Despite being just another web site in the climate debate, Real Climate serves as a kind of shield for all opposition to the AGW theory. Since it is run by climate scientists and contributers to the IPCC reports it is therefore thought to have a special authority that goes beyond that of any other web site engaged in discussions of climate issues. In actuality Real Climate is a political tool that conducts carefully orchestrated debates on climate issues; and the outcome of those debates are forgone conclusions. Take any discussion or thread on Real Climate and look over it carefully. The pattern used by Real Climate authors and moderators is never changed. There are basically three kinds of articles posted on their site.
The first seeks to explain or highlight some new or reinforcing aspect of the AGW theory. For example, they will explain why the Arctic ice melt of 2007 is particularly important as supporting data for their theory, while the near record Antarctic ice extent of 2008 is not. Or they will explain why a thirty year temperature trend is important and a ten year one is not. The second kind of article that RC will frequently post is the kind where they attack some author or climate scientist that has published findings that are injurious or contradictory to their own conclusions. For example, they recently attacked Henrik Svensmark and his theory on the effects of cosmic radiation on the climate. The answers to RC's attacks on Svensmark were easy to find. But RC never allowed those answers to be posted. The third kind of article that RC posts are defenses of their friends when their friends have been caught in blatant acts of scientific malfeasance. Their recent defense of Briffa and his thin, inadequate, cherry picked data sets is one example of this. Their defense of Michael Mann and the errors in his proxy reconstruction is a classic. Their defense of the climate scientists involved in the CRU e-mail scandal is another example.
The kind of article that you will never see at RC is the kind that causes problems for the AGW theory. For example, the twentieth century divergence between tree ring data and surface instrument data is never given a thread - even though that divergence has been admitted to by members of the AGW cabal like Keith Briffa. The divergence between the climate models and the real climate history is also never discussed except in a defensive vein. For example, they always make the argument that the divergence is still within the error bands. This is the case even when all the models err on the same side of the real record and when the error is approaching the error limits for most of these models.
What RC seeks to do is to appear to derive a conclusion to these issues by giving them a fair hearing on their web site. A few commenters that are climate skeptics are always allowed to post a few comments that disagree with the RC position and with the AGW orthodoxy. But those comments from the skeptical side are very carefully filtered - not on issues of civility or relevance to the topic, but rather on the ability of the RC staff and the pro AGW/RC commenters to deal with the comments.
A few comments that can be considered as venting by the skeptics are allowed because they carry no weight on the actual debate. Some of the skeptics comments are known red meat for the pro AGW crowd at RC, and they are therefore allowed by the moderator because the moderator knows what will happen to them. A few of the more difficult posts from the skeptics are allowed and are dealt with by the moderator or article author by himself. The moderator will allow these for as long as he thinks that he has answers. If, in the course of a discussion with a skeptic the moderator runs out of answers for the skeptic's questions or objections, the moderator will simply censor the skeptics posts.
The whole purpose of the procedure is to give the illusion that the subject has been fairly and completely dealt with and that the pro AGW side has won - once again. From that point, any future arguments of similar issues by skeptics will simply be marked as, "discredited - see such and such a tread". The entire RC web site is full of victories that are won, not by science or logic, but rather by censorship. Of course the average reader of RC doesn't know this. He never sees the objections by skeptics that cannot be answered. All that he sees is the well orchestrated drama that was presented by Gavin Schmidt, his co-authors, and the regular crew of AGW supporters that frequent the site. The attempt by the scientists at the Hadley Climate Research Unit to illicitly control the debate about global warming by using their influence with publishers and the IPCC will come as no surprise to the thousands of skeptics that have had their legitimate questions censored at Real Climate.
A few examples of the kinds of posts that are censored by Real Climate in order to insure their own victory are captured in the postings below. I took some screen dumps of my submissions while they were in the moderation phase. Of course they were moderated out as I expected.
