Trenberth: null and void

Trenberth: null and void (2011-11-03). Anthony Watts finds an excuse to make insulting references to a climate scientist. Will wonders never cease? Seems hard to reconcile with his regular calls for niceness.

This time Anthony’s decided that the scientific insights of a British publicist named Ben Norman will be his means of unraveling the global warming fraud. Anthony throws in references to Eurekalert and Wiley-Blackwell to give the appearance of scientific legitimacy, but I think he’s hoping no-one actually reads past his misleading headline.

Norman simply grouped together three recent papers, Ken Trenberth’s provocative “null hypothesis” paper and responses by Dr. Judith Curry (you know, the sciencey wiz who’s decided that eyeballing trends and muttering vaguely about uncertainty is as hard as anyone should have to work) and Dr. Myles Allen (who thinks that Trenberth’s idea is too radical but “Curry’s counter proposal to abandon hypothesis tests is worse”).

I know that Anthony’s mainly trying to smear Dr. Trenberth, but it seems odd that he’s mocking the idea that the default scientific presumption should be that humans are affecting our environment. That’s what underpins his juvenile “surface stations” project! Yeah we’re warming the Earth, but only in a few tiny spots and only in a way that hides the real climate trend (anything other than warming).

His readers comments are the usual assortment of ignorant profundities and jealous paranoia.

4 thoughts on “Trenberth: null and void

  1. From Trenberth’s Abstract:

    Past attribution studies of climate change have assumed a null hypothesis of no role of human activities. The challenge, then, is to prove that there is an anthropogenic component. I argue that because global warming is “unequivocal” and ‘very likely’ caused by human activities, the reverse should now be the case. The task, then, could be to prove there is no anthropogenic component to a particular observed change in climate, although a more useful task is to determine what it is. In Bayesian statistics, this change might be thought of as adding a ‘prior’. The benefit of doubt and uncertainties about observations and models are then switched.

    “In Bayesian statistics, this change might be thought of as adding a ‘prior’.”

    Ben could you explain the above sentence in a bit more detail?
    ps. I’m no statistician.

    [I'm not a statistician either and I didn't write Trenberth's abstract, but to quote Wikipedia:

    "Intuitively, the comparison of freshly generated events to those predicted by each model will cause the judgement of uncertainties to change. In Bayesian inference, Bayes' theorem is used to calculate the necessary adjustment. Over each adjustment, the initial uncertainty is called the prior, while the modified uncertainty is called the posterior."

    I think Dr. Trenberth's basically declaring that the "initial uncertainly" is long gone. Best of luck with your own challenge of Anthony's blog. - Ben]

  2. Hi Ben,

    OT but I wanted to run an idea past you:

    Looking at BEST, since about 1990 all Anomalies are positive, this means that every year since has had above average temperature resulting in an increase in Annnual Average Temperature every year over the period, meaning there has been no pause, at all, statistically significant or otherwise.

    The focus on Anomalies has meant that the most relevant Metric, Annual Average Global Temperature has been overlooked.

    The search for a positive slope over Anomalies has been an inadvertant search for Accelerated warming, not warming.

    [Glancing at Figure 1 in the draft of "Decadal Variations in the Global Atmospheric Land Temperatures" the anomaly is divergence from the mean of 1950-1980 so the anomaly is not from a rising trend but from a static reference. - Ben]

    • A repeated positive Anomaly from a static baseline means that the Annual average Global temperature is increasing meaning there is no Plateau, pretty basic averages theory.

      How can this be when everybody is saying that there is a Plateau? I got to thinking about Anomaly and came up with this:

      An Anomaly describes how much T has moved from baseline at a point in time, a series of Anomalies, used to describe Daily, Monthly or Yearly Anomaly, describes the sum change of T over the period thus describing rate of change, just as distance is one measurement and multpile measurents that describe a changing distance over a period describe velocity, and multiple measurements that describe changing rate over a period describe acceleration.

      Seems pretty hard to fathom that my suggestions sound reasonable.

      [I guess you mean "don't sound reasonable". I agree that the warming trend over recent meaningful time periods is accelerating, but as usual the denialists are making their counterclaim on a misrepresentative cherry-picked short time period. Their claim can be made, but not defended. - Ben]

  3. Ah yes ‘don’t’. The end result of my proposal is that everybody has been inadvertently ‘hiding the incline’.

    My proposal is based on the rock solid ‘if a year is above average the new average is higher’.

    It’s not just Denialists who are saying Global warming has plateaued, it is Jones, Trenbarth looking for the ‘lost heat’ etc.

    Denialists will bastardise any thing to fit their cause but I think there is something fundamentally wrong when Jones can come out and inadvertantly suggest Average Annual Global Temperature has not been increasing.

    It goes even further when one wonders what ‘lost heat’ Trenberth is looking for, the Average is increasing so why look?

    I think this is all due to interchanging Anomaly with Anomalies, Anomaly is a moment in time and Amomalies is the sum of Anomaly over a period, almost akin to replacing Distance with Velocity, but I colud be wrong, currently debating this on Tamino’s.

    If Anomalies are seen as speed then the lack of significant change in Anomalies over the last 10 years means that warming is occuring with no acceleration, at a constant rate, if this is true then the last few years have been a win for the denialists as the ‘plateau meme’ has been a pervasive spanner in the wheel of reduction.

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