Candy from a Baby

A new paper by Lewis and Karoly (2013, GRL, doi: 10.1002/grl.50673) concludes that man-made global warming has increased the odds of hot summer weather such as Australia suffered recently. The paper states, “The human contribution to the increased odds of Australian summer extremes like 2013 was substantial, while natural climate variations alone, including El Niño Southern Oscillation, are unlikely to explain the record temperature.

This last summer saw Australia’s worst heat wave ever, but that was only the worst of the sizzling temperatures that have plagued the continent since November of last year. You can find some of the details here. The heat was astounding. There’s no denying it.

Unless you’re writing for Anthony Watts’ blog, where denial is the order of the day. Willis Eschenbach actually claims, referring to Australia, that “… there was nothing at all unusual about the 2012 summer.” In a later post Bob Tisdale echoes that sentiment, saying “Australia summertime temperatures in 2013 weren’t remarkable.”

The claim is not just wrong, it’s impudently wrong.

Considering just how astounding the heat has been in Australia, especially this last (southern hemisphere) summer, especially during January 2013, how could anyone possibly persaude blog readers that “… there was nothing at all unusual about the 2012 summer“?

It’s so easy, it’s like taking candy from a baby. A group of none-too-bright babies who will tout shoddy evidence as “proof” while calling the thermometer a liar.

All you have to do is use the wrong data.

Eschenbach decides to use satellite data for the lower troposphere from UAH and RSS. Nick Stokes tries to point out that temperature in the troposphere (about the bottom 10 km of the atmosphere) is not surface temperature, which is what the new paper is about. He is shouted down and insulted.

Tisdale goes for a surface temperature data set which is actually reanalysis data (i.e., a computer model fed with observations) which, as Nick Stokes again points out, is known to be biased. In the paper which introduced it you don’t even need to read past the abstract to find that the authors themselves warn “The study also reveals that there are clear biases between the observed surface air temperature and the existing Reanalysis data sets, and they vary in space and seasons. Therefore the Reanalysis 2 m temperature data sets may not be suitable for model forcing and validation.

What if we used actual observations for the actual surface temperature in Australia? What if we actually looked at data for Summertime, and, say, for the month of January?

Australia’s Bureau of Meteorology (BOM) shows last summer as the hottest on record:


It was a scorcher, that’s for sure. But how unusual was it, and how unusual would it have been if not for climate warming? We can get an idea by looking at the trend in Australia summer temperature:


The 2012-2013 summer was 0.73 deg.C above the trend line. Since the standard deviation of the residuals from the trend is about 0.47 deg.C, that puts it 1.56 standard deviations above the trend line. That’s only mildly unusual, corresponding to a p-value of 0.058 — but that’s only because the changes brought about by the climate trend made such high temperatures less unusual than they were before. And that’s the whole point!

That calculation is based on using the normal distribution for the residuals from the trend. That’s at least approximately correct, since the Shapiro-Wilk test indicates no evidence that those residuals depart from the normal distribution, and they don’t show any sign of autocorrelation either.

The trend has shown 0.86 deg.C of warming since 1910. That means that if the same summer heat had happened in 1910, it would have been 1.59 deg.C above the trend line rather than merely 0.73. That puts it 3.41 standard deviations above the 1910 trend value. That isn’t just mildly unusual, it’s astoundingly so, corresponding to a p-value of 0.00033. Last summer’s heat in Australia would have been a once-in-three-thousand-years event, given the 1910 conditions. Now it’s only a once-in-seventeen-years event. The warming of Australia’s climate has made an “angry summer” like they experienced recently, about 181 times more likely.

And that’s the whole point.

If we look at January temperature (the height of summer in Australia) rather than the entire summer (December through February), the picture is even more extreme:


Again, January in Australia was the hottest on record. Again, the trend has been one of warming:


This last January was 0.94 deg.C above the trend, and since the standard deviation of the residuals from trend is about 0.64, that’s only 1.46 standard deviations above the trend. That’s very mildly unusual, with a p-value of 0.0716. But since 1910, the trend of January temperature in Australia has shown an increase of 1.5 deg.C. That means that last January’s temperature was fully 2.44 deg.C above the 1910 trend value, which is 3.8 standard deviations. That is quite amazingly unusual, with a p-value of 0.000071. January temperature that hot would have been a once-in-fourteen-thousand-years event back in 1910. Now it’s only a once-in-fourteen-years circumstance. The warming of Australia’s climate has made an “angry January” like they experienced recently, about 1000 times more likely.

