The Climate Conspiracy Exposing the deceit of climate scientists

The Real “Divergence Problem”

So, we've all read Phil Jones' infamous ClimateGate email about the trick to "hide the decline." The original email is available here.

From: Phil Jones
To: ray bradley, mann@virginia.edu, mhughes@ltrr.arizona.edu
Subject: Diagram for WMO Statement
Date: Tue, 16 Nov 1999 13:31:15 +0000
Cc: k.briffa@uea.ac.uk,t.osborn@uea.ac.uk

Dear Ray, Mike and Malcolm,
Once Tim's got a diagram here we'll send that either later today or
first thing tomorrow.
I've just completed Mike's Nature trick of adding in the real temps
to each series for the last 20 years (ie from 1981 onwards) amd from
1961 for Keith's to hide the decline. Mike's series got the annual
land and marine values while the other two got April-Sept for NH land
N of 20N. The latter two are real for 1999, while the estimate for 1999
for NH combined is +0.44C wrt 61-90. The Global estimate for 1999 with
data through Oct is +0.35C cf. 0.57 for 1998.
Thanks for the comments, Ray.

Cheers
Phil

In this post I will briefly describe what the alarmists claim "hide the decline" means, then show what it actually means, and then demonstrate the real problem the alarmists face. There are already two expert demonstrations of "hide the decline". One is at American Thinker (also this from AT) and the other is at Climate Audit.

First, we will look at Phil Jones' official explanation from November 23, 2009 for his use of the word "trick."

The word 'trick' was used here colloquially as in a clever thing to do. It is ludicrous to suggest that it refers to anything untoward.

So Phil Jones' position is that the word "trick" did not mean to imply anything deceitful. That is the whole of his attempt to explain away this quote. "Hide the decine" was never addressed in this apology. Alarmist apologists have furthered Jones' explanation by saying that the "hide the decline" was an attempt to deal with the "divergence problem."

What is the divergence problem? Before I explain that, I need to give you a very brief introduction to something called dendrochronology.

Dendrochronology (dendro = tree; chron = time; ology = study of) is the scientific method of dating based on the analysis of patterns of tree-rings. Dendrochronologists study tree rings and attempt to reconstruct past temperature data from them. Since we did not have accurate thermometer records prior to 1850-ish we have to rely on other sources of data for temperature information. These other sources are called proxies. One such proxy are these tree rings.

To determine the temperature, the dendrochronologist looks at the width of the tree rings. They believe that a wider tree ring indicates a greater growing season which means greater temperatures. What has not been discussed is how they disentangle other factors that influence tree growth, such as amount of sun light, fertilization, and CO2. There is no known method to disentangle this information. But they assume anyways that the wider tree rings means a higher temperature (instead of it meaning greater exposure to sunlight, greater availability of fertilizer, or any quantifiable increase in CO2.)

To see if these tree ring temperature reconstructions are accurate they are validated against the past 160 years of thermometer temperature records. Below is an example. The three colored lines that look like spaghetti are the tree ring proxy reconstructions. The black line is the thermometer temperature record.

You can look at this yourself and see whether they match up reasonably well or not. They appear to match up quite well from 1900-1950, where the graphs ramp upwards (the reality behind this is rather dubious, but that's a subject for another post.) Around 1960 the tree ring reconstructions greatly diverge from the thermometer record. You can see the green line declines while the thermometer record ascends. You can also see that the red and blue lines diverge from the temperature record, although they don't dip quite as bad as the green line. This non-agreement of the tree ring reconstructions with the thermometer record is the "divergence problem."

Why is this problem important? If they can not give accurate temperature measurements in recent years, how can they be trusted to give accurate temperature measurements for the past? If the tree-ring reconstructions could not read the higher temperatures of today, how can these scientists be sure that there weren’t higher temperatures throughout the last thousand years that have also gone undetected by the tree-rings? If they can not give accurate temperature measurements for the past, then how can these reconstructions be used to belittle the Medieval Warm Period?

To date, dendrochronologists have not been able to reconcile this divergence problem of the tree ring record from the thermometer record.

This ClimateGate email (1141398437.txt) on the subject is rather telling:

From: Richard Alley

Know anything about the "divergence problem" in tree rings? R D'arrigo talked to the NRC yesterday. I didn't get to talk to her afterward, but it looked to me that they have redrilled a bunch of the high-latitude tree rings that underlie almost all of the high-res reconstructions, and the tree rings are simply missing the post-1970s warming, with reasonably high confidence. She didn't seem too worried, but she apparently has a paper just out in JGR. It looked to me like she had pretty well killed the hockey stick in public forum--they go out and look for the most-sensitive trees at the edge of the treeline, flying over lots and lots of trees that are lesss sensitive but quite nearby, and when things get a little warmer, the most-sensitive trees aren't anymore, and so the trees miss the extreme warming of the recent times, and can't reliably be counted as catching the extreme warmth of the MWP if there was extreme warmth then.

Because as far as I can tell the hockey stick really was a tree-ring record, regardless of how it was labelled as multiproxy, this looks to me to be a really big deal. And, a big deal that may bite your chapter [of the IPCC report]...

--Richard

So, we know now what Phil Jones claimed he "meant" by using a "trick." We also have seen what alarmists say the divergence problem is. We have shown that dendrochronology indeed suffers from the divergence problem, and that because of this we can not accept their reconstructions to accurately give us important temperature information from the past.

So, now let's look at what he meant by "hide the decline." This get's complicated, because his one sentence is so telling and actually covers so much material.

I've just completed Mike's Nature trick of adding in the real temps to each series for the last 20 years (ie from 1981 onwards) amd from 1961 for Keith's to hide the decline.

He is saying that he completed Mike's trick. This means that there are two tricks. Mike's trick, and then Phil's trick.

