH SEVEN…MONDAY THROUGH SATURDAY
THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.
HIGH PRESSURE WILL RETURN TO THE AREA WITH A WARMING AND DRYING
TREND THAT WILL CONTINUE THROUGH WEDNESDAY. ANOTHER PACIFIC WEATHER
SYSTEM WILL THEN MOVE INTO THE REGION BEGINNING THURSDAY WITH
ANOTHER COOLING TREND AND INCREASING WINDS ACROSS THE AREA FOR THE
LATTER PART OF THE COMING WEEK.
.SPOTTER INFORMATION STATEMENT…
SPOTTER ACTIVATION MAY BE REQUIRED.
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
GRAPHICAL FORECASTS OF WEATHER HAZARDS OUT TO SEVEN DAYS
ARE DISPLAYED ON THE WORLD WIDE WEB AT:
http://WWW.WRH.NOAA.GOV/PDT/CURRENTHAZARDS/HWO.HTML
ALL LETTERS IN THE ABOVE URL ARE LOWER CASE.
$$
Maybe tree rings are a poor thermometer
OR
On the flip side….maybe the earth where the trees were located was actually cooling!
From Mann’s view, this is not politically correct, but it is a possibility along with the “trees are poor thermometers” explanation.
Yes, dubious conclusions based on slim pickings. In summer months, in the forested NW, we leave the city, drive into the rural roads through the forests and see the temperature immediately drop 5 to even 12 degrees from what it is as we drove by the airport (where the official temp is recorded).
Trees, along with other botanicals, are chemistry driven; affected by temperature, nutrition, water,CO2 concentration, etc. To discard tree rings based on a mismatch from 1960 forward is silly. Look at the 1000 year old trees in old growth areas on the west coast. Easy to line up the periods of favorable climate to trees, but do they indicated just temperature? Consider that temperature has a significant impact on growth; slow in winter, fast in spring and early summer.
I do not take much heart in ground based thermometer readings parked in cities and airports. The highs and lows could exist for only a moment as the top of the hour temp is recorded. Consider frost forming close to the ground when the ambient temperatures are well above freezing. That alone is a hint that using data from a common micro climate is bad science. An inclusion of broad sources of micro climate samples would seem to improve the science of global climate, rather than the exclusive approach of current sampling.
In conclusion, the more data from a variety of sources, the better the science. How about that?
Could you please put a byline at the top of the post (or more precisely, where Dr. Pielke’s commentary starts)? Just to make the author perfectly clear.
Thanks.
[byline added per request. ~dbs]
Occam’s Razor, when applied to:
The simpler suggestion is that the way they are interpreting proxy data from trees is flawed, and/or that the homologous, “adjusted” surface temperature data as taken from thermometers is corrupted by their own confirmation bias.
It is most unlikely, or indeed inconceivable, that trees have started responding to temperature differently since 1960 than they have for billions of years previously.
“But they were dogged by a problem: Since around 1960, for mysterious reasons, trees have stopped responding to temperature increases in the same way they apparently did in previous centuries.”
Isn’t that the litmus test for proxies? How well they match the present?
Then trees are worthless.
Not because their might not be some signal there, but because we don’t know how to find it, read it, and don’t have a clue what it means.
Making it completely worthless……
While we are at it, explaining how tree growth correlates with temperature (bogus), perhaps we can have some “nuclear expert” explain the O18/O16 ratio as a proxy for global temperature.
Hum, the ONLY thing I know that changes that is the number of thunderstorms in tropical costal areas. (They enrich the O18, alledgedly by “fractional distillation”. I think the field effects and accelerator nature of lightning might be more likely the reason..) How and why these would correlate with global temperature ELUDES me completely.
Max (30 years working in nuclear power/technology..)
“But they were dogged by a problem: Since around 1960, for mysterious reasons, trees have stopped responding to temperature increases in the same way they apparently did in previous centuries. If plotted on a chart, tree rings from 1960 forward appear to show declining temperatures, something that scientists know from thermometer readings is not accurate.”
This is not a problem. You simply use Mike’s Nature trick to hide the decline. Prroblem solved.
Arno Arrak says:
August 22, 2010 at 8:33 am
“………Apparently these people believed that if you don’t like some of the data you collected you can throw it out and substitute other data that you do like. That was the trick to “hide the decline.” I have news for you guys: if you are a scientist you are not allowed to do this.”
Yeh, well, only if you’re a run of the mill scientist. That’s because run of the mill scientists don’t have the inherent insights to climate data like climatologists do. For evidence, I present the arguments against the M&W paper. Those guys are just statisticians and while they may be good with general numbers, there’s no way they can know all of the nuances of the magical climatological numbers. So, they’re wrong, just like the other statisticians (M&M) that take issue with the way climatologist handle their numbers.
