McLean – Hot Topic

Saturday snark: a textbook for Vincent

As Stoat points out, the IPCC has released the reviewers comments on the Working Group One second order draft report. And as you might expect, the IPCC’s favourite inexpert commenter, the New Zealand Climate “Science” Coalition’s very own Vincent Gray was busy reviewing their work. Here’s comment 1-549 from Chapter One (pdf) by Gray:

The records shown are not “observations” and they are not “temperatures”. They are also not “globally averaged. They are a set of multiple averages, subtracted from an overall average, compiled from a vaying non-standardised set of maximum an minimum temperature measurements at varying weather sations and ship measurements. They were previously treated as “Mean Global Temperature anomaly” The uncertainties attached to each figure are very great, individual temperature measurements are rarely accurate to better than one degree, so a claimed “trend” over 100 years of less than one degree has a very low level of statistical significance. [Vincent Gray, New Zealand] (all spelling from IPCC doc)

The response from the editors is a minor classic of its kind:

Rejected – The comment does not reflect the scientific understanding. The errors in individual observations are not additive; we are also doing relative analysis that eliminates many of the concerns about individual errors. The reviewer obviously has a limited understanding of the associated error evaluation for analysis of large datasets. See Chapter 2 for more on the evaluation of these datasets. Or maybe even read a basic textbook. (my emphasis)

For more on accuracy versus precision, and the statistical power of large numbers, this classic post by Tamino is well worth a read.

There are other minor gems to be found as the reviewers deal with Monckton (in the “general” section) and John McLean (seemingly everywhere). In fact McLean’s ubiquity suggests that he may have acceded to Gray’s throne as the man with most comments on a single IPCC report. But don’t expect me to add them all up, I do have a life…

NZ Herald’s turn to offer propaganda as opinion – De Freitas’ links to cranks hidden from readers

The new “compact” NZ Herald has taken a downmarket tabloid approach to informing its readers by running an opinion piece about the recent courtroom defeat for NZ’s climate cranks by prominent climate sceptic and Auckland University geographer Chris de Freitas, without explaining de Freitas’ long history of association with the cranks he’s defending. In the article, de Freitas overstates the uncertainties associated with temperature records, even going so far as to imply that the warming trend over the last hundred years might be “indistinguishable from zero”¹. He also overplays the importance of temperature series to policy-makers — a line straight out of crank litigant Barry Brill’s playbook, and self-evident nonsense.

Despite this transparent partiality, the opinion editors at the Herald credit him like this:

Chris de Freitas is an associate professor in the School of Environment at the University of Auckland.

But, as the Herald opinion team well know, de Freitas is much, much more than a mere associate professor in the School of Environment. He has a track record of activism against action on climate change that stretches back two decades. Here, for the poor misled readers of the new Herald‘s opinion pages is a handy, cut-out-and-keep guide to de Freitas’ long history of climate denial activism.

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“Temperature trends detected are small, usually just a few tenths of one degree Celsius over 100 years, a rate that is exceeded by the data’s standard error. Statistically this means the trend is indistinguishable from zero.” [↩]

McLean’s folly 2: the reckoning

Ten months ago, Aussie “sceptic” John McLean predicted that 2011 would be “the coolest year since 1956”. I pointed out at the time that this was nonsense, and so it has proven to be. I’ve taken the GISS global temperature figure for Jan – Nov 2011 (+0.51ºC compared to the 1951-80 average) and added it to the graph I created to illustrate the full extent of McLean’s folly:

Maclean1956outcome

Last year was warmer than 1956 by a whopping 0.68ºC — about three standard deviations, in statistical terms — making McLean’s forecast an abysmal failure. Yes, 2011 was cooler than 2010 or 2009, but still one of the top ten warm years.

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Predicting the bleeding obvious (and getting it wrong)

A couple of days ago one of the leading figures in the New Zealand climate crank pantheon, the Climate “Science” Coalition’s very own Bryan Leyland, popped in to Hot Topic and left a comment drawing attention to his new favourite game — “predicting” global temperatures by projecting the southern oscillation index forward seven months. He bases this on the “work” of John McLean, last mentioned here a couple of months ago when I looked at his prediction (happily promoted by the NZ C”S”C) that 2011 will be the “coolest year globally since 1956 or even earlier”. Suffice to say, it won’t be.

Leyland first notes the infamous McLean, De Freitas and Carter paper of 2009, then his own “prediction” that this year’s La Niña would bring a cooling in global temperatures, and then says:

What is remarkable about this is that a retired engineer with access to the Internet has been able to make accurate predictions of future climate. Yet, to my knowledge, no computer-based climate model nor any mainstream “climate scientist” predicted this cooling. To me, this is truly remarkable.

What’s really remarkable is that Leyland is actually only showing his ignorance of some pretty basic climate relationships.

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McLean’s folly and the climate clueless

In an astonishing press release issued last week, the New Zealand Climate “Science” Coalition predicts that 2011 will be the “coolest year globally since 1956 or even earlier”. The C”S”C bases its prediction on the work of Australian “computer consultant and occasional travel photographer” John McLean. Hot Topic readers will remember McLean as the lead author of a rapidly rebutted 2009 paper (written with Chris de Freitas and Bob Carter) which claimed that El Niño/Southern Oscillation (ENSO) events were a driver of global temperature increases. I covered the full story at the time: see Mother Nature’s Sons and subsequent posts.

One unoriginal finding of the McLean paper was that global temperatures were affected by ENSO events — warming after El Niños and cooling after La Niñas. Last year NZ C”S”C member Bryan Leyland used this to “predict” a coming cooling, which was lapped up by the usual suspects. In January this year, Leyland predicted cooling would continue until at least June. Now McLean has taken this a step further by predicting that temperatures will plunge to that of a cool year 50 years ago. There’s no justification for this prediction in the press release, beyond McLean pretending that his 2009 paper showed that CO₂ was a minor player in global temperature change.

Unfortunately for the credibility of all involved, McLean’s prediction is utter unphysical nonsense. Here’s why…

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