You bet your ass that’s the point.

You can use different data sets, but unless they’re deliberately chosen to give the wrong result (like the folks at WUWT do) you’ll end up in the same place. Using the CRUTEM4 data, for instance, climate warming has increased the odds of an Australian January as hot as this last one by “only” a factor of 63, changing a once-in-640-years event to a once-in-10-years event. Any way you look at it honestly, the chance of an Australian summer, or January, as hot as the last, is a helluva lot greater now than it used to be.

But — if you put blinders on, seize the wrong data and call it “proof,” and you’re willing to call the thermometer a liar, then this last summer in Australia was nothing at all unusual. Expect more of the same.

47 responses to “Candy from a Baby

  1. theinquirer

    The deniers deny they are deniers. Hardly surprising.

    And the oceans will start to cough up their heat in 5 to 10 years. What then?

    • The extra energy sequestered in the oceans is mixed. The water, though slightly warmer, is still exceptionally cold.

      • After reading the recent article by Rob Painting at Skeptical Science, it does sound like the problem is not so much that the deep ocean will cough up the heat later as restrict the flow of warm water to the deep via ocean gyres and encourage more rapid warming near the surface.

      • Which may in part be why Australia was so hot in January. La Nina piles up a large mound of very warm water on the surface of the Western Pacific. Judith Curry claims Trenberth was suggesting violating the 2nd law of thermal dynamics with his suggestion the missing heat will come back to haunt us. I do not see how any reasonable person could think that is what he meant, or thinks.

  2. As the Titanic sank, it’s electric lights were still blazing. Presumably some stayed in their cabins to the end. Perhaps insisting nothing was wrong.

  3. They’re living in their own hologram, trying to inflict the same on everyone else. It’s a mental disease, but the result is a climate melt-down.

  4. Drawing any conclusions from the Oz land temp record is like trying to determine ocean heat content pre-ARGO. Sparse data and in many cases
    bad data ie….many of the older records were recorded in whole degrees or when they converted to celsius in 1972. Save for a few quality stations which amount to a regional effect the Ozzie data should be taken with a serious dose of doubt. Much ado about nothing.

    [Response: Gonzo proves the point. He doesn’t like what the thermometer says, so his comment amounts to nothing more than calling the thermometer a liar. That’s what those in denial have to resort to. But wait, there’s more!]

    BTW how many state heat records were broken during the “angry” summer? Oh none!

    [Response: Bonus points — Gonzo adds “moving the goal posts” to denying the facts. The relevant fact is that last summer, and especially January, was scorching hot in Australia — not that some state broke a heat record. Gonzo hopes that by pointing to one factoid which isn’t a record-breaker he can distract everyone from such facts as:

    During this period, Australia registered the warmest September–March on record, the hottest summer on record, the hottest month on record and the hottest day on record.

    A record was also set for the longest national scale heatwave.

    Does Gonzo actually believe that just because no state heat record was broken, that will magically transform the hottest summer on record nationwide, the hottest month on record, the hottest day on record, and the longest national-scale heat wave, into “nothing at all unusual about the 2012 summer”? Not too bright.

    Perhaps most important for those of us who are interested in the truth, Gonzo has denied the reality of Australia’s scorching hot summer in order to distract us all from the fact that summers like that are now more likely than they used to be, by a lot. He must distract everyone from that fact, because that’s the real point.]

  5. From the Sydney Morning Herald, 1 Feb 2013 (

    “Much of Australia broiled in the first half of January, with eight days of national average maximums above 39 degrees – seven of them in a row, easily beating previous measures for heatwave duration… The national average maximum temperature of 40.33 degrees on 7 January was the highest on record, the bureau said.”

    A continental average of 40C! Sydney, a temperate coastal city, experienced 45.8C at Observatory Hill and 46C+ inland. Try taking candy from a baby when it has all melted!

