Climate Change: Important thoughts from an insightful thinker

25 responses to “Climate Change: Important thoughts from an insightful thinker

  1. Do compute the probability of an ice free Arctic this year. Like the guy claimed scientists would worry about in the first minute of the video. Will need a world-class statistician to handle such small probabilities right.

    • I’m certainly not a “world-class statistician” Victor. However whilst it’s very early days I am of the opinion that 2019 certainly has a greater than a 0.2% chance of beating the 2012 minimum Arctic sea ice extent record:

      Currently extent is significantly below 2012, albeit somewhat above 2016 at the same time of year. And what of melt ponds? In 2012 there was evidence of less snow cover over land and more surface water on the ice on the Siberian side of the Arctic:

      Other than that Arctic sea ice in 2019 looks to be in worse shape than in 2012.

      What do you make of my a priori evidence? Does that change the odds of beating the magic million this year?

  2. KiwiGriff.

    Victor .
    When they talk of the ice extent measurement they are referring to data where more than 15% of Ice coverage per 25kmx25km grid unit is given as 100% extent for that grid unit.
    I am sure Tamino could do some of his tricks in deducing trends and uncertainty per the normally referenced extent data.
    The noise is quite high with the lowest extent so far being 2012 and this year presently well under that .
    Such an event is really just down to the weather conditions over the last few months now.

    I am not so sure the data is even meaningful in the real world we now see.
    An extent of less than 1,000,000 sq km is the commonly excepted threshold for a blue ocean event . With the fragile nature and lack of old ice now existing we could possibly have less than a real world 1,000,000sq km of ice cover yet have over 4,000,000sq km extent show up in the data.

    I suggest reading the arctic sea ice forum to keep up to date if you are interested. They have a yearly sea ice extent thread always running that is updated with trends and comparison to previous years frequently along with informed comment .

    • MASIE uses a 4km grid, so a much higher resolution than other data sets. The latest graph is given here: and shows an extent significantly lower than the previous 4 years (which don’t include the record year).

    • One of the possible causes of the we-have-12-years myth is the last IPCC special report writing that there is a 2.5% chance that Arctic sea ice will be gone in summer before 2030. So a very coarse estimate would be that the chance it is gone this year less than 0.2% or 2 in a thousand.

      I tend not to worry about symbolic events happening with this probability. I worry about climate change, the inequality-corruption complex, a global trend towards fascism, species loss, poverty & healthcare. To mention a few non-personal problems in no particular order.

      Worry is a big name, but I wish a significant percentage of my side would not act like climate “sceptics” when it comes to the Arctic.

      • KiwiGriff.

        Gone in Summer = Blue arctic ocean for three months.
        BOE less than 1,000,000sqkm extent even for one week.
        Apples to oranges.
        Blue ocean is not just an obscure milestone.
        The resulting albedo reduction will have a significant feed back effect on the future warming of the arctic region and resulting impact on world wide climate systems.

        Not that I am interested at getting at you Victor I definitely respect your expertise and your intent. I just think you should cut him some slack.
        Just have a think is not targeting a knowledgeable audience his content is well thought out for educating the 95% we urgently need to bring up to speed .
        I have been following climate change blogs including yours for almost a decade. The most important thing I have learnt in that time is how much I dont know and how complex the subject really is. I know from reading open mind that statistics is far more complex than I can hope to fully understand without doing a high level degree . Tamino manages to address his difficult subject at a level that brings along even the most ignorant of us. Reading this blog has given me tools to address some of the arguments I come across out in the world on my own . If Just have a think serves the same purpose for others it has immense value .

  3. russellseitz

    Carnival Trump Lines invited bids for a 4,000 passenger icebreaker weeks ago.

  4. David Lewis

    I’m not that sure Pompeo can compete with Jim Inhofe, if he wants to be included in the pantheon of the great thinkers who have thunk the insightfullest thoughts. There’s only so much room on a list like that.

    Eg: Inhofe confessed to Rachel Maddow on air:

    “I was actually on your side of this issue when I was chairing that committee and I first heard about this. I thought it must be true until I found out what it cost.”

    And there was also the time Inhofe displayed an entire data point, a snowball, to the US Senate, which in his mind proved that climate change was a hoax. (Chuck Todd thought this was a clever stunt.)

  5. I think Wadhams predicted the blue ocean event for September 2016 plus or minus three years. I was not a math major, does that mean September 2019 is in the Wadhams window for the blue ocean event?

    • Yes, though it wasn’t actually Wadhams, it was Wieslaw Maslowsky, of the Naval Observatory:

      Wadhams championed the claim with considerable energy, though, as here:

      Often, he made the attribution to Maslowski, for whose work he expressed admiration, but not always.

