Michael Mann, inventor of the Hockey Stick, has written to the Wall Street Journal branding me a “denier” and a “contrarian” and “silly.” These are badges of honour I shall wear with pride.

The letter is interesting for lots of reasons, not least its grotesque hypocrisy. “In recent years”, he writes, “attacks on climate science have become personal” – as if somehow the real victims of all this are not the innocent taxpayers being screwed to pay for the great green boondoggle, but ordinary decent climate scientists like Mann and his Hockey Team just trying to get on and do their job.

Every snowflake is unique, but attacks on climate science all seem the same. I should know. I’ve been one of the climate contrarians’ preferred targets for years.

Has Mann actually read any of the Climategate and Climategate 2.0 emails, I wonder? A lot of them have his name on them, so he must have done at one time or another. But perhaps with all that data-fudging and decline-hiding his brain has been overtaxed of late. So let us gently jog his memory with some examples.

Here’s one from New Zealand. (H/T WUWT) It’s 2003 and a Kiwi scientist called Chris de Freitas has published in a journal called Climate Research a meta-analysis by some Harvard astronomers Soon & Baliunas of all the papers that have been written on the Medieval Warming Period (MWP). The conclusion of Soon & Baliunas? That the vast majority of published, peer-reviewed papers on the MWP conclude that it was both geographically widespread (not, as Warmists and their amen corner in Wikipedia like to pretend, a little local anomaly confined to Northern Europe) and significantly warmer than now.

This irritates Michael Mann and his Hockey Team no end, for it contradicts their view that late 20th century warming is both unprecedented and catastrophic. So how do they respond? Do they counter it with new, learned papers demonstrating in closely illustrated detail just where Soon & Baliunas have got it wrong?

Of course they don’t!

Instead, what they do is gang up to shoot the messenger. They conspire to have Climate Research closed down; to have Chris de Freitas sacked; then, they write to the head of his university in Auckland to see if they can’t get de Freitas deprived of his living too. Nice!

Dr Pat Michaels has another good example of this delightful behaviour by members of Mann’s “Team.”

In Forbes magazine, he writes an open letter to the director of the National Center for Atmospheric Research in Boulder, Colorado, describing how one of his “most prestigious employees” Dr Tom Wigley sought to have Michaels deprived of his PhD.

Dr Wigley’s evidence for this potentially libellous claim, widely circulated to a large number of his fellow climate “scientists”? None whatsoever.

But hey, as Mann has taught us many times over the years, who needs evidence or facts when you can go straight in for good old character assassination instead.

This, though, is wearisomely familiar stuff to anyone who has been following the Climategate story. What’s perhaps more interesting about Mann’s WSJ letter is his citation of the lead-in-petrol example from a few years back to try to bolster the credibility of his own brand of climate junk science. As we’ll see, he may have cause to regret this.

Here’s what he says in the letter:

Climate scientists can also find kinship with Dr. Herbert Needleman, who identified a link between lead contamination and impaired childhood brain development in the 1970s. The lead industry accused him of misconduct. Later, the National Institutes of Health exonerated him.

Hmm. The Needleman affair is covered very thoroughly in Christopher Booker’s and Richard North’s Scared To Death (Continuum). It does not reflect at all well on the junk science scare industry.

Dr Herbert Needleman was a US child psychologist who generated headlines in 1979 with his research paper showing that lead poisoning was dramatically affecting children’s IQs. This “evidence” became a vital plank in the case of the Environmental Protection Agency’s regulations from 1986 onwards to have almost all lead removed from petrol. Just one problem: Needleman’s study was about as reliable as Michael Mann’s Hockey Stick.

In the Needleman affair, the McIntyre/McKitrick role was played by another academic child psychologist Dr Claire Ernhart, who worked in the same field as Needleman. She noted that Needleman’s research was based on serious methodological flaws. In particular, she claimed that he had not sufficiently allowed for “confounding variables” that might have explained the difference in IQ scores such as poor schools or parental neglect.

When an expert panel from the EPA tried looking into this, however, Needleman proved as reluctant to reveal the basis of his research as Mann did with raw data underpinning his Hockey Stick.

According to Booker/North:

“When in 1983 the panel visited Needleman’s laboratory to look at his data, he handed over six books of computer printouts, but said that only two panel members could examine them, and only for two hours.”

“Even during this cursory study, the panel found enough evidence to arouse profound doubts about Needleman’s research. Although starting with 3,329 children, he had winnowed out so many, often for apparently arbitrary reasons, that he had ended up basing his conclusions first on 270 subjects, then on just 158. ‘Exclusion of large numbers of eligible participants’ the panel concluded, ‘could have resulted in systematic bias’. In other words, it looked to the panel as though he might have selected his evidence to give the results he wanted.”

Lone bristlecone pines, anyone?

The expert panel concluded that Needleman’s studies “neither support nor refute the hypothesis that low or moderate levels of Pb (lead) exposure lead to cognitive or other behavioural impairments in children.” In other words, that his researches were valueless.

But hey, guess what happened then. Pressure was applied. The expert panel – for reasons which were never satisfactorily explained – completely reversed its decision. And the head of the EPA William Ruckelshaus (the same man responsible for the DDT ban which effectively condemned millions in the third world to die of malaria) was able to use Needleman’s study as the basis for doing what the EPA and environmental campaigners had been wanting to do anyway: ban lead from petrol.

Unsurprisingly, the EU soon eagerly followed suit. As even the Eu Commission admitted, the new rules would cost consumers an additional £4.8 billion a year, raise the average cost of a car by up to £600 a year and force oil companies into £70 billion-worth of new investment. Oh, and also, EU studies estimated, the switch to unleaded (it being less efficient than leaded) would also result in the creation of 15-17 million tonnes a year more greenhouse gas emissions.

But hey, as Michael Mann and his Team could surely tell us, when you’re trying to save the world from non-existent threat no price is too great to pay.