Thursday, May 26, 2005

Trying to bet on climate with Piers Corbyn

Piers Corbyn runs Weatheraction, an independent and rather controversial weather forecasting operation which claims to be able to make useful long-term predictions. It's controversial because most weather forecasters do not believe there is any merit in his principles (he claims that the forecasts are based on solar output) or his forecasts. Moreover, he refuses to detail his techniques or even test his skill in any objective manner. This article puts his case, and that of his critics, in a reasonably fair way. It seems likely that much of his "success", such as it is, is based on issuing forecasts that read like horoscopes, where an optimistic assessor would find merit, but a critical assessor would find fault. Anyway, I'm not really writing about his weather predictions, but his climate forecast.

On the 2nd February 2005, he gave this presentation to the Institute of Physics Energy Management Group. It contains the following:
In the next 5 or 10 years warming is likely to be maintained as a transpolar shift occurs. This will be followed by the magnetic pole moving away from the geographic pole, a decrease in solar activity, a southward shift in the Gulf stream and considerable world cooling by 2040 AD.
Of course this forecast strongly contradicts all the projections of the IPCC. If correct, it would have almost unlimited commercial value, as it implies (among other things) that all concern over anthropogenic global warming is misplaced. I think it's fair to say that the vast majority of scientists with any knowledge of climate science would say that the forecast is nonsense. However, what matters to me is what Corbyn himself thinks.

So, I emailed him to ask him if he could quantify his "considerable world cooling", and whether he would consider a bet with me on the subject. Note that unlike the other people I have previously tried to arrange bets with (here and here), he actually makes his living out of selling forecasts, and is proud to boast of taking on the bookies and winning. So he won't have the "I don't take risks" excuse of Myron Ebell.

I've not managed to get any reply out of him at all, still less a bet. For someone who claims a success rate of 80% or more with his forecasts, he seems remarkably reluctant to make any money out of this one. Could it be ... that he knows it is wrong?

So I'm still looking for that elusive consensus-busting sceptic who is prepared to make a forecast, and stand behind it. If anyone hears of a sceptical prediction, please let me know.


Brian said...

Great work James - please keep the offers going. I've written up the four prominent bets I've seen offered so far (and added one of my own):

Anonymous said...

Have you tried contacting Zbigniew Jaworowski? According to this article (see box on page 3) he claims that "a cooling of the climate has already commenced, and that a new cold phase will reach its climax in 20 years' time."

James Annan said...

Thanks for the comments - I have emailed Prof this space!

James Annan said...

Hi Piers,

Thanks for getting back to me. Due to the time zone difference, phoning the UK within your office hours is very inconvenient for me. But if your spam filter regularly throws away offers of 10,000UKP then perhaps you might find it worthwhile investing in a better one :-)

Really, I'm not as hostile as you seem to think. I certainly think that prediction skill should be judged on results, and if you can judge the odds reliably better than William Hill, then good luck to you. I know of the Dennis Wheeler paper, which was rather limited in scope. If you would be confident in a more comprehensive assesment, I'm sure that Pascal Mailier would be keen to include you in his forecast quality project, if you are not already involved.

But anyway, that is weather forecasting, and I am primarily interested in the longer term climate change, where I think your claims are badly mistaken.

Jim Giles said you were talking about paying up-front into an on-line betting service. Could you give any details? The obvious problem would be if the money did not accrue any interest - doubling my money in 20-30 years is probably no better than I could get at the bank with no risk at all. Since I am UK domiciled (although not currently resident), something like an index-linked gilt or FTSE tracker would probably be a sensible home for the money.

Anonymous said...

Corbyn's fundamental method is not original, but his back correlations probably are. The basic technique of predicting weather shifts from solar activity was discovered some years ago by Larry Berg.
Have a look at

Deano said...

So despite his huff and puff Corbyn didn't actually accept the bet then??

James Annan said...

That's right - "huff and puff" sums it up perfectly.


Anonymous said...

Piers Corbyn is right; what a jerk you are, James Annan, full of excuses. If you are based in Japan you can call UK any time after 18:00 local time and reach UK during office hours - I deal with a Tokyo based company and we speak almost every day. And millions of us get offers of £ 10 000 or more every day by email, usually from Nigeria, they just get dumped.
I don't know if Weather Action predictions are accurate or not, but I do know that Piers Corbyn has confirmed that he does place bets and you haven't made a serious attempt to follow it up. What a bluffer you are! (and a huffer and puffer yourself)

James Annan said...