From the ‘Climategate’ emails …. an email from John Daly says it all really.
Dear Chick & all
> the first is Keith Briffa’s rather comprehensive treatment of getting
> climate variations from tree rings: Annual climate variability in
> the Holocene: “interpreting the message of ancient trees”, Quaternary
> Science Reviews, 19 (2000) 87-105. It should deal with many of the
> questions people raise about using them to determine temperatures.
Take this from first principles.
A tree only grows on land. That excludes 70% of the earth covered by
water. A tree does no grow on ice. A tree does not grow in a desert. A
tree does not grow on grassland-savannahs. A tree does not grow in
alpine areas. A tree does not grow in the tundra
We are left with perhaps 15% of the planet upon which forests
grow/grew. That does not make any studies from tree rings global, or
even hemispheric.
The width and density of tree rings is dependent upon the following
variables which cannot be reliably separated from each other.
sunlight – if the sun varies, the ring will vary. But not at night of
course.
cloudiness – more clouds, less sun, less ring.
pests/disease – a caterpillar or locust plague will reduce
photosynthesis
access to sunlight – competition within a forest can disadvantage or
advantage some trees.
moisture/rainfall – a key variable. Trees do not prosper in a drought
even if there’s a heat wave.
snow packing in spring around the base of the trees retards growth
temperature – finally!
The tree ring is a composite of all these variables, not merely of
temperature. Therefore on the 15% of the planet covered by trees, their
rings do not and cannot accurately record temperature in isolation from
the other environmental variables.
In my article on Greening Earth Society on the Hockey Stick, I point to
other evidence which contradicts Mann’s theory. The Idso’s have produced
more of that evidence, and a new article on Greening Earth has
`unearthed’ even more.
Mann’s theory simply does not stack up. But that was not the key issue.
Anyone can put up a dud theory from time to time. What is at issue is
the uncritical zeal with which the industry siezed on the theory before
its scientific value had been properly tested. In one go, they tossed
aside dozens of studies which confirmed the existence of the MWE and LIA
as global events, and all on the basis of tree rings – a proxy which has
all the deficiencies I have stated above.
The worst thing I can say about any paper such as his is that it is `bad
science’. Legal restraint prevents me going further. But in his case,
only those restraints prevent me going *much* further.
Cheers
John Daly
I planted an Ash tree for a friend yesterday. Her Maple tree died, as most do in this part of the world. She was convinced it is due to global warming.
The guy at the nursery who sold us the tree says that Maple trees have always done poorly here, and that it is not a wise choice to plant them.
People attribute everything to CO2, because they have been brainwashed to do so.
Wow! I sense a really great cartoon here!
Imagine: Dr. Mann is standing in the middle of a forest, jumping up and down like two-year-old having a temper tantrum, shaking his fists at the trees and wailing “You’re not cooperating!!”
And of course the trees will have their hands (branches” on the hips (trunk), or crossed like crossed arms, and are giving him a roll-eyed look.
Oh hey, and here’s another suggestion: One of the trees —facing away from him— has a branch (hand) down and extended in his direction, and with the caption “Talk to branch (hand)!”
:o)
Other than that, whenever a scientist is heard —or said— to remark that a natural process ‘isn’t cooperating’ with him, that’s tantamount not getting his way with matters.
And isn’t that the essence of the matter, what with UHCN and GISS knocking off stations which don’t render up data with which they would agree?
Did it occur to anyone that you have to find a live tree that is hundreds of years old, and any evidence of climate change would be in dead trees.
for trees to be used as a proxy there needs to be some calibration done. Thats is take tree tring data and temperature data for the same timeframe and correlate tree ring to temperature …
Then you get a factor that allows you to equate a certain size of tree ring to a temperature …
It appears that the tree ring fools did some calibration from about 1900-1960 and then froze their calibration process.
If they continued to use the temps from the ’60’s forwasrd then their “historical” temperatures would have had to change and they like their historical temps just the way they are … all cooked up and fraudulent …
lets say that ring size 10 = 14 degrees based on their original calibration … from the ’60’s forward they are seeing tree rings of 8=14 degrees … (old factor would have said temp was 12 degrees) …
If they use the new temperature data to improve their proxy calculation then the old historic temperatures would rise alot … so much so that they would look silly … thus they must throw out the data …
foley hund says:
August 22, 2010 at 9:49 am
[–snip for brevity–]
In conclusion, the more data from a variety of sources, the better the science. How about that?
