Global Warming AND el Niño

Some people, especially climate deniers like David Rose, seem to have a hard time grasping the fact that more than one thing can affect global temperature at the same time. Some things, like man-made global warming, bring about a trend that keeps on giving. Others, like el Niño, cause temporary fluctuations that just don’t last.

Yet another article has appeared defending David Rose’s misuse of temperature data. This time it’s Jaime Jessop writing for the “Climate scepticism” blog rushing to Rose’s rescue. His central theme is this:

The main objection to Rose’s article is that he ‘cherry-picked’ land only data from the RSS lower troposphere dataset and ignored the oceans (he did not) and that (bizarrely) he cherry-picked two data points and ignored the longer record. The whole point of Rose’s article is that this is exactly what the media and scientactivists were doing …

That’s not true.

Here is David Rose’s real purpose in his article, in his own words:

Some scientists, including Dr Gavin Schmidt, head of Nasa’s climate division, have claimed that the recent highs were mainly the result of long-term global warming.

Others have argued that the records were caused by El Nino, a complex natural phenomenon that takes place every few years, and has nothing to do with greenhouse gas emissions by humans.

The new fall in temperatures suggests they were right.

I’ve emphasized the part that shows David Rose’s real purpose, which he makes crystal clear by saying it explicitly: to promote the idea that the spate of records (soon to include three record-breaking hot years in a row) has “nothing to do with greenhouse gas emissions by humans.”

Plain and simple: David Rose is trying to deny the reality of man-made global warming. That’s why he is (quite rightly) called a “denier.”

Jessop goes out of his way to show other data sets, to quell criticism that Rose picked RSS land-only data because it shows the recent drop from the February 2016 peak. That includes surface temperature data (for land regions) from NASA, posted on twitter by Gavin Schmidt:


Unfortunately for Jessop, this graph shows what David Rose left out in one of his real indulgences of cherry-picking: what happened before 1997. That makes the trend obvious. Even “blatant.” David Rose didn’t want you to see that, because he doesn’t want you to see the trend, which is why he adds his name to the very, very long list of deniers who use that particular cherry-pick.

Indeed temperature has subsided since the peak in February 2016, because temporary factors like el Niño don’t last. Gavin Schmidt himself has emphasized that often enough. So have I.

In fact, I did so back in March when the peak temperature was “hot off the presses,” when NASA released their data update for February 2016. I posted about how it was a record-breaker; so did a lot of people. But I also made it abundantly clear that what really matters isn’t the fluctuation (in this case el Niño), it’s the trend. Here’s exactly what I said:

I like to emphasize that what matters most is the trend:

It’s going up. Has been, steadily, no pause.

The continuing barrage of record-breaking heat is remarkable. That’s because of the trend. Of course there’s fluctuation too, but without the trend we wouldn’t see records getting smashed again, and again, and again, year after year, month after month. We’re sure to see times again — soon — when the fluctuations go the other way and we get a respite from record-breaking heat. But that respite will be brief, because fluctuations will turn hot again too; that’s what they do. When they do, they’ll be added onto an even hotter trend value, because the trend isn’t going to stop any time soon.

Any way you look at it, not only was it a scorcher of a February, the trend is rapidly taking us down the path to worse trouble than we’re already in.

Let’s get to the main thing David Rose and a whole lot of other climate deniers just can’t seem to wrap their heads around. It’s a wee tiny bit more complicated than a 5-second sound bite, so maybe it’s just too much for them.

We’ve had big el Niño outbursts before, but the recent ones have brought record-breaking global temperature. That’s because lately, el Niño peaks have been added to such high trend values. Global temperature is affected by both, and when they conspire to bring the heat, the heat is incredible. Newsworthy. Well worth being discussed, and pointed out to the public who will end up suffering the consequences of our inaction to put a stop to global warming.

Let me give (once again) an analogy which is perfectly appropriate. Sea level is on the rise, and because of that, when very high tide comes to Miami it floods the streets. They didn’t used to flood even with high tide. Nowadays, because of the rising trend from global warming, when they conspire it brings a peak big enough to spell real trouble for Miami.

David Rose’s argument is just like saying that the latest “king tide” which flooded Miami was followed by a strong low tide, so the flooding “has nothing to do with greenhouse gas emissions by humans.”

James Delingpole’s complaint that the temperature drop following the el Niño peak wasn’t heralded by the press and scientists, is just like whining that the low tide following Miami’s latest high-tide flood wasn’t heralded by the press and scientists.

Strong high tide, especially the “king tide” that comes each year, isn’t the reason for Miami’s flood problem. The reason is global warming, because it’s sea level rise that has turned king tides into floods. El Niño isn’t the reason for the record-breaking temperatures. The reason is global warming, because it’s the trend that has turned el Niño peaks into record-breakers.

I know that’s oh so difficult for David Rose and James Delingpole to grasp — it involves two steps of reasoning — but their inability to “get it” doesn’t alter its truth.

