In October 2012, 135 months ago, Michael Mann initiated a libel suit against Mark Steyn and Rand Simberg, alleging that the two writers had defamed him by debunking as fraudulent his most famous contribution to the so-called debate over human-caused climate change — the hockey-stick graph. The trial finally got underway in Washington DC on January 16 — this year..The graph, which was introduced by Mann and two other authors in Nature magazine in 1998, purports to show a millennium of temperature changes in the northern hemisphere. The first nine hundred years or so, the handle of the hockey stick, is more or less flat. Then, at the dawn of the twentieth century, the blade of the stick shoots up, indicating a massive increase in global surface temperatures that coincides with increased hydrocarbon use and the production of carbon dioxide.The graph was featured in a 2001 UN report by the Intergovernmental Panel on Climate Change (IPCC) in support of the notion of “CO2 forcing,” as climatologists say, leading to the current hysteria and panic regarding human-caused climate change.Readers who are interested can view the trial online (at Watch the Ongoing Mann-Steyn Trial Live – Watts Up With That?). Mark Steyn’s opening statement, which is very funny, is also worth reading (Mark Steyn's Opening Statement : SteynOnline ), as is his original article in National Review (https://www.nationalreview.com/corner/football-and-hockey-mark-steyn/). Here I would like to provide a little context for Michael Mann’s litigiousness.When Mann published his paper and a second one in Geographical Research Letters the following year, there were about 500 papers in print that discussed the Medieval Warm Period and about 1,500 papers on the later (ca. 1500) Little Ice Age. The former was nearly a degree Celsius warmer than today, the Little Ice Age about a half degree cooler.The implication was obvious. If there was a period warmer than today, the importance of CO2 as an agent of climate change had obviously been exaggerated. If an earlier period was colder and then ended, maybe natural causes were involved. The hockey stick graph was designed to obliterate both climate “anomalies.”In fact, political climatology began in the 1970s with the UN Environmental Program, chaired by Maurice Strong, who developed a research mandate to understand “the scientific basis of risk of human-induced climate change,” and what could be done about it. This was a precursor to the IPCC. The most notable aspect of its mandate and that of the IPCC was that natural causes were excluded from consideration. Only the question of anthropogenic climate change was considered.Even better, if human-caused CO2 production caused the hockey stick blade to shoot up, we know what had to be done: go after big coal and big oil. In Canada, that meant go after Alberta.The Chrétien government did its part in 1998 by sending posters of hockey stick graphs to every high school in the country. They also claimed that 1998 was the hottest year in the millennium and sent a pamphlet to every household announcing that “fact.” The objective was to drum up support for the Kyoto Accord, which added a great deal to the regulatory power of Ottawa.Then something quite unexpected happened. The hockey stick came to the attention of Steve McIntyre, a Toronto investment analyst. To him the hockey stick looked like a typical mining promotion: big increases in production are just ahead. Hence the upturned blade. Invest now!He was curious and asked Mann for his data, some of which Mann sent him.McIntyre then got in touch with Guelph economist Ross McKitrick, whom I have mentioned in earlier columns. McKitrick was on record, with Steve Essex, a physicist at Western, for criticizing Mann’s hockey stick.So now McKitrick joined McIntyre to examine Mann’s data. They, M&M, discovered that there was a lot of missing information from the surface temperature record and that Mann had used proxy data, some of which was derived from the thickness of bristlecone pine tree rings to indicate missing temperatures.This was a problem.First, because the computer algorithm Mann used wouldn’t work with missing data, but Mann used it anyhow.Second, the authors of the study of bristlecone pine tree rings explicitly said that tree rings were not proxies for temperature.Third, when M&M tried to replicate the handle of the hockey stick, they couldn’t.Mann said that was because they didn’t follow his computations. They didn’t because he refused to provide them with the computational code.Then M&M caught a break. While going through archived data on Mann’s website, which they had permission to do, they found a file written in Fortran, an early computer language that is practically unknown today. So, they opened the file and decoded what they found.The details are complex and technical, but the result isn’t. They found that the algorithm Mann used data-mines for hockey sticks. Sometimes the blade went up, sometimes down, but it’s always there.They proved it by feeding an array of random numbers into the program and what do you know? A hockey stick resulted!This is sometimes called a Red Noise Test. If you run a set of random numbers through a computer program, you should get a set of random numbers out after the program does its thing. M&M then concluded that it wasn’t the data that showed a hockey stick but the technique Mann used to analyze the data that produced a hockey stick.M&M also found a file, which Mann had labelled “Censored.” It contained data without the bristlecone pine data. So, they ran it to see what came out. The answer was: no hockey stick and a return of the Medieval Warm Period.That is, Mann already knew what M&M discovered. The hockey stick depended on including the bristlecone pine data that had nothing to do with climate change. Mann then said that their remarks were “not helpful.” No kidding.This is not the first time Mann has defended his questionable behaviour in court. In 2011 he sued Tim Ball, a climatologist from the University of Winnipeg, for famously saying that Mann belonged in the state pen, not Penn State, his employer at the time. The BC Supreme Court exonerated Ball and awarded him full legal costs, but Mann refused to pay.Ball, whom Mann called a “human piece of sh—t,” paid his own costs and, when he died bankrupt in 2022, his funeral was crowd-funded. Mann has never paid a nickel of his legal costs and has never said who his sugar-daddy is. This is serious lawfare.There are many other things one might say about Michael Mann. Tune into the trial. Perhaps Mark Steyn will utter a few of them.