Posted by jlwile on November 27, 2009
If you have been paying attention to the news this week (and quite frankly, I’ve been having too much fun to be paying much attention), you probably know that an unknown hacker broke into the University of East Anglia’s Climate Research Unit (CRU) and released hundreds of confidential E-MAILs. 1 In fact, this has been such a big story that it already has its own Wikipedia entry.
What do the E-MAILs revealed by the hacker tell us? Partly, that depends on who you read. Some say they could be the “final nail in the coffin of Anthropogenic Global Warming.” 2 Others say they simply show “Scientists expressing frustration at the misrepresentation of their work in politicized arenas and complaining when media reports get it wrong; Scientists resenting the time they have to take out of their research to deal with over-hyped nonsense. None of this should be shocking.” 3
What do I think about these hacked E-MAILs? You can find out below the fold.
Probably the most important thing these E-MAILs reveal is how hard it is to truly understand what the temperature of the earth was long ago. For example, one of the E-MAILs contained this statement:
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.
If you don’t understand the context, “Nature” refers to the scientific journal, and “trick” refers to a statistical technique used by Michael Mann and his co-authors in a famous paper that Nature published back in 1998 4. This paper supposedly showed Northern Hemisphere temperatures over the past 600 years, and the trend indicated that the current temperatures are notably warmer than anything else over that time period. The data from this paper have been expanded over the years, producing the famous “hockey stick” graph, which supposedly shows that the temperatures in the Northern Hemisphere are abnormally warm, even when the past 1,000 years are considered.
(This graph appeared in the 2001 IPCC report)
So the quote from the E-MAIL indicates that a statistical technique was used in the work that generated the famous “hockey stick” graph as well as in some current work being done at the CRU. The technique is meant to “hide the decline” in global temperatures that have occurred since 1998.
Is that bad? Not really. In science, the word “trick” is often used to mean “method to take care of something annoying.” Scientists use “tricks” all the time. I think the only thing this E-MAIL indicates is that determining the temperature of the Northern Hemisphere over the past 1,000 years is very difficult. It involves measuring things other than temperature and then attempting to infer temperature from them. As a result, all sorts of “tricks” must be employed. In the end, depending on what “tricks” you use, you can come up with a graph like the one presented above, or a graph like the one presented below 5:
This is why I prefer to look at temperatures that have actually been measured. In addition, I like to look at truly global temperatures, which can only be measured by satellites. If we look at just these data, we see no appreciable global warming over the past 30 years6.
So while I don’t think these E-MAILs are a “nail” in the coffin of the hypothesis of man-made global warming, I think they clearly show that you must be very wary of believing temperature reconstructions from long ago. Since the people who produce such graphs are free to employ “tricks” to influence what those graphs ultimately look like, it is better to concentrate on real data. When you do that, you see no global warming.
I do want to point out one other thing about these E-MAILs, mostly because it reminds me of a commenter on this blog. In one E-MAIL, Phil Jones is complaining about a couple of papers that go against the view of man-made global warming. These papers were published in the peer-reviewed literature, but Jones doesn’t like what they say. Thus, he wants to keep them out of the next IPCC report. He says:
I can’t see either of these papers being in the next IPCC report. Kevin and I will keep them out somehow – even if we have to redefine what the peer-review literature is!
This is a common tactic employed by people who cannot answer data that go against their views. Rather than honestly looking at the data and trying to challenge it (or accept it), they try to “redefine” it so that it is “not science.” If you read the comments on this blog, you will recognize this as something “Norwegian Shooter” does very often. Rather than actually providing an intellectual argument for his position, he claims that all data contradicting his views are “unreliable.” One way he tried to do this was to actually redefine what peer review means – just as Jones describes in the above E-MAIL.
So these E-MAILs show scientists who are employing statistical techniques to “massage” the data and are discrediting any data that point away from their conclusion. To me, this simply demonstrates how incredibly weak their case really is.
1. Leo Hickman and James Randerson, “Climate sceptics claim leaked emails are evidence of collusion among scientists,” http://www.guardian.co.uk/environment/2009/nov/20/climate-sceptics-hackers-leaked-emails
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2. James Delingpole, “Climategate: the final nail in the coffin of ‘Anthropogenic Global Warming’?,” http://blogs.telegraph.co.uk/news/jamesdelingpole/100017393/climategate-the-final-nail-in-the-coffin-of-anthropogenic-global-warming/
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4. Mann, Michael E.; Bradley, Raymond S.; Hughes, Malcolm K., “Global-scale temperature patterns and climate forcing over the past six centuries”, Nature392: 779–787, 1998
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5. Loehle, C. and J.H. McCulloch, “Correction to: A 2000-year global temperature reconstruction based on non-tree ring proxies”, Energy and Environment 19: 93-100, 2008
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6. Global Hydrology and Climate Center, University of Alabama http://vortex.nsstc.uah.edu/data/msu/t2lt/tltglhmam_5.2
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