The Hiatus, Continued



news story (Jeff Tollefson):

A new study adds to mounting evidence that cooling in the tropical Pacific Ocean is the cause of the global warming hiatus, a slow-down in the rise of average temperatures that began around 1998.

The eastern equatorial Pacific is well known to have an outsize influence on global weather. Years-long ocean trends such as El Niño and La Niña cause alternate warming and cooling of the sea surface there, with effects on monsoons and temperatures around the world. Now a modelling study by researchers at the Scripps Institution of Oceanography in La Jolla, California, indicates that a decadal La Niña-like cooling trend affecting as little as 8% of Earth’s surface can explain the slower rise in global temperatures.

“The equatorial Pacific cooling turns out to be strong enough to offset the general rise in temperature induced by anthropogenic greenhouse gases,” says Shang-Ping Xie, a climate modeller at Scripps and co-author of the study, which is published today inNature1. Just as importantly, he says, the model helps to explain regional trends that seem to defy the global warming hiatus, including record-breaking heat in the United States last year, and the continued decline of Arctic sea ice.

New Kosaka and Xie paper (link is not live yet as I write)

press release:

related paper in press:

related and consistent work by Rahmstorf :

media release:

Chris Mooney’s “explainer”:

There’s more in the pipeline; P3 will update as it becomes available.


Australian Science Media Centre:



Here’s John Abraham’s post about his paper.

And here’s Fiona Harvey’s article about the Nature paper for the Guardian.

The confuse-o-sphere weighs in:

Tisdale at Watts’:

Judith Curry whose “mind has been blown”:


  1. Trenbreth says that the Hiatus was caused by the exess heat going into the oceans... that must mean (that last time I took thermodynamics) that the oceans are warming. Now you say the Hiatus is caused by the oceans cooling. Which is it?

  2. Yes, we are in a preferentially La-Nina-esque period. This does mean deep upwelling, though I'm not sure there is a "deep humboldt" involved.

    One of two things is happening.

    1) Climate change is shifting the Pacific climate to a more La-Nina-like state. In this case, the hiatus will end and there will be a flat stretch in the surface heating curve.
    2) The El Nino/La Nina climate has not changed, and we just have had a random stretch of relatively cooler tropical Pacific temperatures. In which case the system will bounce back to the long-term heating pattern with a vengeance at some point.

    The good news on #2 is that if it's true it does not appear that next year will be the time. Preliminary evidence is calling for neutral conditions this winter.

  3. Just a minor quibble: there is no "global warming hiatus." There's a hiatus in the warming of the atmosphere.

    Either that or we're all wasting our time worrying about CO2. My money is on "time well spent."

    Is it so hard to understand that the public will be confused when simultaneously being told that CO2 is an inexorable threat and that the process of warming is a halting affair? Entrenched energy interests would pay breathtaking sums to introduce this kind of dissonance into the public mind but they don't have to; scientists and journalists work together to make a mess of our cognition.

    Scott: "Which is it?" More than superficial is what it is. Think about it.

  4. Hrzftsgrtz!!! DAMNED NONSENSE!

    Sure it's nice to know how come the fluctuations, BUT:

    There is no hiatus.
    Neither is there not a hiatus.
    Both is statistical nonsense,
    Obvious upon eyeballing the data
    (I wish they had a 10y running mean, not 5y)

  5. If what you are saying is that the Hiatus is caused by some of the ocean getting cooler and some of the ocean getting warmer that sounds like the ultimate in Ad-Hock ism. You will always be able to find some of the earth getting cooler and some of the earth getting warmer - its called natural variability.

  6. Since Trenbreth did not provide a mechanism for the heat to go from the atmosphere to the lower levels of the ocean, and since we are talking about the same amount of heat, that which would make the atmosphere not climb in temperature for 10 to 15 years, it is much much more reasonable to assume the heat went from the surface of the ocean to Trenbreth's depths (the ocean simply overturned). That would make the depths of the ocean warmer and the surface colder. Occam s razor!

  7. Synchronicity, just reading this:

    For my quote, however, I'm going to use Joe Romm's summary, which brings in some other material and simplifies a bit:

    So we have up to 0.9°F warming from acidification this century that isn’t in the IPCC’s Fifth Assessment Report models. You can add that to the carbon feedback from the thawing permafrost — also unmodeled by the new IPCC report — which is projected to add up to 1.5°F to total global warming by 2100.

    That means actual warming this century might well be 2°F higher than the IPCC projects. In the case where humanity keeps taking little or no action to restrict carbon pollution, that means actual warming by 2100 from preindustrial levels could exceed 10°F.

  8. "Since Trenbreth did not provide a mechanism for the heat to go from the atmosphere to the lower levels of the ocean..."

    Probably because doing so is somewhat akin to expecting your doctor to explain why it's a bad thing that oxygen can't enter your circulatory system as easily when you have pneumonia; the expectation is that your expertise on your own metabolism encompasses the concept of oxygen as a metabolite.

    But it's easy to get informed; just one mouse click away:

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