The Hockey Stick and the Mann v. Ball Libel Suit

By 2007, the MBH98/99 papers had been thoroughly investigated. The MBH hockey stick was found to be robust to statistical method and it was replicated by multiple other reconstructions (above, and discussed here, here and here). After the CRU emails were hacked and published, a new set of conspiracy theories were popularized on blogs and YouTube - these were based on a misreading of various emails (discussed here and here), but contrarian rhetoric was ramping up to a frenzy. Mann was frequently labeled a criminal and fraud, the hockey stick was called a scam or a hoax. 

The Mann v Ball Libel Suit

In an interview with the Frontier Centre for Public Policy (FCPP), Tim Ball was asked, "Various government and academic agencies have whitewashed the Climategate scandal so far. Do you think anyone will be prosecuted for fraud?” Tim Ball's response was, “Michael Mann at Penn State should be in the State Pen, not Penn State.” This was posted on the FCPP website and a series of letters to their supporters. On March 25, 2011, Mann filed suit against Ball and the FCPP in the Supreme Court of British Columbia. The complaint claimed that

The defendants have been guilty of reprehensible, insulting, high-handed, spiteful, malicious and oppressive conduct, and such conduct by the defendants justifies the court imposing a substantial penalty of exemplary damages on the defendant and an award of special costs in favour of the plaintiff, in addition to an award of general damages for injury to reputation.

Personally I'm not a fan of these types of libel suits for a couple reasons. First, to demonstrate libel, the defendants' must be credible enough to be believable by rational people such that significant damages can be inflicted on the plaintiff. And in another libel suit, Ball actually won because "a reasonably thoughtful and informed person who reads the Article is unlikely to place any stock in Dr. Ball’s views." Second, even if Mann were to win the suit, it's difficult to see a way in which the victory would be a "win" in the court of public opinion. Contrarians would simply spin the loss as persecution - as an oppressive restriction of free speech and as an attempt to silence opposition. Libel suits like this give way too much attention to conspiratorial thinking, and personally I consider this suit rather trivial and petty (though admittedly I'm not in Mann's shoes and don't have to deal with constant attacks by conspiracy theorists).

At any rate, the case continued for years, but in June 2019, the FCPP settled with Mann, published an apology for publishing Tim Ball's lies, and retracted the statement. The FCPP admitted that Ball's words were "untrue and disparaging accusations which impugned the character of Dr. Michael Mann." They also said that they "now accept that it was wrong to publish allegations by others that Dr. Mann did not comply with ethical standards and wrong to suggest that Dr. Mann was guilty of any dishonesty concerning his 1998 and 1999 research which produced the so-called 'hockey stick' temperature graph." With this admission from the FCPP, perhaps it was only a matter of time before Ball would be forced to make a similar settlement. However, there were two periods of delay, totaling nearly 3 years altogether, that the court decided was an inexcusable, "inordinate delay." Mann's legal counsel said it was "occupied with other matters." By 2019, Tim Ball was in poor health, and three of the defendant's witnesses had died; a fourth was unable to travel. Ball's legal counsel petitioned the court for a dismissal, and it was granted with prejudice, and the court ordered the plaintiff to pay court costs (not Ball's legal fees). There was no verdict in favor of Ball. There was no decision that Ball was not culpable for libel. There was no ruling that Ball's statements weren't bald-faced lies. Instead, the court was sympathetic with the fact that Ball was in his eighties and in "poor health." The court even noted that Ball "has had this action hanging over his head like the sword of Damocles for eight years," suggesting that the court believed that Mann's case against Ball had real merit, but Ball shouldn't have the threat of a judgment against him hanging over his head for such a long time. The earliest date for a trial would have been in January 2021, making it 10 years since the the publication of Ball's lies. So the court had mercy on Ball, and he came out from under the sword of Damocles without a verdict against him.

The reason for Mann's delay appear to be largely unknown, other than being due to the "plaintiff's counsel being busy with other matters." The court found that excuse to be inadequate, since the overriding principle governing whether a delay is excusable has to do with "essential justice." The defendant should not be "deprived of his right to have his case decided on its merits unless he is responsible for the undue delay." Since four of the defendant's witnesses were unable to testify, since some witnesses may not have full memory of events 10 years later, and since Ball's health was failing, the court (probably correctly) found that a dismissal with prejudice was warranted.