There is a problem with using a wide variety of indicators: Each are subject to a broad range of differing effects.
The very nice thing about instrument data is that they afford a high degree of repeatability. That is, you may use a particular thermometer to measure temperature in many different locations, and it will perform that task admirably well provided the siting is the same in all locations.
If you are intent upon using flora as a means of measurement, then of necessity you must resort to measuring all manner of other things in that particular local environment in order to accurately assess what else is affecting the flora.
As has been pointed out priorly in other topics, tree growth is affected by precipitation, sunlight, the character of the earth in which they grow, their surroundings, insect predation, disease, etc.
Since all of those things are affected by the externalities of what causes weather to happen to begin with, then it arises that measuring those things and quantifying them is all the more the better way to understand what happens down the line.
In defense of tree rings, they’ve kept a great record of temperatures from the 1850’s to the 1990’s when pulped into paper sheets and used to record thermometer readings.
Heh heh. It’s funny ’cause it’s true.
“Since around 1960, for mysterious reasons, trees have stopped responding to temperature increases in the same way they apparently did in previous centuries”.
————————————————————————————–
Anyone who finds this statement credible has left science (and reality) behind and entered wonderland…….
Its worse than we thought….
DFM
Reading the various comments Mr. Mann would probably smile , because in reality next to nobody is asking Mr. Mann to start verifying his own theories and in a way that the particulars can be verified by the whole scientific community . Mr. Mann as far as i am aware has always used funds of the community to signal his crazy prophesies . The best thing which could happen to him is to be given the opportunity to prove himself with contemporary data visible and fully identifyable for others .
Since he is working with funds from our society , our society is entitled to an open verification process by Mr. Mann himself . If he is really that good , he should receive the opportunity to whitewash himself and if he refuses than he should no longer be given any grants .
899 says:
“There is a problem with using a wide variety of indicators: Each are subject to a broad range of differing effects.”
Exactly why we use a variety. Else we put one only indicator at a location of whose choosing?
How else do we provide for the climate millions of years in the past? Ice core has limits, rock/geological has limits, trees have limits, ocean sediments, as well as all other measures to date. When they do not agree we investigate a hypothesis of reason.
I have to stay with more sampling is better. I enjoy my traveling thermometer; it says a lot about localized temperatures and why stationary instruments fixed at micro climates are in fact the obvious reason the tree rings do not jive with instrument data. Right? Wrong?
Hi all. Please search for “D’Arrigo” and read her summary papers on “the divergence problem”. The presentation above fails to mention that it affects a small percentage of far northern tree samples only. Trees closer to the equator do not exhibit this behaviour. Prior to ~1970 the northern and southern trees are highly correlated and their match to the instrumental record prior to 1970 is strong. Many possible causes of divergence for the individual stands affected have been postulated with no definitive answer. Note that proxy reconconstructions of past temperature follow a similar patter whether or not tree ring data are included.
Practice skepticism. Go to the source to see if this commentary is a fair reflection of the state of play.
Very valid criticism.
Uniformitarianism dictates that what happened in the past are the same processes and mechanisms that occur in the present, that we cannot assume different processes in the past.
If we prove that such differences existed, then uniformitarianism is shot in the foot. It is also shot in the head.
So, in them claiming something different for the period when instruments overlap with tree rings, they ARE saying, “Well, yeah, but you see, uniformitarianism doesn’t really apply unless we agree to LET it apply.”
So, not only do they cherry pick their data, they cherry pick the underlying scientific principles.
The rest of science should be all over this like flies on cow turds.
Oh? They won’t do that? Then someone else has to. . . . Enter Steve M and Anthony W…
————————————————————————————-
Paleontology-
We can date the relative age of certain index fossils based on the ages of the rocks that contain them based on their relative location in the geologic column.
We can date the relative age of certain rocks in the geologic column based on the ages of the index fossils they contain.
While this is not the only way in which the ages are assigned to either rocks or fossils, and these other methods are more or less in agreement (there are notable exceptions in recent recorded history) there is more or less a consensus that the geologic column (as currently understood) to be a fairly reliable proxy to use in dating either fossils or rocks. It does not matter that at no one place on the earth do significant portions of this column exist or that at other locations the order of rock layers are out of sequence or even inverted. Such divergences are dealt with by many (sometimes complicated) theories about never observed events in the name of preserving the integrity of the idea of a geologic column as a proxy for recorded ancient history.
I am not arguing the truth or falsity of the idea of a geologic column just pointing out a few similarities between it and the idea of a “treemometer”.
I always thought that plants responded to ground temp not air temp.
Maybe we need to bury the thermometers!!