GW denier Phil Jones has conclusively demonstrated that up is actually down.

[wtmusic]

"BBC: Do you agree that from 1995 to the present there has been no statistically-significant global warming?
Phil Jones: Yes, but only just."

Despite the lame arguments below by Australian climatologist Barry Brook to the contrary, I have to admit - it doesn't get much plainer than this:



http://bravenewclimate.com/2011/01/02/no-statistical-warming-since-1995-wrong/

[joshcryer]

1. Woot, Barry Brook is posting again. Win post, at that. :D

[muriel_volestrangler]

2. What's your point?

Jones, who is no denier, as I'm sure you know, was giving the exact answer about statistical significance, that is the normally-accepted statistical definition. He was not saying that 'no increase' is as good a fit as 'an upward trend', so Brook's "the model that says there IS a trend in the data is 1.44 times better supported by the data than the model that says there isn’t" in no way contradicts what Jones said. And, as Brook says, when you add in the 2010 data which came after Jones answered the question (which had been sent in, almost certainly, by a sceptic who cherry-picked the length of the period to avoid statistical significance), the data now fall into the realm of 'a statistically significant upward trend'.

[wtmusic]

3. In any other context it would be a tempest in a teapot

but for Jones to not at least acknowledge any alternative methods of analyzing the data adds fuel to the skeptic fire. I'm no expert at statistics, but Barry Brooks' point seems to be that classical evaluations of significance are simplistic and mostly useless for drawing any kind of conclusion from data as limited and noisy as this is.

IMO it's a valid point.

[jpak]

4. Cherry picking data is not a valid point IMO - you can cherry pick any interval of noise

in the recent climate record and stupidly claim "global cooling".

The Earth is clearly warming and no one but a fool can claim otherwise.

yup

[joshcryer]

8. Yes, but as Barry points out, the cherry picked number in the question posed to Jones is in fact...

...statistically significant.

[muriel_volestrangler]

5. For Jones to suddenly change his standards at that point would have been worse

It would have made him look like a politician, not a scientist, if he had said "well, I'll ignore the widely-accepted standards I and my colleagues have used up until now, and move to the opinion of some statisticians because that'll enable me to answer 'no' to your question". It would have made him look exactly like the dishonest person the deniers were trying to paint him as, at the time. As it was, he stuck to his science and statistical standards, and all reports exonerated him.

That's a much better result, and he doesn't deserve to be labelled a 'denier' by you. The only decision that might be criticised is whether he should have agreed to answer questions submitted by the public in the first place, because there'd be a good chance some deniers would get their cherry-picked questions in. His full answer does a fair amount of explaining, but some people, of whom 'spangled drongo' seems to be one, love to quote it without the explanation.

[wtmusic]

6. I didn't remember him as the East Anglia researcher

and you're right - the "denier" label is unfair.

That said, he wouldn't have to change his opinion at all but merely emphasize that statistical significance is pretty worthless given a limited data set. As someone who has a rep for being impolitic in the past, he should know to beware of loaded words like "significant", which has a generic connotation quite different than the scientific one.

[muriel_volestrangler]

7. Which he mor or less did in his full answer

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

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.

C - Do you agree that from January 2002 to the present there has been statistically significant global cooling?

No. This period is even shorter than 1995-2009. The trend this time is negative (-0.12C per decade), but this trend is not statistically significant.

http://news.bbc.co.uk/1/hi/8511670.stm

But he can't prevent his quote being cut short.

[joshcryer]

9. Yes, edit out the "denier" part of the topic if you can.

It's not right and feeds into the myth that Jones doesn't believe in climate change.