David Rose really did pick two data points — the latest el Niño peak and its following trough — in order to distract us from the trend. Toward the end of his piece, Jaime Jessop lists that as one of the objections raised by Stephan Lewandowsky in a critique. But the only “defense” he offers is “Highly amusing. Psychology professor criticises journalist for misrepresenting climate science!” If you’re going to indulge in ad hominem you should at least offer some fact or reasoning to back it up.

Jaime Jessop’s defense is a disgrace. It credits Rose for objecting to cherry-picking a few data points and ignoring the longer record, when that’s precisely what Rose does, while totally avoiding what he did actually say — his real purpose — pushing the false idea that recent record-breaking heat has “nothing to do with greenhouse gas emissions by humans.”

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24 responses to “Global Warming AND el Niño

  1. Keith McClary

    Physically, Nino and Nina just affect how much of the heat balance is going into the oceans. They don’t affect the total heat balance, although they temporarily fluctuate surface temperature. Your statistical analysis is good, but it obscures the physics.

    • That’s not entirely true. By changing the surface temperature, and also the cloud distribution, the ENSO cycle will have an influence on the heat balance.

      The main point is that over a long time period this influence will average out to zero, and that’s exactly the point that tamino makes.

  2. We all know that 2016 presages another decades and a half of “it’s a pause, therefore no global warming!”

    Here’s a question for the Denialati: when was the last time that there was statistical-significance in the global warming trend for a preceding decade (or 11 years, or 12 years, or…)? For a gold star and an early mark, what import does the answer to the previous question have on the issue of detecting a global warming signal in the short-term year-to-year fluctation of global temperature?

    I’d be willing to bet that there’s not a climate science denialist on Earth who could or would answer both questions honestly and with appropriate use of statstical understanding.

  3. Another thing I’d point out is that the September-November average for 2016 – the destination of this temperature plunge from the beginning of the year – is still the second warmest in the RSS TLT3.3 land+ocean overage, only just behind 2015. In the current UAH iteration it’s the warmest SON avarage by more than 0.1ºC.

  4. I’ve written a brief response to this critique of my efforts to defend Rose here:

    • Let’s see.

      1. “As a Pause Denier of course, Tamino would have his readers believe that this trend has been operating essentially unimpeded throughout the 21st century.”

      Bullshit. Tamino has published numerous blog articles using change point analysis to show exactly when the statistical argument can be made that the trend has changed in the 20th Century. In particular he identifies 2 points but the 1998-xxxx period does NOT meet the statistical criterion for a true change.

      2. “The Met Office conceded that 2014 could not be statistically distinguished from a series of several other possible warmest years in its data after 1998, because . . . . the Pause!”

      Bullshit. There was no such “admission”. The probability was clearly reported by NASA at the initial press conference. 2014 could not be distinguished statistically from 1998 because the values are within the error bars to some extent. This is true of most values close together in any trend analysis. No “admission” is required. Just statistical competence.

      3. “Statistically significant warming started in 2015 – strangely coincident with the start of El Nino 2015/16 ”

      Bullshit. There is no statistical analysis that shows significant warming in the 2015 to 2016 period.

      4. “It stands to reason that El Nino pushed temperatures into record territory from an elevated baseline – the ‘step change’ of 0.2C or so created by the former super El Nino (which added to the long term warming trend – man-made or otherwise).”

      Bullshit. A step change is INSTANTANEOUS and does NOT figure into the trend. If you can come up with a physical mechanism for such a step change in climate you are a better scientist than any other scientist on the planet.

      • “Statistically significant warming started in 2015 – strangely coincident with the start of El Nino 2015/16 ”

        Very strange, indeed, since without specifying some antecedent period, this statement is utterly meaningless… and there is no such reference anywhere in the comment in question, which I took the trouble to look at. That’s 15 minutes of my life I’ll never get back.

        To be just a bit more explicit about my point, warming in 2014 would have been statistically significant for periods beginning in 1997 or earlier. 17 years… oddly enough, Santer et al, a few years ago, showed by Monte Carlo simulation that that’s about the shortest time span for which you can expect statistical significance, based on the properties of observations of GMST so far.

    • Jaime,
      You call that a “response”? You didn’t address a single point Tamino made. Pathetic.

  5. Jamie, give it up already, you are trying to defend the indefensible.
    Besides, is it lost on you that trying to defend a serial liars like Rose and Delingpole reflects incredibly poorly on you? I guess you just don’t care about ethics ;)

  6. The kind of feverish, aggressive response I expected on here. You really do get worked up don’t you.

    “2. “The Met Office conceded that 2014 could not be statistically distinguished from a series of several other possible warmest years in its data after 1998, because . . . . the Pause!”

    Bullshit. There was no such “admission”.”

    “That means the uncertainty in temperature measurements can be larger than the difference between individual years, which typically comes down to just a few hundredths of a degree.

