Climate bet

I wasn’t aware that Scott Armstrong – one of the guru’s of forecasting – and Al Gore almost had a bet. The bet goes something like this:

In 2007, University of Pennsylvania Professor J. Scott Armstrong’s attention was drawn to former VP Gore’s concerns about global warming. Having spent five decades studying the science of forecasting, Armstrong decided to examine the basis for the forecasts of global warming. He was unable to find a single scientific forecast to support the claim that the Earth was becoming dangerously warmer or colder.

Instead, he found that some scientists were using improper forecasting methods to make forecasts. Professor Armstrong alerted Mr. Gore to this fact and suggested that they cooperate in a validation test of dangerous global warming forecasts. He suggested a 10-year bet for which he would forecast no long-term trend in climate, while Mr. Gore could chose forecasts from any climate model.

Before anyone gets too excited let’s unpack a couple of those terms, especially “scientific forecast” and “improper forecasting methods”. Kesten Green and Scott Armstrong have a paper that evaluates the IPCC forecasts against 140 accepted principles of forecasting and the IPCC methodology comes up short.

To provide forecasts of climate change that are useful for policy-making, one would need to forecast (1) global temperature, (2) the effects of any temperature changes, (3) the effects of alternative policies, and (4) whether the best policy would be successfully implemented. Proper forecasts of all four are necessary for rational policy making.

The IPCC Report was regarded as providing the most credible long-term forecasts of global average temperatures by 31 of the 51 scientists and others involved in forecasting climate change who responded to our survey. We found no references to the primary sources of information on forecasting methods despite the fact these are easily available in books, articles, and websites. In our audit of Chapter 8 of the IPCC’s WG1 Report, we found enough information to make judgments on 89 out of a total of 140 forecasting principles. The forecasting procedures that were described violated 72 principles. Many of the violations were, by themselves, critical.

I have seen Kesten Green present this paper and given what we now know about the IPCC it doesn’t surprise me. But this part of the argument, I think, is weak. The argument here falls into an area where the opinions of Green-Armstrong conflict with the opinions of the IPCC forecasters and the area where the art and science of forecasting overlap. I’m not saying Green-Armstrong are wrong just that I’m not entirely convinced that it is correct. But this is the basis for the terms “improper forecasting methods” and not a single “scientific forecast”. Okay – the next bit is much more interesting.

Kesten Green, Scott Armstrong and Willie Soon published a paper that set out a “no-change” benchmark forecast of global temperatures. I have seen Kesten Green present this paper too – it is much more convincing than the previous paper.

Global mean temperatures have been remarkably stable over policy-relevant horizons. The benchmark forecast is that the global mean temperature for each year for the rest of this century will be within 0.5C of the 2008 ?gure.

There is little room for improving the accuracy of forecasts from our benchmark model. In fact, it is questionable whether practical bene?ts could be gained by obtaining perfect forecasts. While the Hadley temperature data in Fig. 2 drifts upwards over the last century or so, the longer series in Fig. 1 shows that such trends can occur naturally over long periods before reversing. Moreover, there is some concern that the upward trend observed over the last century and half might be at least in part an artifact of measurement errors rather than a genuine global warming (McKitrick & Michaels, 2007). Even if one accepts the Hadley data as a fair representation of temperature history, our analysis shows that errors from the benchmark forecasts would have been so small that decision makers who had assumed that temperatures would not change would have had no reason for regret.

So that paper forms the basis for the proposed bet. Indeed the paper discusses the famous Julian Simon – Paul Ehrlich bet. As it turns out Al Gore did not accept the bet.

Nonetheless the question arises, how would the bet be going?

Of the first 60 months of the 120 month (10 year) Climate Bet, Scott Armstrong’s naive model forecast* of no change in global average temperatures has been closer to the actual temperature than Al Gore’s IPCC-orignated 3°C per century warming forecast for 40 months.

Original here.

Scott Armstrong is confident of winning.

When he proposed the bet, Professor Armstrong expected to have a somewhat less than 70% chance of winning given the natural variation in global mean temperatures for a ten-year period. In light of the results to date, he expects an even better chance of winning, but as Yogi Berra said, “It’s not over till it’s over.”

Something to watch with interest.

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34 Responses to Climate bet

  1. Token

    How long before the usual AGW cultists come forward to make personal attacks Scott Armstrong instead of addressing the science?

  2. Rafe

    Great stuff, I was going to post that but went out for breakfast instead.

    Anther piece from the same source, the European carbon market still going down.

  3. Jim Rose


    Ehrlich and others including John Holdren, later an advisor to Obama for Science and Technology picked five metals

    I did not of Holdren’s role is the wages until I just checked the wiki.

    at lest he put his monye were his mouth was. did he pay up?

  4. mundi

    Ehrlich doesn’t get it. The earth can’t loose mass, and it continually gets energy. Therefore there is no way we can run out of resources (until billions of years when the sun dies). The metal themselves were a poor way to make the bet. Even if you take food (which Ehrlich preferred) he was even more wrong, and the fact that he still blabs on about food means he learnt nothing despite losing the bet.

    This is of course the root of why the green movement is doomed to fail. Greens live as if the atoms that make up fresh water disappear when we consume them. They have no concept that only energy matters and that we have an absolute abundance of energy from coal (thousands of years) and the sun (billions of years), just to name two sources.

  5. Bruce of Newcastle

    With four parameters I can fit an elephant, and with five I can make him wiggle his trunk.

    – John von Neumann

    I’ve seen this with my own eyes when formulating models in my own field – it is relatively easy to fit a multiple regression model to a dataset, in this case global temperature during the 20th C.

    The challenge for modellers though is to find the right parameters. Only then will the model be useful.

    Our colleagues in the IPCC modelling fraternity have been frantically trying to fit CO2 as the main variable causing temperature rise to the recent record. They first said it must be a hiatus. Then they said it was aerosols from Chinese coal burning. Now they are questioning the effect of black carbon.

    But what this says is they are chasing moonbeams trying to smooge their ‘CO2 is important’ modelling strategy into the validation dataset. It just doesn’t fit. Which is why UK Met Office, who has now included a larger forcing from the PDO and AMO cycles finds that the resulting model becomes flat for the next 4 years – as Scott Armstrong bet.

    Eventually climate modellers will be forced to acknowledge the real significant variables, which are (1) solar overall forcing and (2) ocean cycles followed then, possibly, by CO2 as the third most significant variable. Only thence will the models have predictive skill.

    I was struck by this comment when I read a post this morning:

    Moreover, Lüning’s and Vahrenholt’s temperature model for the next 100 years so far has been dead on.

    Not everyone’s model has the wrong significant variables.

  6. The greens are fond of saying Earth is a closed system, ignoring that bright thing in the sky called “The Sun”.

    That said, resources are not infinite, as that implies infinite energy from the sun. Still, our potential energy equals all energy received from the sun plus energy and resources “banked” in the earth and its atmosphere. This also includes abiotic oil, whose existence is of course unproven and production rate unknown.

  7. Rodney

    I wouldn’t have a bet with Al Gore. The Sovreign Risk is too great.

  8. WhaleHunt Fun

    It has bet your financial future on the global community agreeing all to massively reduce the use of cheap carbon based energy sources.
    Now we see that the predictions that are the reason to expect the nations of the world to do this are not at all well based.
    While its boosters whine about the word witch, many would never attach anything so lacking in insult to it. They justifiably would wish words of near-infinitely greater vitriol.

  9. cohenite

    The wager uses UAH which is running a bit hotter than RSS.

    Gore’s position is 0.3C perdecade or 0.003C per year.

    UAH is 0.0130573 per year and RSS 0.00673124 per year.

    Both are less than Gore but more than Armstrong.

  10. eb

    Sheesh cohenite, your calculator must be on the blink; 0.3C per decade is 0.03C per year.

  11. Kaboom

    Unfortunately, as we are all aware, Armstrongs cheat.

  12. manalive

    … the IPCC modelling fraternity have been frantically trying to fit CO2 as the main variable causing temperature rise to the recent record. They first said it must be a hiatus. Then they said it was aerosols from Chinese coal burning. Now they are questioning the effect of black carbon …

    I can’t help thinking of epicycles on epicycles.

  13. hammygar

    Here’s an interesting article on Climate Change. I’ll back this fellow versus you any day, Sinc.

  14. Kaboom

    In particular, Armstrongs cheat on epicycles.

  15. cohenite

    Thanks eb; I had tried to post before but it got lost. The point stands.

    There is another alternative; temps fall. Depends on the sun because CO2, especially human CO2, doesn’t appear to be doing the job.

  16. John Mc

    Harry Clarke is a lightweight wuss. Both intellectually and in every other way. He used to hang around here until he realised he couldn’t hold his own.

  17. cohenite

    Anyway, the IPCC and its models cannot even HINDCAST.

    Why is why all the adjsutments to past temps are occurring; if the theory doesn’t fit the data, change the data.

  18. Johno

    Is that really the bet you can do hammy. Lift your game.

    [Slight edit. Sinc]

  19. JC


    Ummm Harry has so far backed
    1. Painting all roofs white to reflect back the light

    2. Taken seriously a 200 year clmate change forecast and advocated policies in that stupid paper.
    3. Worried about cow farts and promoted eating more Kangaroo which are supposed to fart less.

    4. Reduce population in any way possible including aggressive forms of birth control.

    5. He of course has no problem travelng on planes himself

    6 voted or suggested he would vote green

    Kero stop the trolling as you’re no composta.

  20. blogstrop

    OK, we’ve had Professor Hammyga-ga’s nomination (fail); stand by for Steve Q.C., PH.D, from Brisbane.

  21. jumpnmcar

    There is a punt if anyone is interested.
    Pays out in mid 2033.

  22. Pingback: Climate change stopped 16 years ago « Harry Clarke

  23. jumpnmcar

    Lindzen was a bit of a chicken in 2005.
    Wonder if he’s a little more courageous in 2013?
    I would think so.

  24. Kaboom

    According to Harry Clarke, “The contributors at this sight have a casual regard for truth.”

    The idiot is talking about the Cat.

    Complete hyperbowl. How about a debate, you doofus?

  25. chrisl

    Poor Harry has has spelling issues … site not sight
    And he bans anybody who disagrees with him…
    You just have to wonder if these people live in such a bubble that they can’t countenance any other argument.

  26. Grey

    Since Gore is only backing a 0.3 rise over the decade and the intra-5 year gap is already 0.8 between the min and max, how the graph looks will depend on whether you start or finish on a hot or cold year.

    For example if the period had begun in 2008 Gore would be looking good, and if 2013 turns out to be a hotter year he still won’t look bad.
    But because 2007 was a local maximum, a possible trend has been obscured temporarily – but in the long run it will be apparent.

  27. Gab

    I’ll back this fellow versus you any day, Sinc.

    Praise the gaia! I’d be mighty concerned for Sinclair if you backed him.

  28. Steve of Glasshouse

    Hammy is training to be a fluffer for Gore et al

  29. Sinclair Davidson

    Grey – the issue is that we’re not quite sure what the terms of the bet were. An unusually hot or cold year could deliver the bet either way. That wouldn’t provide any information.

    I’m rather surprised at HC’s hysterical response at his blog to what is a straight down the line blog post containing factual information and analysis.

    Should point out that Scott Armstrong and his critique are mainstream – Nate Silver discusses it in his recent book. In the end Silver reckons the Armstrong critique (about scientific method) is weak – so do I and told that to Kesten Green when I first saw the paper.

    Anyway, this isn’t an invitation to launch into Harry – he is a good guy but has this particular obsession.

  30. braddles

    For the record, there was no bet. It was offered, but Gore turned it down.

  31. Sinclair Davidson

    For the record, there was no bet.

    Yes – first sentence of the post

    Scott Armstrong … and Al Gore almost had a bet.

    The later:

    As it turns out Al Gore did not accept the bet.

  32. Leigh Lowe

    Unfortunately, as we are all aware, Armstrongs cheat

    Neil’s moon landing was filmed on location in New Mexico.
    Lance has ingested more gear than Keef Richard and River Phoenix combined.
    Louis mimed most of the shit he recorded.
    Kerry Armstrong calling herself an actor? ……. ’nuff said.
    But Scotty seem to be the exception that proves the rule.

  33. Helen Armstrong

    Continuing on the Global Warming and pollution carbon dioxide theme, along with Europes fabulous carbon di-oxide mitigation – green power everywhere, Donna has this report form da speigal. Europeans are stealing wood to burn wood for warmth as the cost of power escalates.

    Greeks are chopping trees down in parks – how’s that greenies? Wood stoves have a resurgence in popularity and old people are three times more likely to die in cold as in hot.

  34. AndrewL

    I wasn’t aware that Scott Armstrong – one of the guru’s of forecasting – and Al Gore almost had a bet.

    Almost had a bet? In that it was offered and the Gore declined to propose a position?
    Armstrong misrepresents the IPCC position in claiming a forecast of 0.3 degrees C per decade. The AR 4 2007 multi-model projection was 0.018 degrees C.

    Armstrong also fudges by claiming UAH adjustments improve his side of the bet when they didn’t change the trend, only the baseline for the anomaly. Either he is scientifically ignorant or dishonest. Given he “lost” the password of the site while the El Nino of 2010 was smashing his side of the “bet” I have a fair idea of where my money sits.

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