      • Ian Forrester

        I wonder how long it will take the Fiends of Science to claim that it wasn’t the river that rose but the land next to the river that subsided.

        I haven’t heard if the basement of the Petroleum Club was flooded or not but it would be just dessert if it was.

        PS I live in Calgary.

      • While the Calgary flood is a good example of poor disaster preparation, the event itself wasn’t really all that extreme (from a hydrology perspective) and had little to do with climate change.

        It speaks far more to the folly of developing flood plains while ignoring/forgetting the fact that Calgary has been hit by large floods before. Last weeks event was the third largest in 140 years and only marginally larger than the fourth and fifth.

      • Fair enough, as far as it goes–but the question isn’t “was this an outrageously extreme outlier,” it is “is this something we are likely to experience much more often than before?” As I understand it, the answer WRT flood, 1) theory says yes; 2) precipitation obs say yes; 3) flood data is too incomplete or scattered to allow an answer yet.

        For me, this makes it both relevant annd illustrative, if not suggestive. Definitely worth mentioning. And the side of it you mention–the triumph of greed over foresight–is relevant in another way.

    • Or to put it another way, the new norm is converging on the old extreme.

      Melbourne is more southerly than Sydney, but our new record is higher. I realise the following is anecdotal, but it is illustrative. I come from an area in the Dandenong Ranges where I have had a chance to observe changes over the last 30 years.
      1. There is a well identified process in our temperate schlerophyl forests whereby eucalypt forests, as they age, develop small pockets of temperate rain forest, and these in turn persist until fire destroys them and the eucalypts grow back. Average cycle length is reported to be of the order of 200 years. I have been watching a pocket of rain forest form for the last 25 years. It has died after a series of heat waves. The point? The heat cycle appears to be unusual given that stable climate is required for the rain/schlerophyl forest cycle.
      2. From 1997 to 2010 Southern Australia experienced an extended and almost certainly climatalogically unusual drought. This resulted in, amongst other things a series of major bush fires, on two occasions (2003, 2006) of more than 1 million hectares, and a lethal fire that killed 174 people in 2009 – Black Saturday. In the week preceeding that fire, we had a three day run of something like 43, 44 and 45C temperatures. On the third day the road outside our little stone church melted, high tension lines snapped in the heat and the fire truck coming down the hill to fight the resulting fire broke though the road surface, and slipped. Then week later we had 48C and the disaster day.
      3. To all of us, the worst day until Black Saturday had been the Ash Wednesday fires of 1983, and the hottest a day dubbed Black Friday in 1939 when Melbourne recorded 45.6C and some 70 people died in those fires.
      4. It’s probable that the heat dome of this year exceeds all comers for areal extent of very extreme temperatures, over continental Australia, (1939 was previous). It was concentrated over inland western areas of the continent. In 1939 the heat bubble persisted over some of the most flammable land in the world at that time, south eastern Australia.
      5. If this last heat dome had located itself where the 1939 one was, in 2009, then it’s not out of the question that 10 times as many people would have died.

    • Andrew Dodds


      2012 in England was the wettest year on record. Which would be interesting in itself, except that the first 3 months of that year were classified as a drought. We beat a 12 month record in 9 months.

  6. As as Australian resident, I can personally attest that is was indeed a hot summer.

    But don’t take my word for it. The
    had to invent a new colour to put the heatwave on the map.

  7. Meanwhile in the western US this week:,
    and in Alberta last week
    From an older Tamino post:
    I’ll continue to do what I can, come hell or high water. Expect both.

  8. I’m not arguing anything and I claim no competence but I ask a serious question, however naive or ignorant or dumb…

    The two bar graphs for the “Summer Mean Temp Anomaly” and the “Jan Mean Temp Anomaly” …

    I can squint my eyes and wonder about, maybe, a 50-70 year-ish cool cycle beginning, perhaps, before 1910 which then transitions to a warmer phase of a cycle which we’re now in. Meaning, therefore, that we maybe need another few decade or three to draw any conclusions.

    I suspect some denialists will do just that, perhaps as part of “nothing unusual.”

    Do those graphs, or do the trend lines graphs, together or by themselves, argue against that interpretation?

    I know multiple independent lines of evidence convincingly do, but does the information in the four graphs also?


