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What do the hacked CRU emails tell us?

Posted on 22 November 2009 by John Cook

Earlier this week, the servers at the University of East Anglia were illegally hacked. Emails dating back to 1996 were stolen and leaked onto the web. Phil Jones, the director of the Climate Research Unit, has confirmed the emails are not forgeries although there is over 60Mb worth of material - they can't guarantee all of it is genuine. What does it all mean? Michelle Malkin labels it the global warming scandal of the century (of course the century is only 9 years old but even 'scandal of the decade' would be no mean feat). James Delingpole at the UK Telegraph claims the emails are the final nail in the coffin of 'Anthropogenic Global Warming'? So just what do these emails tell us?

Some of the emails must be embarrassing for the authors. One email responds in poor taste to the death of a well known skeptic. There's scathing discussion of skeptics such as Steve McIntyre and Roger Pielke, including imaginings of violence. However, the crucial question is whether these emails reveal that climate data has been falsified. The most quoted email is from Phil Jones in 1999 discussing paleo-data used to reconstruct past temperatures (emphasis mine):

"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) and from 1961 for Keith's to hide the decline."

What do the suggestive "tricks" and "hiding the decline" mean? Is this evidence of a nefarious climate conspiracy? "Mike's Nature trick" refers to the paper Global-scale temperature patterns and climate forcing over the past six centuries (Mann 1998), published in Nature by lead author Michael Mann. The "trick" is the technique of plotting recent instrumental data along with the reconstructed data. This places recent global warming trends in the context of temperature changes over longer time scales.

The "decline" refers to the "divergence problem". This is where tree ring proxies diverge from modern instrumental temperature records after 1960. The divergence problem is discussed as early as 1998, suggesting a change in the sensitivity of tree growth to temperature in recent decades (Briffa 1998). It is also examined more recently in Wilmking 2008 which explores techniques in eliminating the divergence problem. So when you look at Phil Jone's email in the context of the science discussed, it is not the schemings of a climate conspiracy but technical discussions of data handling techniques available in the peer reviewed literature.

In the skeptic blogosphere, there is a disproportionate preoccupation with one small aspect of climate science - proxy record reconstructions of past climate (or even worse, ad hominem attacks on the scientists who perform these proxy reconstructions). This serves to distract from the physical realities currently being observed. Humans are raising CO2 levels. We're observing an enhanced greenhouse effect. The planet is still accumulating heat. What are the consequences of our climate's energy imbalance? Sea levels rise is accelerating. Greenland ice loss is accelerating. Arctic ice loss is accelerating. Globally, glacier ice loss is acceleratingAntarctic ice loss is accelerating.

When you read through the many global warming skeptic arguments, a pattern emerges. Each skeptic argument misleads by focusing on one small piece of the puzzle while ignoring the broader picture. To focus on a few suggestive emails while ignoring the wealth of empirical evidence for manmade global warming is yet another repeat of this tactic.

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Comments 101 to 121 out of 121:

  1. Scientists are not naturally more honest than the rest of us. They don't have some natural immunity from falling in love with their own ideas, getting defensive in the face of criticism, or believing the idea that corresponds best to their own material well-being. No. What keeps scientist honest is skeptics looking over their shoulder, demanding their data, reproducing their results and critiquing their methods. What is damning about the CRU emails is that they show evidence of collusion designed to prevent anyone from checking their results by refusing to release data, and working to keep dissenting voices out of the journals so they could be dismissed as unpublished. People have noticed that Jones et. al. did not answer FOIA requests. It is a scandal that one scientist should have to submit a FOIA request to get data from another scientist, esp. a publicly funded scientist. And now CRU tells us they threw away the raw temperature data, so nobody can reproduce their results? People who behave like they have something to hide, usually do have something to hide. If Phil Jones et. al. were expert witnesses in a trial, the judge would have thrown their testimony out of court based on what the emails reveal.
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  2. When working with a dataset it will always happen that data is contaminated in someway or the other. Many times data can be filtered before use, but when a dataset is large it is prone to happen that bad or even faulty data slips into an experiment. Researchers are aware of this and when a result - or a data point - turns up significant, part of the protocol is to do a double check. This is part of the scientific methodology: if something is a relevant factor, an experiment must be conducted to rule it out. What is of scientific methodology concern in the CRU report is not the fact that there exists bad data or the operator has a lot problem to get it working, but the fact that there seams to be a loss of traceability in the experiment and thus it is not possible to do the required double check. This should make us concerned. CRU has received critics for not releasing its data set – which is common practice in science after publication. Other scientist want and will do a double check because in science "my word" for something is not good enough. It's been stated that the dataset has been unavailable due to that it is not ready for release, and this is a valid point to make because if data is released it should be provided in such format that it is possible to replicate the experiment with traceability in the data set – for reason already mentioned. The conclusion I make from the report is that the data set is not in such format right now, and this should make us very concerned.
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  3. Comment to response in comment #30: "The whole approach of Skeptical Science is to point out that global warming skepticism misleads by focusing on narrow pieces of the puzzle while neglecting the broader picture - the job of Skeptical Science is to communicate the broader picture." I am a bit concerned about your polarization in "narrow" respectively "broad" pictures. I think you are hijacking the meaning of these words which may not be agreed on by everyone. I don't think such attitude will do no more good than deepen the cliff between you and others peoples that may not agree with you to the single letter and point. Modern science is about reductionism and with such tool exclude things as wrong and leave the rest as "possible". When deferring skeptical criticism to be "narrow" and "cherry picking" you are also denying the scientists themselves the very same tool they are supposed to use to strengthen the rest of the scientific communities confidence in a theory as "possible". Implicit, the statement carry the meaning that any scientist that does cherry picking is not doing proper science. This is a very strange position to hold because our confidence in a scientific theory ultimately relies on all the "cherry picking" criticisms a theory is exposed to and is able to withstand.
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    Response: I appreciate your comments. Perhaps a more precise description would be that a common pattern in global warming skeptic arguments is to focus on narrow pieces of evidence while ignoring other evidence that contradicts their argument.
  4. I think this is the "divergence problem" John is refering to (hint: it's not a divergence problem):
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  5. Imo the use of the word skeptic in this context is misplaced. "skeptic" is a word that I find ambiguous. Skeptic toward science is not the same as being skeptic with in science, in where we associate skepticism with being rational as contrasted to a meaning of irrationality or ignornace. In the rational meaning all scientist are skeptics, even to their own ideas. What you describe/define I would not call skeptic, but dogmatic denial or irrational thinking.
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    Response: We could get in the whole argument about whether global warming skeptics should be labelled skeptic, denier, denialist, etc. But that just gets us off the science. So I'll concede the term 'skeptic' if it allows us to discuss real issues and not get in an argument on what we should be calling each other (never a constructive topic).
  6. Let's be clear as to exactly what the "trick" was. Steve McIntyre lays out the various steps as follows: Jones deleted the post-1960 values of the Briffa reconstruction, replaced them with instrumental values, smoothed the spliced series (see posts by both Jean S and myself proving this) and ended up with a reconstruction that looked like an accurate reconstruction of late 20th century temperatures. He didn’t merely show a temperature series alongside a proxy reconstruction, which is what the NAS panel did. The NAS panel had a different approach to the “problem” of the Briffa reconstruction. They simply didn’t show it. Many of these steps were not evident and were not adequately disclosed. Thus, the "trick" was much more than simply "plotting recent instrumental data along with the reconstructed data" as John Cook states above.
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  7. Steve McIntyre ... ipse dixit. (Sorry for the two out of maybe three latin words i know) :) Seriously, now thanks to McIntyre we know that there's nothing wrong in "hiding" the data when they are obviously not representative of the temperature. This is a small step back and good news indeed. We are left with a highly personal opinion (based on?) of "not evident" and "not adequately disclosed". Just a little effort away from "there's nothing relevant to us in that email".
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  8. @Riccardo--Do you dispute McIntyre's summary of the steps involved in "the trick"? And do you claim that Jones disclosed his methodology in the IPCC report? If so, then please be specific and set me straight. If not, then it shouldn't matter to you you whether I cited McIntyre's summary or someone else's. The facts speak for themselves. Res ipsa loquitur.
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  9. sgking, the facts speak for themselves, indeed; they just dropped the (know for years) useless data to make the graph. Period. Simple enough, unless one is trying to see the evil in any case and can always come up with specious accusation of some sort. P.S. The first sentence on McIntyre was just a joke, i apologize if i didn't make it clear enough.
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  10. @Ricardo--So, we are left with a highly personal opinion (based on ?) of "useless", but in this case I agree with you: The dropped data was indeed "useless" if one's objective is to create a hockey stick graph and "hide the decline" evident in the dropped data. In any event, how could Jones have known the data was "useless" if he couldn't explain WHY the tree rings no longer served as a useful proxy for temperature. Perhaps they never did? Perhaps tree ring width correlates more closely with some other variable related to but independent from temperature such as...I don't know...rainfall/humidity?
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  11. So Jones has resigned. UEA is conducting an enquiry into data 'misuse' The head of the world climate forum is also launching an enquiry. For an overview of the situation go here....
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  12. Also, I'd like to add that when proposing a theory, the onus is on those that aim to prove the theory correct, not on the skeptics. The skeptics provide very useful information in keeping all the scientific avenues open for exploration, and gradually theories that contradict the hypothesis may be brought down with carefully investigated evidence and with the utmost consideration... absence of politics.
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  13. no he hasn't Mizimi. He's stepped aside temporarily while the review takes place. That's pretty standard practice in this sort of circumstance. what strange places you go to, to source your "information"!
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  14. Actually Chris, my original source was the BBC news - it has also been reported in the paper press as a resignation, but I accept that UEA press statement says he has stood aside as Director "until the completion of the Independent Review to ensure that CRU can continue to operate normally and the Independent Review can conduct its work into the allegations"
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  15. Fantastic video on the hack! Posted on deSmogBlog.
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    Response: Thanks for the link - have added it to the Climategate page (and what the hey, have embedded it here for ease of viewing).