Oh look, a drive-by anonymous troll. That's worth a serious response then...

But I'll waste a few more seconds of my time and point out that I'm not the only one who has tried to get something out of Corbyn on this and been met with obfuscation and evasion. If you think you can get him to agree to something concrete then be my guest, and perhaps you'll get back to me when you have something meaningful to report.

Edward Morgan said...

How thoroughly have you examined Piers work? Have you checked his forecasts? After all we make judgements from tangible stuff. I have and I if you read everything carefully he is getting what he says he is. This may appear to be not that accurate when you look at a forecast for a 3 day period but a general trend of the accuracy he is claiming is evident. So what actual reason have you to doubt his integrity?
Spend more time considering whether you have your facts straight before shooting at someone's character. I know you haven't done this, yet!! Cheers, Ed.

Frank Singleton said...

I would like to inject some cold logic into the discussions about Mr Corbyn and his ideas. As it stands, it is impossible to say whether or not Piers Corbyn has discovered a useful forecasting technique. To help people judge for themselves whether he may have done so, it should be noted that meteorology is rare, if not unique, among the sciences in that research workers and those engaged in forecasting liaise both nationally and internationally. There is and always has been a great sharing of scientific results, ideas and experience. This is through the literature, scientific meetings and the World Meteorological Organisation. WMO is one of those all too rare entities, a UN agency that actually works and works pretty well. This is because the science as a whole, and operational meteorology in particular, can only function with a high degree of international co-operation.
To the best of my knowledge, Mr Corbyn has never submitted his ideas for scrutiny by peer review. Had he written papers on his methods and discussed them in a scientific forum then he might carry some credence. As far as I am concerned, he does not meet that criterion. If he has discovered some new and important technique then he owes it to the world at large to share his knowledge for the benefit of mankind generally. Obviously, it is a matter of personal choice whether or not to pay for his services but those doing so might care to reflect on the above.
Noting Mr Corbyn’s letter to David Milliband and David King copied to his website, I can only refer him and others to . This is a web page on the Met Office website refuting some of the more ridiculous claims made in a Channel 4 programme that sought to cast doubts on the effect of man on climate change. It is written by the Met Office Chief Scientist, Dr John Mitchell. FRS. I know John from years ago and I can state unequivocally that he a scientist of high repute and integrity. He would not be FRS otherwise.
There are few, none that I know, reputable meteorologists working in the field of climate who do not concur with the report of the IPCC. There are some reputable scientists who do not concur, notably some well known through the media. However, none that I am aware of is a meteorologist or has any real knowledge of weather science. I, as a meteorologist, would not feel competent to comment on some new theory or ideas in biology or astronomy, for instance. It should also be noted that those that doubt climate change theories quite likely have some funding or support, directly or indirectly, from the oil industry. We are seeing a re-run of the opposition to the lung cancer and smoking connections discovered as long ago as the 1920s but only recently universally accepted by politicians and the general public. The vested interests in the industry consistently have distorted or funded distortion of the evidence.
Regarding sunspots and effects on the weather, yes, there have been statistical examinations of the connection. But, first, remember that there are lies, damn lies and statistics. I suspect that some of the tests chosen have been spurious. There are ways of filtering data that can show connections between sunspots and a series of random numbers. However, statistical techniques alone do not prove a connection. They may suggest one but it is always essential to study what the processes might be and to verify that the statistics are supported by the physics.
Neil Davis, gives a cogent argument for doubting that any connection between terrestrial weather and sunspots is at all likely. H W Norton writing in the US Monthly Weather review, see shows that there is no statistical evidence to support any connection between sunspots and weather.
According to the Guardian yesterday, Mr Corbyn is predicting temperatures down to ms 17 deg C in the Midlands within the next few days and a January in Britain with average temperatures around 0 deg C. Unless the report is incorrect, never trust the press, this will be an interesting test of his techniques.


James Annan said...


I basically agree with everything you've said. There is one paper, by Dennis Wheeler, which undertook a rather limited analysis of a single season and got some interesting results that seemed suggestive of some forecast at this point Corbyn effectively declared "victory" and has refused to co-operate in any further scientific investigation (which has been attempted by others).

I noted the -17C claim and have just blogged about some of his recent forecasts...