      So, the “Maslowski window” will indeed close, one way or another, this September. At this point, I’d have to say the odds are high that we won’t see a ‘ice-free’–i.e., sub-1meg–Arctic within that window. (Though we won’t be able to say that with reasonable certainty for a while–probably not before late June at the very earliest–and though there would seem to be a pretty decent chance for a new record low minimum, if the weather ‘cooperates.’)

      But it’s equally clear that that’s where we’re headed at some point; claims of ice ‘recovery’ are quite simply laughable: we’ve had numerous and lengthy periods of record-low extent for the time of year–and indeed, we are in such a period now, as the video mentioned. It’s basically just luck that none have happened to fall at the annual minimum since 2012. That record low minimum is coming, and another, and another.

      The only good news in that regard is that model work suggests that, should we ever get on a path of declining atmospheric GHG concentrations, the ice would regenerate. Eventually. In other words, by itself it’s not necessarily a true “tipping point” in the sense that the new climate state is stable and unalterable. But that might not make much practical difference any time soon (by which I mean “during the lifetimes of contemporaneous humans”).

      • Here’s Wieslaw Maslowski in conversation with Guy McPherson recently about that “controversial projection”:

        Before jumping to the obvious conclusion note that Guy just asks some questions and Wieslaw offers some sensible answers.

  6. Thanks, Jim. A good interview, indeed. Interesting to see Maslowski say, “I’m glad to have been wrong about that projection”–especially based on the current model-based prediction effort which they are running, apparently with some demonstrated skill, for six-month windows. (I.e., the current iteration predicts a 2019 minimum that will not fall below 1 Meg. Too bad he never says what that number for the upcoming minimum actually is, though.)

  7. FWIW — I did a simple linear regression of year vs Arctic Sea ice extent (NSIDC data for the September minima) with a goal of estimating the year Arctic Sea ice will match the 2012 minimum, and the year it will reach 1 million sq km. The 2012 extent seems somewhat of an outlier, so I did the regression both with and without the data for that year. Leaving out 2012 data, the regression predicts the 2012 minimum will be approximately matched by 2031 or 2032 (95%CI: 2027-2040), and 1 million sq km will be reached by about 2062 (95%CI: 2053-2078)). Incorporating the 2012 data gives similar results: 2012 levels again by about 2029 or 2030 (95%CI: 2025-2035), and 1 million sq km by about 2059 (95%CI: 2050-2071). These results assume linearity of the current trend extending to those dates, which obviously is not a safe prediction. However, the quality of the linear fits from 1979 through 2018 is pretty good: R^2 of 0.788 and 0.77 respectively for the two plots, and P values of 5.73e-16 and 9.993e-14 for the two plots.

    Fitting parameters for the linear fits were as follows:
    Excluding 2012 data: y = 160.27 (95%CI: 131.08 to 189.46) – 0.07723x (95% CI: -0.0918 to -0.0626).
    Including 2012 data: y = 167.92 (95%CI: 138.92 to 196.92) -0.0811x (95%CI: -0.0956 to -0.0666).
    No correction for autocorrelation effects was done. Not sure how much difference it would make in the confidence intervals.

    A second order polynomial fit of the same data predicts 2012 levels in either 2022 or 2025 (including or not including 2012 data in the fit, respectively), and 1 million sq km in 2037 or 2040 for the two fits. R^2 values for the polynomial fits were about the same (0.79-0.8) as for the linear fits.

    So time will tell which model fits best. But I wouldn’t bet more than you can afford to lose on a new record September low in 2019.

    The four data fits project to a zero value for the September minimum in, respectively, 2075-6 , 2071-2 (confidence intervals ca. +/- 15 years), 2043, and 2046 (linear fit without, then with 2012 data; polynomial fit with and without 2012 data).

    Whether this kind of modeling is actually useful or relevant is another question. It’s just looking at the numbers without regard to any of the detailed on-the-ground (or ice) studies that are being done.

    • Personally I’m inclined to think this kind of modeling is not terribly useful when it comes to the summer sea ice melting season. For my own views on that thorny topic please see:

      A couple of years ago I was asked to provide “a handful of things [you] will be keeping an eye on over the next few months to judge how ‘good’ or ‘bad’ the melt is going?”

      My answer was, and remains:

      “5 fingers worth to start with? Not necessarily in order of time or importance!

      1. How soon melt ponds and/or open water hang around in the Beaufort Sea this year. Things started very early [in 2016]

      2. Ditto the Bering Strait and Chukchi Sea

      3. Ditto the Laptev and East Siberian Seas

      4. How many (and how deep, warm, wet) spring cyclones spin around the Arctic Ocean

      5. How the snow melt progresses across Canada, Alaska and Siberia”

    • Way over my head on the match, Robert. It’s not my area of expertise at all, but I think that the hockey stick thing kicks in at some point and then linear goes out the window. I am willing to bet $100 USD that the BOE by 2040 or before turns out to be correct. We will have to put money in escrow because I don’t expect to be present when the BOE occurs. I hope that turns out to be the case.