First we will look briefly at Mike's trick. Mike in this case is Michael Mann, the inventor of the now-debunked hockey stick, and probably the biggest bully (as revealed in the ClimateGate emails) in climate science. Mann's "trick" has already been covered expertly by Steve McIntyre so I invite you to read his link for a full explanation. I will only show the relevant graphics and briefly explain them.

A graphic was needed for the Intergovernmental Panel on Climate Change's (IPCC) Third Assessment Report. The ClimateGate dendrochronologists wanted to make the graphic illustrate several different tree ring reconstructions that all showed that temperatures were spiking upwards in recent times. The first graph they assembled was this:

You can clearly see that Briffa's data (in yellow) did not match up well with the data from Mann and Jones. They pressured him to alter his graph to show more global warming, as evidenced in this email:

A proxy diagram of temperature change is a clear favourite for the Policy Makers summary. But the current diagram with the tree ring only data [i.e. the Briffa reconstruction] somewhat contradicts the multiproxy curve and dilutes the message rather significantly. [We want the truth. Mike thinks it lies nearer his result (which seems in accord with what we know about worldwide mountain glaciers and, less clearly, suspect about solar variations). The tree ring results may still suffer from lack of multicentury time scale variance. This is probably the most important issue to resolve in Chapter 2 at present.

To which they received this reply from Keith Briffa:

I know there is pressure to present a nice tidy story as regards ‘apparent unprecedented warming in a thousand years or more in the proxy data’

Much discussion ensued, and eventually Briffa caved and then we ended up with this graphic being published in the report:

If you look rather carefully, you can see that Briffa's data has been moved so that it is more in line with what Mann and Jones had. Also, in this graphic, the decline in Briffa's data has been eliminated. You can clearly see that it trends up with the rest of the data, and then you don't really see it anymore. You no longer see the big decline. In other words, it is hidden.

This blow-up of the graphic clearly shows where it is hidden:

You can clearly see, that rather artfully, and extremely deceitfully, Michael Mann cut off the decline of the graph, and hid the truncation of Briffa's data behind the rest of the lines.

If you think this is a misrepresentation of what Mann did, look at this before and after of Briffa's data:

The red line shows Briffa's data. The green line shows how Briffa's data was represented in Mann's graphic. You can clearly see that the temperature decline in the reconstruction was truncated.

Now, let's look at Phil Jones' trick. Again, this was expertly covered by American Thinker previously. Phil Jones was preparing a graphic for an upcoming World Meteorological Organization report. This wasn't just a tiny graphic in the report. It is featured on the cover of the report, and you can download the report here to see it for yourself.

When we look at this image, we see three lines that go back about 1,000 years. As the lines move toward the present we see the lines all shoot upwards. This conveys the message that these three lines all agree that the recent temperatures skyrocket upwards.

So let's look at the original data he was working with:

This is the same graphic we saw earlier. Note again that there are three tree ring proxy reconstructions shown in different colors, and then the thermometer temperature record shown in black. Look at the present time on this graph. You see the green line trend down sharply, the blue line trend flat, and the red line trend down then back up. Now look at the chart that Phil Jones published. These declines in the temperature data are absent! What happened?

You can clearly see that Phil Jones cut off the declining parts of the tree ring proxy reconstructions and spliced on the thermometer data. Where exactly did he do that? Let's look again carefully at what he said:

I've just completed Mike's Nature trick of adding in the real temps to each series for the last 20 years (ie from 1981 onwards) amd from 1961 for Keith's to hide the decline.

You can clearly see that he cut off Briffa's data (green line) around 1960 and spliced on the thermometer record, and he cut off his own and Mann's data (red and blue, respectively) at around 1980 and spliced on the thermometer record.

Clearly, he "hid the decline" in the temperature data. This method was never discussed in the World Meteorological Report. Never did he mention that he spliced tree ring data with thermometer data to give the impression that all of the tree ring data suggests recent warming.

This is as deceitful as you can possibly be. What makes this worse is that he emailed this to Bradley, Mann, Hughes, Briffa, and Osborn (look at the To: and Cc: lines of the original email.) This means that they were all aware of his "trick" and no replied that it was a very deceitful and dishonest thing to do. They were more than happy to go along with Jones' misrepresenting and misleading data.

So now we have seen for a fact that Phil Jones spliced thermometer data onto tree ring reconstructions, and we know for a fact that he sent the email admitting this to Michael Mann. That makes the following Mann lie so much more revealing of what a slimy, lying bastard he truly is:

No researchers in this field have ever, to our knowledge, “grafted the thermometer record onto” any reconstruction. It is somewhat disappointing to find this specious claim (which we usually find originating from industry-funded climate disinformation websites) appearing in this forum [realclimate].

It's funny that he blames these claims on "industry-funded climate disinformation websites." Sorry Mikey! We can all see that, without a doubt, you are lying. You got the email, you saw the report, you know it happened.

So, there we have it. Plain as day. We have seen how Mann truncated and hid the decline in his graphic, and then we saw how Jones cut off the declining parts of the tree ring reconstructions and grafted the thermometer record onto them. Two of the biggest names in climate science caught red-handed. By their own admission.

What does this show? Well, besides that the ClimateGate scientists are crooked, we see that dendrochronology, as a science, sucks and that it can not reliably detect warm temperatures. It is therefore impossible to use dendrochronology to rule out any previous warming episodes.

So, what is the real divergence problem that alarmists should be worrying about? It's the divergence between temperatures and CO2 levels.

As we have seen before, we are, without a doubt, experiencing nearly a decade of cooling. This is despite record high levels of CO2. Experts are now predicting that we should expect to continue on this trend for 20 or 30 years. The divergence between temperature and CO2 is only getting larger. This is the divergence problem they should be worrying about!