Tuesday, November 24, 2009
Tuesday, October 6, 2009
More Fraudulent Censorship at Real Climate.
Click on image to read.
As usual, Real Climate is showing a total lack of integrity. They are pushing the position that the temperature has continued to rise over the past decade with arguments that are borderline fraudulent. I tried to answer all of the points that they made, and of course I was censored. In the meantime the inmates of the site are doing victory dances because they see no opposition to their views.
Sunday, October 4, 2009
Real Climate attacks McIntyre
Saturday, October 3, 2009
Tree Ring Chronology Selection Problem
This article is an attempt to explain why tree ring temperature reconstructions have no value at all as they are currently done. I am not trying to make the point that they have no potential value; only the point that current methods of chronology selection destroy that value. To begin, I want to point out the method in question by using a quote from an Osborn/Briffa paper – 06 – SI.
Now here is a quote from Briffa responding to Steve McIntyre’s criticism of his Yamal chronology.
Now, one would think that this would be a good selection method if we wanted to use tree ring reconstructions to tell us 20th century temperature. But actually, it doesn’t even do that. The chronology simply mimics the surface temperature record; right or wrong.
But the real purpose of a reconstruction is to give us an idea of the relative temperatures of different periods of history. Especially those were we had no thermometers. And for that purpose, the selection method described by Osborn and Briffa absolutely destroys the value of the reconstruction.
It is clear from the descriptions of dendrochronologists themselves, as well as from what we know about tree growth, that trees do not all grow at the same rate, and the same tree grows at different rates throughout its life. One of the factors effecting its growth is temperature. But there are many others – sunlight, nutrient, water, CO2 availability etc. At any given point in time a tree may be able to respond to increases in temperature, or it may have it’s growth limited by a problem with the other factors. So, over the course of the life of a tree it may change it’s growth rate because it’s roots have reached a new source of nutrition; because the flow of water on the hillside where it is growing has slightly changed giving it more or less of the stuff; because a nearby tree has died giving it more sunlight; because a nearby tree has grown giving it less sunlight; because a nearby tree has died and it’s carcass is feeding the tree; because some bears have decided that it’s a good place to relieve themselves, etc. So let’s say that at any point in time a tree has a 60% chance of responding properly to temperature variation because it has the other resources that it needs. The number could be 20% or 80% - for purposes of this example it doesn’t matter.
So now, when we are in a period of increasing temperature, we select the series or the chronologies, as the case may be, that reflect that temperature rise. This means that 100%, or nearly 100% of the trees in the 20th century portion of the chronology are responding to temperature. If the number is much smaller, then only a fraction of the temperature rise will be reflected. But what happens to other historical periods within that chronology. The selection process did absolutely nothing to insure that those same trees were responding to temperature in say the Medieval Warming Period. So the likelihood that they are responding correctly to temperature tends to move towards our theoretical 60% average for those later periods. This means that by using Briffa and Osborn’s selection process, you are introducing a huge bias for having the 20th century show much more warming than the MWP. In fact, if the 20th century turns out to have anywhere close to the warming of the MWP, it will produce a chart where the 20th Century shows up as being much warmer than the MWP. And Al Gore can claim “unprecedented warming” for the 20th century.
I don’t know if Osborn’s and Briffa’s selection methods are unique to them. I rather doubt it. Most likely they are used by all of the dendrochronologists. If this is the case, then any reconstructions that use tree rings will tend to be worthless.
The effect of the selection method in question can be seen quite clearly in this IPCC spaghetti graph of temperature reconstructions. Notice how the separate reconstructions come tightly together in 20th century because their chronologies have been selected based upon their matching the surface temperature record. But then moving to later times, they spread out dramatically because their sensitivity to temperature is no longer assured. The percentage of trees that are sensitive to temperature has fallen, and the number of trees that are sensitive to temperature in any given reconstruction can vary widely. How useful are they when there is a .8C variation between them at some points.