    It’s for this reason, the Met Office can’t say for absolute certain which of many recent warm years was officially the hottest. Colin Morice explains:

    “Uncertainties in the estimates of global temperature are larger than the differences between the warmest years. This limits what we can say about rankings of individual years. We can say with confidence that 2014 is one of ten warmest years in the series and that it adds to the set of near-record temperatures we have seen over the last two decades.”

    How’s that for bullshit?

    • Nevertheless, it warms….
      Do you know much about radiation physics?

    • Jaime, my boy, you’re the only one swearin’. Yes, there are uncertainties on measured temperatures–that is how you know it’s science–but when you have 3 consecutive years, all warmer than all the rest, and each warmer than the last, it’s a pretty darn good bet that there is an underlying trend.

      Do you seriously dispute that it is warming?

      Wow! Al Gore used his time machine to go back in time and fudge the data on the cherry blossom festivals going back to 1000 AD. If only he’d use his powers for good!

    • Yep, putting up with 28 years of ignorant and often maliciously fabricated bullshit from the likes of you, David Rose, David Whitehouse, Ross Clark, James Delingpole and Lamar Smith ad nauseam will tend to get even the most level headed rational person worked up. Deal with it cupcake.

    • Pretty darn fine bullshit actually. Apparently, in your view, the statistically appropriate way to analyze data for positive trends is to look for successive end points which are statistically above the measurement error of picked start points. Anyone even marginally competent in statistics would know that it is trivial* to come up with rising, flat, or negative regression trends from data which meet your apparent condition. Trend analysis looks at ALL the data.

      *Trivial to show a declining trend with an end point “significantly” higher than the start point:
      1. set up a generally declining distribution going from 17 to 1 which represent temps measured to +/-1 degree.
      2. Change the final value from 1 to 21…i.e., 4 times the assumed measurement error and therefore “significantly higher” than the start point.
      3. Run regression and note significant DOWNWARD trend of -.61. The end point is, incidentally, not only much greater than the start point but is more than 4 standard deviations above the CI of the trend line at that point. Doesn’t matter. The trend in ALL the data is still downwards.

      A very simple R script showing and plotting this is available at http:/

      Why people try to post stats BS here is beyond me.

      • Bad edit. Should be: “…but is more than 4 standard deviations above the trend line at that point.”

    • Jaime Jessop, you allude to the issue of year-to-year variability. Perhaps you could get to the nub of the matter and answer the questions I posted above.

  7. Jaime,

    Re: “How’s that for bullshit?”

    Pretty good, actually. It refer to error margins with the 2014 global surface temperature record. The very next year, 2015, smashed the 2014 record and was the warmest year on record by a statistically significant margin according to every global surface temperature producer there is.

    Did you forget that 2015 happened already?

  8. Kneebone, Geoff

    Hi Tamino, I passed this on to a friend and this was his response: “he has ignored other major influences on the global temperature, such as the record IOD in 2016; surely a record hot Indian Ocean close to Asia is too big to neglect in the exercise, rather than attributing it largely to el Nino; aerosols!?! “ Wondering if this comment is valid Thanks

    [Response: And the IPO and the AMO and the QBO and the Madden-Julian oscillation … and don’t forget the leprechauns! What’s his point? The subject of this post is the influence *of el Nino* — on which a lot of deniers blame the entire thing.

    Some people use “other influences” as an excuse to believe that greenhouse-gas increase isn’t important. That’s foolish.

    If he can establish (even better, quantify) the influence of other factors, we’ll all be glad to read his published research.]

    • In recent paper about the possibility of a prolonged pause, which Professor Curry deemed an important paper, there is this paragraph:

      The synthetic series in Fig. 5a also show examples of greatly accelerated warming lasting a decade or more, which are evidently spring-back effects as an internal variability cooling episode is followed by a strong internal variability warming episode. The strong warming episodes are further amplified by the underlying forced warming trend. One extreme example shows a warming of almost 1 °C in 15 years—a much greater 15-year warming rate than has occurred in the observations to date (red curves). These spring-back warmings illustrate another important potential consequence of strong internal multidecadal variability as simulated in CM3, and reinforce the need to better understand whether such internal variability actually occurs in the real world.

      They do not want to talk about the above paragraph.

      (When they use “extreme” they do not mean extremely unlikely. They mean a 1℃ increase in 15 years would be an extreme amount of warming to endure in such a short period of time.)

  9. I printed off a graph of Hadcrut 4 global data from 1950 onwards and marked the strong and very strong el Nino years on it which I found here

    The result shows exactly the same trend in warming as the main series.

    I don’t know how to put that data on here, but it is pretty easy to do for yourself.

  10. Snarkrates my boy/girl/man/woman,

    “Jaime, my boy . . . ”

    Confirmation bias might at least have told you that all sceptics are middle aged white males. In this particular case, only two of those adjectives apply.

  11. Forget “believe”. Try “observe”.