Frank Singleton said...

Thanks. I am not trying to pick a quarrel with Piers Corbyn. I am simply suggesting that he should tell us what he does and how. Meteorology has a history of old wives and old sailors who are supposed to know all about the weather. They know their own patch and the local variations. They can only see as far as the horizon. Their skill is limited accordingly.
Long range prediction is another matter altogether. Many approaches have been tried including statistical methods, analogue techniques, animal and bird behaviour, planetary, lunar and solar connections, studies of features such as El Nino and, of course, some forms of numerical weather prediction. The last two are the only ones that have an apparent physical basis.
If Piers Corbyn can demonstrate that his approach is a scientific one then he will be making a significant contribution to this very important subject. Unless he can do so he will not be taken seriously in the scientific community. From the magazine Weather, I understand that the Royal Meteorological Society is considering introducing a Kitemark scheme for weather services and products. That might induce Mr Corbyn to be more open than he has been so far.

James Annan said...

I agree with that. It would be great if he could demonstrate some method or analysis that improves on current science. But there are (presumably) enough people prepared to pay for horoscopes that there's no reason for him to want to cooperate (and a lot to lose if it went pear-shaped for him, which I strongly suspect it would). I understand that he refused to take part in this, which may be related to the kitemarking you mention.

Matthew said...

Why don't you assess Piers Corbyn's many successes?

Why concentrate on his relatively few failures?

I have been seeing his 45 day forecasts since January 2008 and they are about 70% accurate.

The met office can't do this in the same detail so why don't you pick on them for the mistakes they make only one day ahead?

This seems very biased.

James Annan said...


Interesting you should claim that Corbyn is "about 70 accurate" for the forecasts this year, cos I've been evaluating these same forecasts and find a 40% success rate (more recently here).

I'd be grateful if you could share your analysis, but somehow I expect you won't be back...

regular.guy said...

FRANK SINGLETON said: "Regarding sunspots and effects on the weather, yes, there have been statistical examinations of the connection. But, first, remember that there are lies, damn lies and statistics. I suspect that some of the tests chosen have been spurious. There are ways of filtering data that can show connections...."

This is a very true argument. However, if you look at the literature, you can see taht it also applies very well to the human-induced global warming advocates as well. Michael Mann et al published in the journal NATURE the now-famous 'hockey stick' graph that is so widely used by human-induced global warming advocates to support their cause. However, this graph was reexamined by McKitrick and McIntyre, and was proven to be a statistical artifact resulting from shoddy data compilation mehtods, inclusion of suspect low-quality data in the analysis, and incorrect use of the statistical technique of Principal Components Analysis (PCA). Their findings were supported by the editorial review board of the journal NATURE (the world's pre-eminent journal for sciences), and Dr.Mann was forced to print a partial 'corrigedum' retraction of his claims. As well, the US National Academy of Sciences Committee of Theoreticl and Applied Statistics (the best statisticians in the entire USA) also reviewed tboth analyses and decided that McKitrick and McIntyre (M+M) were right in saying Dr.Mann had produced garbage results and published them.

The results of M+M many published peer-reviewed scientific journal articles show that there was a warm period in medeival times and that the current temperatures of earth are NOT any warmer than they were back then. As well, further research by Canadian researchers looking at ice cores has found that temperatures in historiacl times (as far back as several 1000s of years) were observed to rise by as much as several degrees, with no effect from humans at all since this was before we had even discovered metal, let alone fossil fuels.

These papers I discuss here are currently published in peer-reviewed journals. Supreme sceptic who really want to find the articels and read them for themselves can look them up on Google Scholar, or in a university library. Stating that there is no peer-reviewed literature showing global warming in NOT caused by humans burning fossil fuels is completely wrong. There are in fact many articles that cover this exact topic in a thorough and scientifically defensible way. They appear to contain a much better quality of work than those of the human-induced global warming proponents, given the retraction that Dr. Mann had to print in the journal NATURE.

Good luck with your bets James, although I tend to think you will lose them if Piers has figured out some way to predict future solar activity and not just using past solar activity to predict short-term spurts of higher/lower solar intensity for his bets.

william said...

guess he must be affective to be banned form betting, the best thing would be to just bet against the met, winner takes all.

Jeff said...