“We remove any series that was not positively correlated with it “local” temperature observations [taken from the nearest grid box of the HadCRUT2 temperature data set (S9)]. The series used by (S3) were already screened for positive correlations against their local annual temperatures, at the decadal time scale (Table S1). We removed series from (S1) that did not correlate positively with their local annual or summer temperatures (Table S1), or which did not extend into the period with instrumental temperature to allow a correlation to be calculated. The series from south-west Canada (named Athabasca) used by (S1) did not correlate positively with local temperature observations, but has been replaced by a new, better-replicated series (S10) that does correlate very highly with summer temperature (Table S1) and has also been RCS-processed to retain all time scales of variability"
Now here is a quote from Briffa responding to Steve McIntyre’s criticism of his Yamal chronology.
"Chronologies are constructed independently and are subsequently compared with climate data to measure the association and quantify the reliability of using the tree-ring data as a proxy for temperature variations."
Now, one would think that this would be a good selection method if we wanted to use tree ring reconstructions to tell us 20th century temperature. But actually, it doesn’t even do that. The chronology simply mimics the surface temperature record; right or wrong.
But the real purpose of a reconstruction is to give us an idea of the relative temperatures of different periods of history. Especially those were we had no thermometers. And for that purpose, the selection method described by Osborn and Briffa absolutely destroys the value of the reconstruction.
It is clear from the descriptions of dendrochronologists themselves, as well as from what we know about tree growth, that trees do not all grow at the same rate, and the same tree grows at different rates throughout its life. One of the factors effecting its growth is temperature. But there are many others – sunlight, nutrient, water, CO2 availability etc. At any given point in time a tree may be able to respond to increases in temperature, or it may have it’s growth limited by a problem with the other factors. So, over the course of the life of a tree it may change it’s growth rate because it’s roots have reached a new source of nutrition; because the flow of water on the hillside where it is growing has slightly changed giving it more or less of the stuff; because a nearby tree has died giving it more sunlight; because a nearby tree has grown giving it less sunlight; because a nearby tree has died and it’s carcass is feeding the tree; because some bears have decided that it’s a good place to relieve themselves, etc. So let’s say that at any point in time a tree has a 60% chance of responding properly to temperature variation because it has the other resources that it needs. The number could be 20% or 80% - for purposes of this example it doesn’t matter.
So now, when we are in a period of increasing temperature, we select the series or the chronologies, as the case may be, that reflect that temperature rise. This means that 100%, or nearly 100% of the trees in the 20th century portion of the chronology are responding to temperature. If the number is much smaller, then only a fraction of the temperature rise will be reflected. But what happens to other historical periods within that chronology. The selection process did absolutely nothing to insure that those same trees were responding to temperature in say the Medieval Warming Period. So the likelihood that they are responding correctly to temperature tends to move towards our theoretical 60% average for those later periods. This means that by using Briffa and Osborn’s selection process, you are introducing a huge bias for having the 20th century show much more warming than the MWP. In fact, if the 20th century turns out to have anywhere close to the warming of the MWP, it will produce a chart where the 20th Century shows up as being much warmer than the MWP. And Al Gore can claim “unprecedented warming” for the 20th century.
I don’t know if Osborn’s and Briffa’s selection methods are unique to them. I rather doubt it. Most likely they are used by all of the dendrochronologists. If this is the case, then any reconstructions that use tree rings will tend to be worthless.
The effect of the selection method in question can be seen quite clearly in this IPCC spaghetti graph of temperature reconstructions. Notice how the separate reconstructions come tightly together in 20th century because their chronologies have been selected based upon their matching the surface temperature record. But then moving to later times, they spread out dramatically because their sensitivity to temperature is no longer assured. The percentage of trees that are sensitive to temperature has fallen, and the number of trees that are sensitive to temperature in any given reconstruction can vary widely. How useful are they when there is a .8C variation between them at some points.
Thursday, October 1, 2009
Briffa Yamal data debate
Saturday, January 10, 2009
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