The Aftermath of the Dismissal

The response on YouTube and in the blogosphere was astounding. They declared victory for Ball and a loss for Mann. WUWT claimed that "Mann 'hides the decline' again." Principia Scientific International (PSI), an organization founded by Tim Ball, even doctored a photograph of Mann to look like a mugshot with Mann holding a sign saying "climate criminal?" PSI then tried to make it appear like it was the hockey stick that was on trial, not Tim Ball: 

This extraordinary outcome will likely trigger severe legal repercussions for Dr Mann in the U.S. and may prove fatal to alarmist climate science claims that modern temperatures are “unprecedented.”

Hardly. The case was partially settled after FCPP admitted that Ball's statements were untrue and Mann wasn't guilty of any dishonesty, let alone fraud. But PSI suggested that the delays were due to Mann refusing to hand over data. PSI claimed that:

the case boiled down to whether Ball’s words (“belongs in the state pen, not Penn State”) after examining the key evidence (R2 numbers) fairly and accurately portrayed Mann. The aim was to compel the plaintiff (Dr. Mann) to show his math ‘working out’ to check if he knowingly and criminally misrepresented his claims by resorting to statistical fakery. ... Despite Ball’s best efforts over 8 years, Mann would not agree to surrender to an open court his math ‘working out’ – the R2 regression numbers for his graph.

This was picked up by a Powerline blogpost, popular among contrarians, that said it this way:

What happened was that Dr. Ball asserted a truth defense. He argued that the hockey stick was a deliberate fraud, something that could be proved if one had access to the data and calculations, in particular the R2 regression analysis, underlying it,' Hinderaker wrote. 'Mann refused to produce these documents. He was ordered to produce them by the court and given a deadline. He still refused to produce them, so the court dismissed his case.

These are all complete lies. While it's fair to say that Ball couldn't be liable of libel if they turned out to be true, FCPP had already admitted that Ball's words were "untrue and disparaging accusations which impugned the character of Dr. Michael Mann." The only question remaining was whether his lies were libelous. Neither Mann's papers nor his data were on trial; there was  no "order to produce" any data, and the case wasn't dismissed because of Mann's failure to produce data he was never asked to provide.  And this doesn't even make any sense. If Tim Ball had sufficient evidence to say that Mann belonged in the state pen in 2011, why would he need Mann to give him more evidence to justify his statement? Wouldn't that be an admission that his claim lacked merit with the evidence he had in 2011? The dismissal explicitly states that the case was dismissed because of delays by Mann's legal counsel, not because of any refusal to hand over data that was neither ordered nor required.

Let's Be Reasonable

The PSI response and the related responses from Powerline and WUWT are pretty astounding. There's nothing in the available court documents that warrants these claims, and in fact, the court documents these blogposts link to flatly contradict what their claims. It would seem that these bloggers are banking on the fact that most people won't click on these links and read them carefully. I have a few thoughts. Contrary to the claims by these bloggers:

1. Mann's data related to MBH98/99 had already been available online for several years before 2011, when Ball made his claims. Any data he needed to justify his claim in 2011 was already available to him then, so there was no need for Mann to turn over anything. You can find Mann's MBH98/99 data here and here. If Ball wanted the MBH08/09 data, he could have found it here and here and here.
2. Other papers were published before Ball lied to FCPP that successfully used the data from MBH98/99, including Zorita et al 1998[1] and Wahl and Ammann 2007(WA07)[2]. If Ball wanted the data for Wahl and Amman (which also included r^2 data), he could have found it here.
3. There's a helpful RealClimate blogpost that contains links to all the existing data that Ball could have wanted to see. These links were all contained on one post and easy to find. Ball had no excuse for not having any of this data in 2011, and the court had no need to ask Mann to turn over any data, since it was already available online.
4. It makes absolutely no sense that the FCPP would settle, apologize for publishing Ball's lies and retract Ball's statement if Mann was refusing to turn over data.
5. In Mann's response to Barton's questions in 2005, Mann clearly stated that he never produced r^2 values because they are not the correct statistical measure of skill. The statistical data that the bloggers claim Mann wouldn't hand over didn't even exist.  Here's Mann's detailed and lengthy explanation:
   

   I assume that what is meant by the “R2” statistic is the squared Pearson dot-moment correlation, or r^2 (i.e., the square of the simple linear correlation coefficient between two time series) over the 1856-1901 “verification” interval for our reconstruction. My colleagues and I did not rely on this statistic in our assessments of “skill” (i.e., the reliability of a statistical model, based on the ability of a statistical model to match data not used in constructing the model) because, in our view, and in the view of other reputable scientists in the field, it is not an adequate measure of “skill.” The statistic used by Mann et al. 1998, the reduction of error, or “RE” statistic, is generally favored by scientists in the field. See, e.g., Luterbacher, J.D., et al., European Seasonal and Annual Temperature Variability, Trends and Extremes Since 1500, Science 303, 1499-1503 (2004).
   
