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Climategate: Tampering with Temperatures?

Posted on 20 November 2010 by James Wight

This is the second part in a series on the fake scandal of Climategate (start here).

The first set of allegations against the University of East Anglia Climatic Research Unit (CRU) concern its main area of research, the instrumental temperature record CRUTEM. The CRUTEM analysis is very similar to those produced by independent groups such as NASA’s Goddard Institute for Space Studies (GISS) and NOAA’s National Climatic Data Center (NCDC). Nevertheless, the contrarians allege that CRU manipulated data to fabricate a global warming trend; that CRU prevented critics from accessing the raw data and other information required to check its conclusions; and that CRU director Phil Jones failed to admit having cited fraudulent data twenty years ago. Thus they claim CRUTEM cannot be trusted.

To create the CRUTEM surface temperature analysis, CRU scientists take temperature data from 4,138 stations, and for each station they calculate the mean temperature for 1961-1990 and temperature anomalies relative to that period. They then arrange all this data into a 5x5 degree grid. This process requires that adjustments be made to account for sources of error such as changing station locations or urban heat island effect.

Following Climategate, several amateur climate bloggers have attempted their own analyses of global temperature trends, and arrived at very similar results to CRU, GISS, and NCDC. The Muir Russell Review took a similar approach, going back to primary sources and obtaining raw station data to see if it was possible for critics to replicate CRU’s results. They were able to acquire as much data as necessary from both the Global Historical Climatology Network (GHCN) and the National Centre for Atmospheric Research (NCAR). They proceeded to write the computer code needed to analyse the data in the space of two days, without requiring any information from CRU.

Thus the Review demonstrated that CRU was not hiding anything: sufficient data was available to replicate CRU’s results, and any competent researcher would be able to analyse it. Furthermore, they had nothing to hide: both adjusted and unadjusted data yielded very similar results to CRUTEM, and CRU’s homogenisation adjustments make no significant difference to the global average. Although the Review stopped short of drawing scientific conclusions, it appears that CRU’s conclusions are robust. So Climategate is not “the final nail in the coffin of anthropogenic global warming”.

Based on this, the Review concluded (its emphasis):

CRU was not in a position to withhold access to [temperature] data or tamper with it. We demonstrated that any independent researcher can download station data directly from primary sources and undertake their own temperature trend analysis.

On the allegation of biased station selection and analysis, we find no evidence of bias. Our work indicates that analysis of global land temperature trends is robust to a range of station selections and to the use of adjusted or unadjusted data. The level of agreement between independent analyses is such that it is highly unlikely that CRU could have acted improperly to reach a predetermined outcome. [1.3.1]

This is stated more explicitly in Chapter 6:

It is impossible for a third party to tamper improperly with the data unless they have also been able to corrupt the GHCN and NCAR sources. We do not consider this to be a credible possibility, and in any case this would be easily detectable by comparison to the original NMO records [6.4]

Of course, this means nothing to the diehard conspiracy theorists, but hopefully it will help to convince the public.

The Review also considered the availability of metadata; that is, whether there was enough information available to identically replicate CRUTEM. As noted above, the computer code was no problem. Getting an exact list of temperature stations included in CRUTEM was more of an issue. Such a list was provided with the first version of CRUTEM in 1986, but CRU neglected to update it in the latest version, CRUTEM3, published in 2006.

An up-to-date list was not released until October 2007, in response to an FoI request. Even then, the Review Team found it was not straightforward to identify all the stations, due to a lack of standardisation. However, 90% could be matched with stations in the GHCN database, and CRU informed them that the remaining 10% could be obtained from other sources such as the relevant National Meteorological Office. As a “test case”, the Review did obtain data directly from the Japanese NMO.

The Review makes the following criticism of CRU:

CRU should have made available an unambiguous list of the stations used in each of the versions of [CRUTEM] at the time of publication. We find that CRU’s responses to reasonable requests for information were unhelpful and defensive. [1.3.1]

The inquiry also briefly dealt with the allegation “that Jones was complicit in malpractice in failing to respond appropriately to allegations of fraud made against […] Professor Wei-Chyung Wang”, whose data Jones cited in a 1990 paper on the urban heat island effect. The allegedly “fabricated” claim was that few if any of a certain selection of Chinese weather stations had moved over time. Wang’s university investigated and rejected the accusation of fraud. Meanwhile, Jones admitted that the stations “probably did move” and responded within one year with a peer-reviewed analysis confirming the original conclusions. In any case, this was only one paper and does not change anything we know about the urban heat island effect.

The overall implication of the allegations was to cast doubt on the extent to which CRU’s work in this area could be trusted and should be relied upon and we find no evidence to support that implication. [1.3.1]

Next: Hiding the Decline?

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Comments 1 to 14:

  1. James, you make some excellent points, inconvenient points that I am sure will be lost and/or dismissed by the skeptics. One of the many things that I find ironic about the CRU faux scandal, is that on the one hand the "skeptics" are claiming that Jones et al fudged the data, but on the other Lindzen, Michaels and others have recently cited the HadCRUT data. In fact, Michaels showed the HadCRUT data in his misleading testimony to congress earlier this week. And we know why that is; HadCRUT is very likely underestimating the rate of warming: "The ECMWF analysis shows that in data-sparse regions such as Russia, Africa and Canada, warming over land is more extreme than in regions sampled by HadCRUT. If we take this into account, the last decade shows a global-mean trend of 0.1 °C to 0.2 °C per decade. We therefore infer with high confidence that the HadCRUT record is at the lower end of likely warming." The 'skeptics' and those in denial about AGW are now even turning on their beloved UAH MSU data now that it is allegedly being "stubborn". The incoherence and inconsistency of the "skeptics'" actions and arguments continue to amaze.
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  2. Some of the observational data that CRU held did not have restriction about re-distribution, but some others had. Let me call them "open source" and "closed source", though this is not about computer program codes, because the situation is analogous. CRU refused to give the closed source data because of the conditions given by the organizations which provided the source data. (CRU was also reluctant to give the open source data as responses to freedom of information requests, because they think that providing source data is not their job, but of data centers such as U.S. National Climatic Data Center.) As for global scale syntheses aimed at global mean or hemispheric mean temperatures, we now know that open source data are enough for us to reproduce essentially the same results which CRU achieved by a mixture of open and closed sources. That is a good news, but it does not mean that scientists should always avoid closed source data. We (scientists etc. of the world) still need data from high density observation networks in order to study regional climate changes. And they are often closed sources. Very regrettably, many governments think about potential economic returns by intellectual property rights more seriously than about freedom of information or transparency in environmental assessments. (People gathered at Surface Temperatures project discussed the way how to make use of closed source data.) The case of urban effects in China really needed closed source data, and obscureness around it mainly comes from the policy of the Chinese government which discloses information about only those stations selected for international exchange.
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  3. Besides the numerous replications of the temperature record, see also these two links showing that CRU’s data handling has not inflated the warming trend:
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  4. "The Review took a similar approach, ..." Which review is being discussed here? There have been quite a few reviews of different aspects of the "climategate" non-sense so it's worth being clear. Albatross: I don't suppose it's that important but note that this article is talking about CRUTEM (which is the land-only dataset compiled by the Climatic Research Unit) and is only a component of the HadCRUT which also includes the sea-surface temperatures from the Hadley Centre.
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    Moderator Response: Sorry, I meant to say the Muir Russell review. The full context is given in the first post in the series. - James
  5. Re: Ed Davies (4) The Review would be the independent Muir Russell Commission. Link here. The Yooper
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  6. Ed @4, Thanks for picking up on that. I checked Michael's testimony again and he does not specify which records he is using-- he refers to using the CRU surface temperature data or using data from the Hadley Centre. So it looks like he may have been using both HadCRUT and CRUTEM, the fact that he did not uses the accepted nomenclature does not help. Anyhow, the whole point is the irony of the "skeptics" making (fallacious) claims as to the integrity of the CRU and CRU data, but then going on ahead and using those data repeatedly because they are underestimating the amount of warming.
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  7. For "skeptics", the temperature record is reliable just as long as it supports "cooling" or "no warming". If Phil Jones says the last 15 years had no warming trend to the 95% confidence level, then the record is spot on. If someone says it stopped in 1998, then NASA, NCDC and CRU are beyond suspicion. But if you point out the obvious long term warming trend, then it's just a bunch of numbers made up by the secret brotherhood of the warmist scientists.
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  8. Folks, this post, among other things, should show you how utterly *incompetent* Anthony Watts and his "" crew are. The "surfacestations" project has been active for *over three years*. And in the three+ years of project's existence, nobody affiliated with it has been able to produce even *one* cursory analysis of temperature data collected by the stations. This, in spite of the fact that the temperature datasets are no more than a few mouse-clicks away for anyone smart enough to figure out how to use a web-browser. It would have been a simple matter for the surfacestations folks to download and crunch the temperature data from the stations as they were conducting the survey. And it would have been almost a "no brainer" for them to compare temperature data collected from "well-sited" vs. "poorly-sited" stations in order to confirm or disprove their claims about temperature data quality. But in 3+ years' time, nobody affiliated with the project has done that -- this in spite of the fact that the gridding/averaging procedure is a task that capable undergraduate compsci/engineering students would have no problem implementing. It was left to others to perform the analysis work that the lazy and/or incompetent surfacestations folks were unwilling or unable to perform. The fact that the Muir Russell commission was able to do in *two days* what the Anthony Watts' and his surfacestations crew were unable to do in 3+ years should be a reminder to one and all how lazy and/or incompetent the folks who have been attacking the surface temperature record are. The surfacestations project is a complete joke; all the people associated with that project should be presumed incompetent until they can demonstrate otherwise.
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  9. caerbannog @8, "all the people associated with that project should be presumed incompetent until they can demonstrate otherwise." That would include Pielke Snr.... To be fair though, Watts et al. claimed recently that they have submitted something for publication.
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  10. I think the UK could learn a lot from the US in terms of data availability. All data that has been funded directly or indirectly by the tax payer should be readily available to everyone. The availability of rainfall and flow data is also pretty poor, although it is improving. I also get a bit annoyed with the time spent on disproving deniers when we should be working on mitigation and adaptation.
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  11. Hyperactive Hydrologist : "All data that has been funded directly or indirectly by the tax payer should be readily available to everyone." The problem isn't the generated data, the CRU has always made that available, the problem is the source data, that is owned by different nations. The UK isn't responsible for data licensing for say China or other nations. Also what if a government lends money for research that gives a UK company an edge on its competitors. If that research became public, then competitors that have their head offices in other countries could take advantage of research funded by UK tax payers! The issues aren't as simple as you suggest.
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  12. caerbannog @6:02 AM, I'd be willing to bet the the folks HAVE done the necessary calculations. They just haven't published the results because the results don't agree with their desired outcome.
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  13. Re: Hyperactive Hydrologist (10) Having been an employee of the US Government (Department of Defense), I can certainly guarantee that not anywhere near all of the data collected by my former employer is readily available to anyone, despite being acquired at taxpayer expense. The Yooper
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  14. Yep #12 seconded
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