Saturday, December 5, 2009

Climategate becomes more visible, data is analyzed

Slowly but surely greater attention is being given to the potential scandal that has acquired the “Climategate” label. There are 28.5 million results when I just typed that key word into Google. While the story was first carried in such news sources as Fox News, the Wall Street Journal, and the British Daily Telegraph it has only been much more recently that it has been recognized by others in the MSM. And while CNN is carrying the topic it appears to be slanting the coverage towards the AGW crowd.

This is not uncommon. For example on Friday there was a short mention of the topic on NBC though still doubting its significance. And analysis of the code by an expert was showing the existence of problems that has finally caught the BBC’s attention. Should you watch the BBC piece you might note that while the programmer highlights the words “fudge factor” on the screen, the reporter does not really cover what that means. Yet magazines such as Newsweek continue to offer apologia, rather than asking hard questions, and Nature, instead of explaining exactly how many folks reviewed papers on climate change topics, and whether the cartel really had the power the e-mails claimed to restrict papers, also defended their position editorially, raising the clear possibility that the reputation and integrity of one of the greater journals in science has been compromised.

And after being caught by Jon Stewart it has now reached the front page of the Washington Post (though it seemed to fall off the front page of the Internet edition rather fast).

Interestingly, however, one can pick up by the focus of the comments where the writers of the pieces are coming from. For example, with the Washington Post piece, it is accompanied by a side bar that shows the following graph:

The WAPO comment above the curve was “However, nine of the world’s hottest years have occurred this decade,” which the graph then illustrates.

Unfortunately this statement while obviously absolutely untrue, (there are a number of periods in the geological past that were significantly warmer) even in the context meant (likely that of the last say 2,000 years) is almost certainly wrong, and one of the underlying points revealed in the e-mails is that folk such as Dr Michael Mann appear to have known this. (It was apparently he who first came up with the trick of replacing the data from tree rings, which were starting to show an apparent decline in temperature, while the temperature was actually going up, with real temperature data.) Now there are several issues with this change that folk need to be aware of.

The first, and obvious one, is that if the proxy that is being relied on to predict temperature is not correctly recording temperature change, then the use of the proxy has to be questioned. If the folk who used it do not publically admit to this, then it is reasonable to raise a question both concerning their personal integrity and that of the published papers that they have generated. (Given the cross-exchange of e-mails it also brings others into this collusion to conceal information).

The second point is the one that scientists get fascinated with, and that is why did the proxy data stop being accurate? And one possible answer has been provided by Craig Loehle. To simplify his argument, he points out that the width of tree rings – assumed to be linearly related to temperature – will also be affected by other factors. For example it is not unreasonable to assume that, as temperatures rise above a certain point, that there will be less moisture in the soil, and thus the tree will increasingly suffer, rather than increasing to prosper. If such a case is so, above a certain temperature, then (as the data being used by Briffa showed the tree rings would start to shrink.

Proxy temperatures as predicted by tree-ring data as plotted by Steve McInyre from Briffa data.

Notice that, for the first time in the record the temperature rises above the zero line in about 1930. And then crosses it again in 1960, with the onset of the red part of the curve – which is the decline that has been deleted from the plot). If one looks at a recent Met Office plot of temperature for this period:

Met Office Plot of temperatures. (Sorry I could not get through to the site for a current reference. At present the popularity of the site is causing it to redirect traffic to the UEA announcement page).

One can see that temperatures have risen, at around that time, to lie above the baseline, where Dr. Loehle believes the inflection starts to occur. So that, in his projection, while the temperature continues to rise, the proxy (tree ring) data will fall:

Projection of variation in tree ring data, showing a projected false value for temperature, as increased temperature reduces soil moisture, and thus ring growth (according to Loehle).

The change from the debate about recent temperatures has some relevance, but it becomes much more relevant to the debate over the condition during the Medieval Warming Period. NOAA currently shows this chart, which comes from the 2007 IPCC report.

However what is worth a passing comment is that if one looks at the model predictions of temperature before about 1850 they clearly show that the models overestimate the actual temperatures, and that while the actual instrumented temperatures were showing a Little Ice Age back to 1500, the models and proxy data do not. And if one were to apply the Loehle logic to the data between 1000 and 1150 where some of the models show the temperature crossing the zero line, then one could project that within that period the temperature could be higher than projected.

The tree ring data came from the Western United States for that time period has been a critical part of the debate on the validity of the original Mann, Bradley and Hughes paper. But we know from Scott Stein’s work that the western United States went through two severe drought periods :
We now have compelling proof,” says Stine, “that Owens Lake dried up and became a desert playa in the early medieval period. The finding has ominous implications for the future security of Los Angeles' water supply.”

Two years ago, Stine caused a sensation in the science press with his claim that California had endured two epic droughts in the Middle Ages, one of 220 years (from 892 to 1112) and the other of 140 years (from 1209 to 1350). By contrast, the most severe recent drought— which created an unprecedented statewide water emergency— lasted only six years, from 1987 to 1992.

Stine's primary evidence, now broadly accepted, consists of ancient tree stumps that were exposed to view when the 1980s drought and DWP greed reduced water levels by more than 50 feet in Mono Lake (the northernmost catchment of the Los Angeles Aqueduct) and other Sierran lakes and streams.
I would guess that the severity of a drought of that duration would, as Dr. Loehle has pointed out, be enough to narrow the tree rings of the time. Perhaps now we might get a little more investigation of this point?

The point is now being caught by some of the reporters that are actually bothering to dig into the data, and so, for example, Christopher Booker who brings a different interpretation to the story that I have tried to tell in the above. But it goes back to the reliance of the Global Climate Models (GCM) on too little data as I explained in an earlier post back in October.

It is also sad to note a comment in the London Times coverage of the decision of the British Met Office to re-create all the data.
The Met Office plans to re-examine 160 years of temperature data after admitting that public confidence in the science on man-made global warming has been shattered by leaked e-mails.
The Government is attempting to stop the Met Office from carrying out the re-examination, arguing that it would be seized upon by climate change sceptics.
They have got to be kidding !! Even Al Gore knows when he has a problem.

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