Interesting post. Too bad that none of it is true. The findings of Mann, et al. were confirmed by the National Research Council and have been duplicated by numerous other reconstructions. And McKitrick and McIntyre have not publish "many" peer-reviewed papers.

Anonymous said...

According to the Weatheraction site, Piers has had papers on weather and climate prediction peer reviewed and published in journals. Don't know if you're suggesting this is incorrect? Also, his last 4 years of predictions for the summers and winters have been spot on, and the met office's predictions all wrong (all the met office predictions were warmer than how it turned out).
He also predicted the late-December snow (that we've just seen in the UK) back in July. The met office, conversely, said it was going to be one of the mildest winters on record and mentioned nothing of snow until days before.
From YouTubes that I've seen, Piers has stated that 2010 will continue the cooling trend we've seen over the past several years. The met office (surprisingly) are predicting 2010 to be one of the hottest years on record (again). It will be interesting to see who is right.

James Annan said...


No need to speculate, you can ask the all-seeing google how much he's published in his illustrious career. And the answer is....apparently less than a typical PhD student achieves by the time they graduate.

He has a habit of issuing vague horoscope-like forecasts and then painting the target round whichever bit happens to look most like reality. My analysis of his forecasts last year showed his success rate to be substantially lower than he claims.

Unknown said...

Mr Annan

1. I don't think that publishing an academic paper means a weather forecast is reliable or not. So I think you're barking up the wrong tree in trashing Corbyn's reputation due to his lack of publications.
2. The way Corbyn seems to issue forecasts is to start 6 - 10 months ahead of schedule with a certain confidence limit and then to either confirm with strengthened confidence 30 - 45 days out or to eliminate the forecast. If you trash this, you're probably trashing the tried and trusted method of many of the world's most successful financial traders.....who might, say, bet 2 at 1.9 and then either 8 at 1.2 on the same outcome or to close the bet out by betting 2 at as close as possible to 1.9 for the alternate scenario.
3. If Corbyn won £20,000 from William Hill, the key question is what annual return on his money did he make? If he turned £100 into £20000 in 14 years, I think PE firms might be interested. If he turned £10000 into £30000, maybe not.
4. The big question that you and he may need to face is this:
'is extreme weather forecasting 10 months ahead an appropriate basis for 30 year predictions on general global climate?'

Now that IS where I think an understanding of his method would be necessary.

Thing is, he's running a business, he's not an academic funded by the taxpayer.

And anyone who's running a knowledge-based business doesn't open their box of tricks to the public, because then their USP becomes a commodity.

So it may be unreasonable to expect him to expose all.

By the way, the key parameter in deciding whether the world is warming or cooling is where you take the readings, how you take them and how you calculate an index.

Until people agree on that, you may be all barking up the wrong tree.


James Annan said...


Thanks for posting a sane comment. However, it is only through documentable results that Corbyn's claims can be validated, and these are in short supply (to put it politely).

As for revising forecasts, there is no problem issuing updated forecasts at a shorter lead time but in any assessment of forecast skill at a particular lead time, it is essential to include all the forecasts issued with this lead time, not quietly forget the ones that turned out to be wrong!

Turning your presumptions around, if Corbyn was a con-man pure and simple, how do you think his actions would differ from his observable behaviour?

It would be trivial to arrange scientifically valid tests of his forecasts, in fact I know that people have asked him to take part in such trials, and he has steadfastly refused. IMO it is hard to avoid drawing the obvious conclusions...

Jim said...

I'm farmer in the UK. I need accurate weather forecasts, especially in the summer, for haymaking. For the last 3 years I have followed the UK Met Office 5 day forecast religiously. It is ALWAYS wrong beyond 3 days. They constantly forecast heavy rain, and then reduce it as the day in question approaches.

I am going to give Piers Corbyn's forcasts a go this summer. They can't be worse than the Met Office, which takes my tax money and gives me cr@p in return.I have compared his 2009 July & August 30 day forecasts with my diary, and note that he predicted both a predominantly wet July (it was) and also the one dry spell of weather we had in August (around the middle of the month). This would have been very useful to me, making hay.

All I can say is this - he charges for his forecasts, and is still in business after 15 years. If people are prepared to part with cash for his advice, and keep paying, it can't be that inaccurate, can it? Money talks.

Unknown said...

Well, it's nearly 6 years on now. Is Piers still wrong...?

citizenschallenge said...

Well Jay, the ice age still hasn't appeared.