  16. And now greenman3610 has posted a video with a bit more technical detail (though with a bit less humor, unless you're a Beevis and Butthead fan).
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  17. John, Re my post 48 above, you stated there is "a greater than 90% chance that humans are causing global warming (I believe this actually understates the certainty)." This 90% chance or probabilty that you mention, is this at the 90% confidence level, 95% confidence level or some other confidence level? Can you please point me in the direction of the relevamt data so that I can check your claim statistically ?
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  18. I find it incredible that you would suggest that all the more than 31,000 scientists who signed the document refuting the concept of AGW, including 9,000 PhD's, and including geophysicists, oceanographers, meteorologists, astrophysicists, atmospheric scientists and climatologists, do not have the academic credentials to validate their views! Moreover, those signatories are all from the U.S.; assuredly there are many thousands more scientists internationally who agree as well. Re the recently exposed emails, when scientists work to stymie the efforts of their peers to obtain information, as has been revealed, it's the antithesis of scientific community and process. All scientists should be insisting on a thorough and transparent investigation.
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  19. To whom it may concern, Penn State inquiry finds no evidence for allegations against Michael Mann. Here the full report of the inquiry panel
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  20. The British Institute of Physics (IOP) has issued a statement following up its initial um... "controversial" advisory to Parliament. The initial advisory has been used by the denial blogosphere to claim that the IOP rejects the existence of anthropogenic global warming. The followup statement is intended to counter that misinterpretation.
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  21. Tom Dayton at 04:47 AM on 7 March, 2010 Turns out there are some problems with that evidence, including irony: 'Evan Harris, a member of the science and technology select committee, said: "Members of the Institute of Physics … may be concerned that the IOP is not as transparent as those it wishes to criticise."' More: Climate emails inquiry: Energy consultant linked to physics body's submission
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