    • You can always imagine a ‘cycle’ of some kind or other that will fit the data. But unless you are aware of some kind of mechanism that would cause such a shift in climate over the timescales involved then you might as well be blaming goblins and pixies (aka climate elves).

      [Response: Goblins, pixies … what nonsense. How many times do I have to tell you — it’s the Leprechauns!]

    • Gavin's Pussycat

      It’s actually a good question. “Perhaps the warming we have seen over the last century is all natural, part of a natural cycle”. And no, you’re right, these graphs on their own cannot answer this question. What can is: physics. And as you seem to be aware of how convincing this evidence is, I’m not going to rub it in ;-)

      But, there is also a statistical argument. Look at Figure 17 in Manabe-Stouffer 1995. Models and data agree on a simple power-law model for the spectrum of surface temperature variability. There just is no room in that power law for the huge centennial-scale cycle postulated by some denialists. The climate is actually pretty stable, steering itself back to the long-term average on all time scales. To get it out of this balance for any longer time span, requires pushing, and pushing hard — as we are doing. It would be bad news if it were otherwise…

    • I agree that there is a tendency in denialist circles to look at charts independent of what they are supposed to be about. People that do that should be reminded that ‘the map is not the territory.’ In particular, if you think there is a cycle, what is the physical explanation for the cycle?

      Squinting at a chart and saying “I think there’s half a cycle in there.” is not particularly credible. The human eye sees patterns all the time, it is built to do that. This is where you have to pin down denialists to do everything they want real scientists to do, explain their methods, why did they leave some things out and include others, error bars, etc. At some point it becomes clear that it is all just epicycles and astrology, the same chartist technical analysis BS we see in the stock market.

    • Two things–first, the harmonic functions sin and cos form a complete set–you can always fit most of an arbitrary time series if you throw in enough harmonic terms–it is simple Fourier analysis. The fit will be most problematic near the endpoints of the series for any finite sum of harmonic terms.

      Second–and I will apologize for always harping on this example, but it is a good one–consider the following series of data pairs:


      Predict the 11th y-value. If you said 1 or 2, you are wrong. It is in fact 4, because the y values of the pair are simply the digits o the base of Napierian logarithms, e, and the x values are simply their ordinal position. Because e is transcendental, the digits are random, so there is no way it can be periodic. Yet we seem to see five or so periods! What this illustrates is that it is simply foolish to try to fit a sinusoidal function to data unless you have many, many periods of data or you have a physical mechanism that drives the system sinusoidally.

      • Chris O'Neill

        I read about an experiment with rats that tested their response to a choice which was randomly rewarded and they successfully worked out which choice had the highest probability of reward and stuck with that.

        When humans were tested, however, instead of just sticking with the choice that had the greatest chance of reward, they tried to find some pattern in the random variation and ended up doing worse than the rats.

        It seems that the human search for patterns can sometimes be a mistaken strategy.

  9. theinquirer

    WUWT commenters understand stats:

    Bob Diaz says:
    June 28, 2013 at 6:57 pm
    It should be no surprise that every now and then we hear of some record high some place. If the records go back only 100 to 150 years and there are 365 days in a year, every day represents 1 chance out of 100 to 150 that a record high may be broken. Given that there are 365 days of the year, record highs should be broken on average 2 to 4 times per year.

  10. Peter wright

    Shelama. You can answer that question by extending the graph backwards pre 1910 to see if there was a corresponding warm phase (cycles are cyclical naturally) I don’t have the data to hand but I would be astonished if you find anything of similar magnitude.

  11. Well, I’ve found that if I squint hard enough, I can actually close my eyes altogether and make the graphs disappear in their entirety.

    The fact is, while those graphs tell us nothing about why what we’re seeing is happening, they practically scream at us that warming is indeed going on. Of course, one can always cherry-pick to draw their own conclusions (“In either of the two January mean temperature anomaly graphs, 1933 was warmer than 2012, so clearly Australia is cooling!”) But the trendlines don’t lie. And no matter how much one squints, the fact remains that on all four of the graphs shown here, there are far more data points plotted below the zero line on the left side of each image than there are above it, and vice versa on the right.