   RE is the preferred measure of statistical skill because it takes into account not only whether a reconstruction is “correlated” with the actual test data, but also whether it can closely reproduce the mean and standard deviation of the test data. If a reconstruction cannot do that, it cannot be considered statistically valid (i.e., useful or meaningful). The linear correlation coefficient (r) is not a sufficient diagnostic of skill, precisely because it cannot measure the ability of a reconstruction to capture changes that occur in either the standard deviation or mean of the series outside the calibration interval. This is well known. See Wilks, D.S., STATISTICAL METHODS IN ATMOSPHERIC SCIENCE, chap. 7 (Academic Press 1995); Cook, et al., Spatial Regression Methods in Dendroclimatology: A Review and Comparison of Two Techniques, International Journal of Climatology, 14, 379-402 (1994).
   
   The highest possible attainable value of r^2 (i.e., r^2 = 1) may result even from a reconstruction that has no statistical skill at all. See, e.g., Rutherford, et al., Proxy-based Northern Hemisphere Surface Temperature Reconstructions: Sensitivity to Methodology, Predictor Network, Target Season and Target Domain, Journal of Climate (2005) (in press, to appear in July issue)(available at: http://www.geo.umass.edu/faculty/bradley/rutherford2005.pdf).
   
   For all of these reasons, we, and other researchers in our field, employ RE and not r^2 as the primary measure of reconstructive skill.

6. Nevertheless, perhaps partly because McIntyre and McKitrick (M&M) had demanded r^2 data, they were calculated included in WA07, and Ball would have had access to r^2 data by consulting the paper[2] or the data for WA07 that was publicly available online here.
7. Incidentally, the fabrication that Mann failed to turn over r^2 statistics appears to have originated with M&M, and they still haven't given it up on this. In Nov. 2023, McIntyre wrote on his Climate Audit blog,
   

   Mann reported several statistics for the individual steps, but, as discussed over and over, withheld the important verification r2 statistic.  By withholding the results of the individual steps, Mann made it impossible for anyone to carry out routine statistical tests on his famous reconstruction.

   Some 25 years after the publication of MBH98, McIntyre is still accusing Mann of "withholding" results that Mann didn't even use.
8. Mann was never ordered to turn over his code, and Ball didn't require his code, and Mann's code was his own intellectual property, and he was compliant with US policies set by the National Science Foundation. Whether we agree with his decision to not release is own personal property or not, the fact remains he wasn't obligated to release it. This also was explained in Mann's written response to Barton:
   

   I have made available all of the research data that I am required to under United States policy as set by the National Science Foundation. In accordance with the rules promulgated by the Foundation and supported by the Foundation’s General Counsel, I maintain the right to decline to release any computer codes, which are my intellectual property.

The aftermath of the dismissal is one reason why I think it was unwise for Mann to even initiate this lawsuit. It's not libelous to lie. The standard for libel requires that the person have enough credibility such that his/her statements can cause damages, and Ball's credibility was very low. By suing Ball, he likely gave him and his statements more publicity than they would have had otherwise, and clearly neither Ball nor PSI were concerned about being truthful. Provided they stay under the threshold of what can be shown to be libelous in court, they can lie all they want. Ball's supporters are perfectly willing to lie; they have a reputation for trolling various blogs with extremist comments; even Roy Spencer has had to call out these "sky dragon slayers" for some of their more outlandish claims. These people don't need the publicity that a lawsuit gives them. These types of extremists thrive on just this kind of fake news, and this lawsuit gave them the opportunity to generate lots of it.

References:

[1] Zorita, E., F. Gonzalez-Rouco, and S. Legutke, Testing the Mann et al. (1998) approach to paleoclimate reconstructions in the context of a 1000-yr control simulation with the ECHO-G Coupled Climate Model, J. Climate, 16, 1378-1390, 2003.

[2] Wahl, E.R., Ammann, C.M. Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence. Climatic Change 85, 33–69 (2007). https://doi.org/10.1007/s10584-006-9105-7

https://cires.colorado.edu/outreach/sites/default/files/2020-03/Climate%20Resiliency%20HS4%20-%20Wahl%20ClimChange2007.pdf