Reposting: Scientists Predicted Jump in Temperatures

March 13, 2016

The new global temperature graphs from this week are causing gasps across the scientific community. I’m reposting here my 2014 interviews with Kevin Trenberth and Gerald Meehl, who both spoke about the possibility of a “step change” in global temperatures, somehow initiated by large El Nino events, such as what we saw in 1998, and this year.

Worth showing to anyone who thinks scientists do not have a handle on the basic physics of climate.
——, Sept. 14, 2015:

Above, my interview with Kevin Trenberth in 2014.  We agreed that if certain predictions came true, that I’d make sure the video got recirculated – and with today’s new announcement by the UK Met Office, a burgeoning El Nino in the Pacific, and 2015 looking like the warmest year ever – blowing the doors off 2014 – now is that time.

Dr. Trenberth spoke about large cycles in the Pacific that are part of natural variability, and how the ocean has tended in recent years to take more heat into greater depths, where it can not show up on surface temperature measurements.

Dr. Trenberth further predicted, starting at about 9:00 above, that a new El Nino event, if strong enough, like the one we are seeing now, would jumpstart the kind of warming trend that we saw between the mid-70s and 1998.

El Nino years tend to be hotter.

Recent measurements show that the current El Nino is looking a lot like the 1998 mega-event.

In a recent piece in Science magazine, Trenberth expanded on the idea, with a helpful graph showing the “stepwise” motion of global mean surface temperatures, (GMST) with the swings of the Pacific Decadal Oscillation. (PDO)

He wrote:

The main pacemaker of variability in rates of GMST increase appears to be the PDO, with aerosols likely playing a role in the earlier big hiatus. There is speculation whether the latest El Niño event and a strong switch in the sign of the PDO since early 2014 (see the figure) mean that the GMST is stepping up again. The combination of decadal variability and a trend from increasing greenhouse gases makes the GMST record more like a rising staircase
than a monotonic rise. As greenhouse gas concentrations rise further, a negative decadal trend in GMST becomes less likely ( 13). But there will be fluctuations in rates of warming and big regional variations associated with natural variability. It is important to expect these and plan for them.

Dr. Trenberth further predicted, in 2013, that an anticipated large El Nino might trigger a phase change in the Pacific Decadal oscillation, and a new step up in global temperatures. This seems to be playing out now.

In a 2014 interview, Trenberth’s colleague at the National Center for Atmospheric Research, Gerald Meehl, spoke about the contributions of natural variability to the perception of “pause” in surface temperature.  The interviews taken together give a strong impression of how well the senior climate scientists have understood and anticipated the dynamics of global temperature, even with the unpredictability of internal cycles like El Nino and PDO.

In this case, Meehl is talking about “decadal climate prediction” – a new way of climate modeling.   In a traditional climate model, the model is “initialized”, or begun, with the conditions known starting in 1850 and allowed to run with the random variations playing out in the artificial system.  In the new methodology, the models are “initialized” in the 1990s – updated with actual conditions at that time – and they do tend to show with some skill the slower rise in surface temperatures of the past decade or so.

Meehl points out that after the huge, and hot, El Nino of 1998, the pacific went into a large La Nina, or cooling, phase, that in effect, we had not come out of, until recently.  Now the UK Met Office paper out this week is confirming that Trenberth and Meehl’s insights have been prescient.


Here, my most recent interview with Trenberth, from December 2015 :


9 Responses to “Reposting: Scientists Predicted Jump in Temperatures”

  1. Anyone can get a step change if you fabricate the data!

    • Predictable denier behavior: Those who aren’t competent enough to analyze the data themselves will attack those who are.

    • Torsten Says:

      And yet even Christy and Spencer’s UAH satellite temperature record, adjusted in Version 6 to “fabricate” lower temperatures relative to their previous version, shows a record high anomaly for February 2016. Care to explain that, SS?

    • redskylite Says:

      And I suppose the Japan Meteorological Agency, the Hong Kong Observatory and even the Russian temperature measuring agents are in the very same conspiracy. You are delusional, you cannot accept the facts.

    • What ScSc really means: “I will never ever accept any evidence that goes against my beliefs. I’d rather live in my little fantasy land made out of conspiracy theories and other delusions.”

  2. John Scanlon Says:

    Climate in the news from Sydney:

    It was 41 C again today in Perth. Days like this one can’t help wondering, what if the temperature anomaly’s even higher next month? Or like the cartoon with that news story where the kid asks ‘how many weathers make a climate?’

  3. On your graph from 1994 to 2012… have the titles reversed. 1994 – 1998 was El Nino (warming)……and post that was La Nina (cooling).

  4. […] A senior scientist cautions me to keep this in mind – and especially in climate communication efforts, not to create an expectation that this is going to continue on a steady rocket like February – at least so far as we know. We expect there will be a leveling out, after which temps will fluctuate around a new, hotter “stair step”, as Kevin Trenberth predicted several years ago. […]

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