    The only honest conclusion that can thus be drawn; Australia is heating up. Delusionalists can stomp their feet all they want and whine about “nothing unusual” going on. But that is, simply, ignorance.

    No, we don’t “maybe need another few decade or three to draw any conclusions.” First, the evidence is pretty conclusive as it is. Second, short of global nuclear war, the eruption of a supervolcano, impact from a giant comet/asteroid, or some malevolent comic book villain from beyond the galaxy turning his Super-Duper Giant Interplanetary Cooling Ray on us, physics tells us the planet will continue to warm. Third–and most importantly–we don’t have “another few decade or three” before we do something about our predicament.

  12. Michael Sweet

    In your January graph around 1933 there is a very large spike. How much hotter would it have been last summer if it had been as much above the trend as that summer was? How many standard deviations was it? What is the likelihood of deviation happening again?

    Your posts are always informative.

    It was interesting that Gonzo wanted to remind us all of the denier position.

  13. Thanks, Gavin’s Pussycat, for taking the time to read and understand my question.

  14. Am I right in thinking that these figures mean that in about 85 years, if the trend continues in a straight line, our last angry summer will be the average? That one in two summers will be worse?

    [Response: Now you know why we want to reduce greenhouse gas emissions.]

  15. jiminy “If this last heat dome had located itself where the 1939 one was, in 2009, then it’s not out of the question that 10 times as many people would have died.”

    All during that heatwave last summer, I kept having flashbacks to March 2008, the 1 in 3000 years event. What if that 2013 system was a few degrees of latitude closer to us? was my worry. There wouldn’t be a single refrigerated truck available for all the cool drinks and icecream – they’d be in use as temporary morgues again.

  16. Speaking of comparisons, Michael Sweet asks about the 1933 heat wave.
    Ya know what the sun was doing about then?
    Not much: it was at the bottom between cycles:

    If ya think the sun makes a huge difference, then consider that.

    Aside — go looking for solar cycle charts (images) with Google Image Search and you’ll be quite impressed. WTF is by far the main source.
    It takes a bit of effort to find a reliable source instead. They do the “CO2Science” thing — take good information, slant it, spin it, and advertise it widely as though it were still good information.

  17. Not only was our summer very hot, it also lasted a long time. I cannot remember a period in autumn like early to mid March when, in Melbourne where I live, the nights were sweltering. Night time minimums were above 20 for 7 days in a row in March, which is autumn. In March the mean minimum is 13.2. One thing I have noticed here is that the minimum temperatures have definitely risen over the years. We recently had a string of cold mornings, below 5 for about a week, and I haven’t seen this since I was a kid. Back then it was just normal.

    • Quantile matching of the last 40 years of Melbourne temperatures also shows that the low range of maximum temperatures is rising faster than the high range. So although high temperature records are being set winter days are on average, a little more warmer than summer ones.
      At the peak of the drought I was relating to a group of third graders how when as a child I used to jump on frozen puddles. They looked rather blank. The teacher commented, “You know, not only have they never seen frost, most of them have never seen puddles.” I guess they now have seen puddles.
      I currently reside in Brisbane with summer dominated rainfall in contrast to Melbourne.Last summer the rains were months late and it was very and fires intruded into the outer city. Now much of the state is drought declared while the coast is experiencing very late rains.
      Joanna Nova has just recycled the stupid claims of “not unusual”.

      • I believe Ms Nova lives in Perth, the same city as me. Like most places in Australia we had a record hot summer. But we haven’t had a record hot summer day for some time.

        When I was growing up in the 60’s and 70’s, almost no one had air conditioning. We’d open the house up at night, and then shut all doors, windows, curtains and blinds as soon as it got warm (~8am). There would be a lot more concern about global warming if that was still the case!

  18. The following is a link to last night’s excellent Australian ABC science program on extreme weather.
    [video src="" /]

    It includes interviews with the following climate scientists.
    Dr Erich Fischer, Institute for Atmospheric and Climate Science, ETH
    Dr Karl Braganza, Australian Bureau of Meteorology
    Dr Lisa Alexander, Climate Change Research Centre, UNSW
    Dr Susan Wijffels, Marine and Atmospheric Research, CSIRO
    Professor Jennifer Francis, Institute of Marine and Coastal Sciences, Rutgers University