Archive for March, 2010

Lindzen and “No statistically significant warming since 1995”

March 3rd, 2010 51 comments

I discussed the ‘no statistically significant warming since 1995’ talking point in this post. For those who came in late, this talking point has been around the delusionist blogosphere for some time, though with a lower profile than ‘global warming stopped in 1998’, and was put as question to Phil Jones of UEA in a BBC interview. Jones answered honestly, if a bit clumsily, that the data period since 1995 is marginally too short to derive a statistically significant trend, a response which was headlined by the Daily Mail as “Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995?” and became the talking point of the day. As has been widely noted, confusing not statistically significant’ with ‘not significant; in the ordinary sense indicates either deliberate dishonesty or ignorance of a point covered in excruciating detail in every introductory stats course.

But where did this silliness come from? I’d seen Janet Albrechtsen quote Lord Monckton on the point, and it seemed about right for him, an innumerate debating point that would take a fair while to refute, during which time he could move on to the next one.

Imagine my surprise, then, when I discovered the point being made (and apparently originated) by Richard Lindzen of MIT who is (or ought to be) by far the most credible figure on the delusionist side. In a piece published on “Watts Up With That” Lindzen says ‘There has been no warming since 1997 and no statistically significant warming since 1995’ and in this piece for Quadrant he gives a variation, saying “has been no statistically significant net global warming for the last fourteen years” and “the fact that warming has ceased for the past fourteen years is acknowledged” . Note the slide from “has been no statistically significant net global warming for the last fourteen years ” to “warming has ceased”, committing the basic newbie error against which all budding stats students are warned.

Lindzen has published a couple of hundred papers in climatology, so I think we can assume he knows that the statement “there has been no statistically significant warming since 1995” means nothing more than “given the variability in the data, we need at least 15 observations to reject the null hypothesis at 95 per cent confidence”, a fact so trite as not to be worth mentioning.

It is sad to see a respected scientist reduced to this kind of thing. And as far as I can tell, all this is simply to avoid admitting that he backed the wrong horse back in 1990, when he bet that he was smarter than the majority of climate scientists who thought humans were (probably) causing global warming. The data since then has supported the majority view, but instead of revising his position, Lindzen has resorted to dishonest statistical trickery.

To quote The Economist, with respect to the Daily Mail

Since I’ve advocated a more explicit use of the word “lie”, I’ll go ahead and follow my own advice: that Daily Mail headline is a lie.

But at least the Daily Mail headline writer could plead ignorance. Lindzen has no such excuse.

Update: More on this from Deep Climate

Categories: Environment Tags:

Sockpuppet attack

March 1st, 2010 20 comments

I’ve just edited several comments from sockpuppets ‘Julia’ and ‘Colin’ posting Liberal Party talking points. Both posted using IP, then ‘Julia’ switched to another one, also in the range Spurious email addresses [email protected] and [email protected] Anothe commenter advises ‘Julia’ has been seen at LP.

If anyone can out these pests, I’ll happily publicise the results.

Categories: Metablogging Tags:

Four lies and an empty set

March 1st, 2010 119 comments

The switch from ‘scepticism’ to an overtly anti-science, and anti-scientist, position has paid some dividends for the advocates of delusional views on climate change. Although the only wrongdoing in the CRU harassment/hacking campaign was that of the hackers and their allies (more on this soon), the false charges of scientific fraud got much more media attention than their refutation, and the early responses to alleged FOI breaches (including that of some pro-science writers such as George Monbiot) failed to recognise of the deliberately vexatious misuse of FOI by the anti-science group. In this context, the discovery of a genuine error in the 1700 page IPCC Fourth Assessment Report regarding projected changes in glaciers could easily be spun into something much bigger.

It seemed for a little while as if the delusionists had scored another win, when Phil Jones, the scientist who has been most viciously target by the hackers/harassers gave an honest answer to a deliberately loaded question prepared by them and put to him in a BBC interview

BBC: Do you agree that from 1995 to the present there has been no statistically-significant global warming?

Phil Jones: Yes, but only just. I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods…

This was headlined by the Daily Mail as “Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995?.

But, now it looks as if this is starting to backfire. Anyone who has successfully completed a basic course in statistics knows that “statistically significant” has a special meaning which bears almost no relationship to the usual sense of the term “significant”, and this fact is beginning to sink in.

Read more…

Categories: Boneheaded stupidity, Environment Tags:

Monday Message Board

March 1st, 2010 61 comments

It’s time, once again for the Monday Message Board. Post comments on any topic. As usual, civilised discussion and no coarse language.

Categories: Regular Features Tags: