Another big climate bet — Of Ice and Men

arctic iceGood news: I got three guys to put up a total of $1000 against the bet in my recent post, “Ice Ice Maybe (not)”:

It is very safe to say the Arctic Sea will be essentially ice free by 2030, and I’d personally bet on 2020 — any takers?

Not so good news: The “takers” are not global warming doubters, quite the reverse — they are three well-known and knowledgeable climate bloggers — James Annan, William Connolley, and Brian Schmidt — and James and William are certifiable climate experts.

That said, I think I’m going to win this, as I’ll explain. I estimate the odds at at least 2 to 1 in my favor — no this isn’t the same kind of 100-to-1 lock the hydrogen bet is — though James, William, and Brian have, unintentionally, given me (slightly) better than even odds. Let’s start with the bet:

At no time between now and the end of the year 2020 will the minimum total Arctic Sea ice extent be less than 10% of the 1979-2000 average minimum annual Arctic Sea ice extent, as measured by NSIDC data or any other measurement mutually agreed-upon; provided, however, that if two or more volcanic eruptions with the energy level equal to or greater than the 1991 Mount Pinatubo shall occur between now and the end of 2020, then all bets are voided.

The 10% minimum covers me against straggling ice. I also asked for the two-Pinatubo voiding — I didn’t want to lose this bet if warming is temporarily slowed by an unusual series of big volcanoes.

Why will I win?

Before answering, let me note that Brian blogs he is “betting against over-alarmism.” Annan says, “I think it is unreasonable to claim that all the models and research (which suggests ice-free around mid-century and perhaps later) is badly wrong.” Let’s see why they are probably wrong, like all the models (but not all the research).

First, my side of the bet does not appear to be a bad one if recent trends merely remain relatively linear. The commenters on William’s blog (crandles and Gareth) do the math if you’re interested.

But if you’ve been reading Climate Progress, or my book, then you know, to paraphrase Dorothy, “I’ve a feeling we’re not in linearity anymore.” That was the point of my posts: Are Scientists Overestimating — or Underestimating — Climate Change (Part I and Part II and Part III). And Arctic ice is probably the most nonlinear thing going.

Indeed, in Part I, I quote from a talk I attended by a top Norwegian expert (PDF of his PPT here): “The recent [Arctic] sea-ice retreat is larger than in any of the (19) IPCC [climate] models.” And that was 2005!

In an American Meteorological Society seminar, Dr. Wieslaw Maslowski of the Oceanography Department at the Naval Postgraduate School reported that models suggest the Arctic lost one third of its ice volume from 1997 to 2002. He then made an alarming forecast:

If this trend persists for another 10 years–and it has through 2005–we could be ice free in the summer.”

And again, that was in 2006, so he was talking about being ice free in 2016! And everyone tells me he is no alarmist.

Of course, in 2007, as one of the normally staid National Snow and Ice Data Center experts, Mark Serreze, said in early September, “It’s amazing. It’s simply fallen off a cliff and we’re still losing ice.” Serreze said a couple of years ago he believed the models that predicted an ice-free Arctic in “2100, or 2070 maybe. But now I think that 2030 is a reasonable estimate.”

By late September, the Arctic had lost “an area approximately equal to the size of Alaska and Texas combined” compared to its “long-term average minimum, based on averaging data from 1979 to 2000.” You can hear Serreze’s latest thoughts, along with other equally alarmed experts, at this recent AMS seminar. (Note that in his talk Konrad Steffen points out that the ice/water shift is very non-linear in the sense that the temperature over thick ice can get very, very cold, but over thin ice or water, it is near freezing — meaning there is the ability to release huge heat, especially in the fall — which is relevant to the figure below).

In an October 1 press release, the NSIDC makes clear that thinning ice creates a kind of feedback of its own:

One factor that contributed to this fall’s extreme decline was that the ice was entering the melt season in an already weakened state. NSIDC Research Scientist Julienne Stroeve said, “The spring of 2007 started out with less ice than normal, as well as thinner ice. Thinner ice takes less energy to melt than thicker ice, so the stage was set for low levels of sea ice this summer.”

The other reason I made this bet is a Science magazine article I blogged on this summer predicting an accelerated warming over the next several years. Their research suggests “at least half of the years after 2009 [are] predicted to exceed the warmest year currently on record“:

They further predict the year 2014 will “be 0.30° ± 0.2°C warmer than the observed value for 2004,” which means there is a 50% chance that the warming from 2004 to 2014 will be 3/8 that of the warming of the previous century!

So yes, I expect to win the bet. And since I can theoretically win $1000 well before 2020, but can’t lose $1000 until 2020, I’m getting a (very) little better than even odds.

And in case you were wondering how the rethickening of the ice might be going now in late fall, here’s a stunning plot of the global temperature anomaly as of Tuesday (click to enlarge):


Yes, large parts of the Arctic are 15 to 20°C (!) warmer than normal! (Tip o’ th’ hat to Gareth.) This is what we expect as larger and larger swaths of the Arctic are ice free or only thinly covered with ice in the fall.

So are all the models wrong? As the old saying goes, “The best laid schemes of ice and men….


31 Responses to Another big climate bet — Of Ice and Men

  1. Paul K says:

    It is very reassuring that top climate scientists do not share your apocalyptic premonitions.

  2. “And since I can theoretically win $1000 well before 2020, but can’t lose $1000 until 2020, I’m getting a (very) little better than even odds.”

    I thought of that too, but only after we settled the bet. Oh well. The even odds could’ve been restored by requiring you to wait until 2021 to collect, but that’s silly (and not part of the agreed-upon bet).

    I’m just glad to be on the side of the bet where I hope to win this time, instead of hoping to lose.

    I’d agree with the suggestion that the next two years will give a good indication as to who’s likely to win.

  3. Joe says:

    I didn’t think of it before either.
    It is impossible to figure out what I gain — since we don’t and can’t have a probability function of my winning or losing.

    Paul K:
    Interesting you call the Arctic being ice-free “apocalyptic” — because I think it is safe to say that all three of those experts expect the Arctic to go ice free this century if we don’t reverse emissions trends very soon.

    I think it would be quite bad, but I haven’t decided whether it would be apocalyptic like, say, losing Greenland (which, I concede, losing the Arctic ice would make far more likely).

  4. Ron says:

    Joe, James, William, and Brian,

    Can you give me odds on the ice being back to near normal within the next two years?

  5. Paul K says:

    At the risk of paying climate scientists compliments twice in one day, here is news from the National Science Foundation website: The new CCSM-2 climate model developed at the National Center for Atmospheric Research (NCAR) is expected to play an integral role in the next climate assessment by the Intergovernmental Panel on Climate Change. I do wonder about Greenland. Topographically, it is shaped like a bowl. In extreme warmth, the water may not make it over the rim and Greenland would be a swamp.

  6. Ronald says:

    The only thing I have to relate the artic ice melting is what a lake does in the spring. Once there is open water on a lake when it is melting, it will be a short time for all the ice to be gone.

    The artic is of course quite different than a lake. The increased temps in the artic, if they continue, would be enough to melt quite a bit of that ice.
    15 to 20 degrees Celcius would be 27 to 36 degrees F which does seem quite large.

    Good luck on the bets. It will be interesting and I don’t know which way to go.

  7. Earl Killian says:

    I don’t know much about the site, but exists specifically for formalizing this sort of betting. Since right now their webserver is not responding to me, here is an article about them:
    (funny the article mentions Y10K when January 19, 2038 looms so soon).
    It the webserver comes back up, it might be interesting to survey the existing global warming bets.

  8. Ron says:

    I have a $20 bill I want to spend. Anybody want to give me some odds?

    How sure are you?

    You’re not chicken, are ya?

  9. Nick Barnes says:


    Can you give me odds on the ice being back to near normal within the next two years?

    I’ll be happy to take your money. Translating your “near normal” into formal terms, I’ll bet you, at even odds, that we won’t see a zero or positive anomaly for arctic sea ice area any time before the end of 2009.

    You’ll have to identify yourself, and convert your $20 into euros, though. Shall we say 15 EUR? It’s bad enough having to work for USD; I’m not going to bet in them too.

  10. Ron says:


    No thanks.

    I agree with you, though, that the odds of such an event are probably about 50/50, for lack of a scientific way to pin it down any closer. I was just hoping that one of the alarmists would put their money down on what they should think would be a longshot.

    Oh well, I don’t blame them. With all the uncertainty around this, I wouldn’t want to bet the farm on it either. Far safer for them to bet the public’s money.

  11. Nick Barnes says:

    I didn’t say that I thought the probability of it was about 0.5. I offered you a bet at those odds. Do you suppose that bookmakers really set odds at their best estimate of the probability?

    Given the ‘tale of the tape’, the probability seems very low to me, maybe 20%, maybe less. But I like all my bets to be at even odds. Do you want to suggest terms for a bet at evens?

    Didn’t think so.

  12. Ron says:

    No, of course Nick, bookies don’t offer the real odds; they are in business to make money.

    And I’m not so interested in betting that I’d want to play any sort of flip-a-coin game with you.

    I was testing the faith of the warm-mongers.

    $20 is $20. I thought perhaps somebody would take this ‘sure thing’ proposition and give me some odds on it just for fun, but their silence speaks volumes doesn’t it?

    Their faith says the chance of the Arctic sea ice rebounding anytime soon is virtually nil, but they aren’t actually going to test those odds with their own money. As I said, it’s far safer for them to bet with the public’s money.

  13. Nick Barnes says:

    Their refusal to bet with you says about as much as your refusal to bet with me. Your attacks on them as “warm-mongers”, and as people who “bet with the public’s money”, says far more about you.

    $20 is $20, but until you’re prepared to put it down on an actual bet, it’s worthless.

    Several people in the mainstream of climate opinion have offered open bets to sceptics. Very few of these have been taken up. In comparison, very few sceptics are prepared to put their money where there mouth is (by proposing an actual bet).

  14. Ron says:

    Okay. Based on what the Believers are saying about the Arctic ice, I’d say the chances of the ice rebounding within 2 years has got to be no better than 500-to-1. Does that sound reasonable to you?

    Heck, I even think it would be a longshot for it to happen that soon myself! But I’m willing to lose $20 to make a point.

    So, how about a bet on those odds? Will you take my $20 on a 500 to 1 proposition?

    Or do you really think the odds are more like 1-in-5 as you said above? If that’s the case, then I must not call you a warm-monger. But I still wonder what Joe, James, William, or Brian would say the odds are ….

  15. Joe says:

    Do you mean rebounding to the 1979-2000 average?
    There is no chance of that happening. It isn’t worth betting on.
    No, we aren’t, so we don’t offer odds. Sorry.

  16. Ron says:

    500-to-1 would be very conservative odds then. The real odds, in your opinion, is something like infinity-to-1

    Nobody wants an extra $20 just to prove I’m an idiot?

    I’d had the impression you were something of a gambling man, Joe.

  17. Joe says:

    This wouldn’t be gambling. This would be taking the hard-earned money of a single Dad. Sounds like that stealing you’re always complaining about. Plus you’re gonna need all your money to fill up your gas tank….

  18. Ron says:

    The bet is over a 2-year time span, Joe. I’ll save up.

  19. Nick Barnes says:

    No. 500-to-1 doesn’t sound reasonable to me. We’re talking weather here, over the course of two years, so you’re suggesting that rebounding to 1979-2000 average is less likely than a one-in-a-thousand-years weather event.

    We don’t know enough about the arctic sea ice to say whether such a rebound would be a one-in-a-thousand-years weather event, although we can do some statistics to make an educated guess. Eyeballing the noise in the “tale of the tape” graph, it seems unlikely. How many standard deviations would it be? 3?

    So maybe one-in-thirty or one-in-fifty years but not one in a thousand years.

    The situation with arctic sea ice is very clear. There is a long-term trend of ice area loss, and a longer-term trend of ice thickness loss. There are clearly identified feedback effects which make it likely that these trends will continue or accelerate.

    The extent to which these trends are caused by AGW is unclear. AGW contributes directly to them; so does the AO and some unusual weather patterns of the last few years (the AO and the strange weather may in turn be due to AGW to some extent).

    None of this is in dispute by a single scientist studying the arctic sea ice. People who question it politely can be shown the data, the studies, the reports, the satellite photos, the papers. People who heap abuse on the hard-working scientists can go take a running jump into the arctic ocean.

  20. Ron says:


    We’ve already established that you’re not one of the warm-mongers. You’re a Believer, apparently, but you aren’t going to say “there is no chance of that happening,” as Joe did.

    Joe apparently doesn’t really believe what he said, but he’s not going to admit to any uncertainty. As a paid Believer, he has a personal stake in promoting the hysteria.

    The more important bet was the one I had with myself. I was betting $20 with myself, against a zero monetary payoff, that Joe or the others would not take my bet.

    I would have expected to lose the bet, if they had taken it (I don’t think climate changes as fast as they SAY it can), but as you see – despite their professed certainty – they wouldn’t touch that bet with a ten-foot pole!

    And what scientist have I heaped abuse on? Joe is the one who customarily calls skeptical scientists nuts and worse.

  21. Ron, if you’re a skeptic who either disbelieves in warming or thinks it’s natural, then maybe you and I can do business. However, I’d like it to be a serious bet, for serious money. Go take that $20 to buy a pizza, and think it over.

  22. Ron says:

    I’m a skeptic who is getting sick and tired of the fear mongering and hysteria and new proposals for bigger (global) government and more taxes – and I think I made my point.

  23. Joe says:

    The only point made here is nobody is interested in a $20 bet with you.

  24. Ron says:

    But we’re still on with our $1 bet about Al Gore, right?

  25. Joe says:

    Remind me about that bet.

  26. Ron says:

    This one might even be a longer shot than the one above – but who knows?

    I bet you a dollar that Al Gore is going to enter the presidential race at some point.

    I probably would, if I was him; and he seemed pretty broken up about losing the last time. He’s also the one with the good press lately. If he waits until the last minute, he might avoid some of the mud that’s going to be flying. What is the last minute that one

    I’m still predicting Hillary as the winner, though (but I hope I’m wrong).

    Actually, back in the late 90s sometime, I predicted George Bush, and then Hillary as the next president after him. I sure didn’t see him winning a second term, however.

    My original prediction included ‘a black, woman running mate – to be announced’. It will be interesting to see how this season plays out.

  27. PGosselin says:

    The minimums vary already more than 10% from year to year.

    I’d certainly bet on the ice not disappearing by 2030. And sea levels will surely not increase 1 meter in the next 92 years. I’d bet any one on that. And because none of us will be around in 2100, we can take the 10-year trend. That is if sea level rises 10cm or less in the next 10 years, then I win. If sea level rises more than 10 cm during the next 10 years, then I lose. (Excluding volcanic activity under the West Antarctic shelf).
    Anyone willing to accept that bet? Let me know if you’re interested!
    I have yet to find anyone even willing to bet on 5cm in the next 10 years.
    PS: Looking at the link provided, never has the sea ice cover recovered so quickly as in the 2007/08 winter.

  28. PGosselin says:

    I just love the way you’re all climaxing looking at the temperature graphic you show above. True it shows the Arctic getting warmer, but look at the South Pole. This is where 90% of the world’s ice is stored. Looks to me like it’s getting colder down there!

  29. Nylo says:

    I just got news that there is a first report from the ARGOS experiment, which consists of 3000 autonomous devices measuring temperature and salinity of seas and oceans in depths between 1500m and 0m. This report shows no average heating of the oceans at all for the last 5 years (that’s how long the project has existed). If anything, a little cooling.

    As soon as I get a link to that first summary report, I will provide it here. Meanwhile, you can learn about the project details and data at

  30. Nylo says:

    No link to the report yet. However I have an inter view with Josh Willis, a well-known AGR supporter who published 2 years ago a paper,
    critizising the first results obtained by ARGO during 2003-2005, which of course showed cooling, by claiming that the cooling was due to sampling errors. Now, with the results of 2003-2007 still showing cooling, he doesn’t claim the same, either because he was wrong in the beginning or because the posible sampling errors have been corrected with the deployment of new measuring robots without affecting the results.

    The interview:

    The warming seems to be having a break, he more or less comes to say.

  31. amoeba says:

    Speaking as a non-expert. It is my understanding that the interannual variability [noise] is far larger than the climate-change related signature. If it were larger, nobody would voice your opinions, except at the risk of being lynched. At the poles, there will be the polar amplification effect and other feedbacks. Therefore, short-term odds over periods of a few years are probably close to 50:50. What is far more forecastable is that over a longer period the chaotic [not random] noise cancels itself out, leaving the cumulative year on year increase due to climate change. That’s why the climate is measured over 30 years or longer. Short term trends are essentially valueless in statistical terms.

    Your characterisation of people who are convinced by the evidence as ‘warmers’ is objectionable.

    Have you read any genuine science recently? Ever? From your comments, it seems unlikely. N.B. WUWT and Energy & Environment don’t count!
    Q. When did I last read some science?
    A. About two hours ago. See ref.

    Exceptional European warmth of autumn 2006 and winter 2007:
    Historical context, the underlying dynamics, and its phenological impacts
    Luterbacher et al.