John Christy: Climate Prediction too Uncertain for Policymaking

Posted: February 9, 2014 by tallbloke in Analysis, atmosphere, climate, Clouds, Forecasting, Measurement, Ocean dynamics, Uncertainty

John Christy has been interviewed by ‘Talking about the weather‘:

christyJohn Christy, director of the Earth System Science Center at the University of Alabama-Huntsville.John Christy is a climate scientist at the University of Alabama-Huntsville. Along with Roy Spencer, he developed the first satellite temperature record of the Earth. Skeptical about catastrophic anthropogenic global warming, he has been invited to speak before Congress several times. He is the director of the Earth System Science Center at UAH.

TATW: What would be the single piece of information that you would convey to people who have strong opinions about climate and little knowledge?

CHRISTY: A fundamental aspect of science is that when we scientifically understand a system, we are able to predict how the system evolves in time. The comparison of model output with observations indicates we have much less understanding than what is needed to predict it with any confidence. I certainly don’t see the predictive skill necessary for policy determination.

TATW: Judith Curry spoke to Congress recently; what was the experience like the times that you have done it?

CHRISTY: The experience forces you to think carefully about your testimony because it is going “on the record.” However, sometimes listening to the committee members repeat talking points that border on myths is wearisome.

TATW: Nature’s AGW “pause” story is getting a lot of attention. Do you think that will have been an aberration, or do you anticipate more such discussions coming from climate journals?

CHRISTY: The “pause” is too large to ignore, but can be ignored if the belief system of the writer is threatened by it. It will be addressed more and more. However, the next big El Niño will tip the recent trend to be a bit positive which may cause warming enthusiasts to breathe a little easier.

TATW: Do you ever wish that your branch of science was completely apolitical, or that the public cared about it less?

CHRISTY: I like being in a science that has importance to people. However, the level at which climate science has become the purview of a select authority ( i.e. government agencies or the IPCC) means that alternative views are marginalized in the name of “consensus” rather than presented as options. Such authorities become “gatekeepers” of scientific information rather than “brokers.” In another aspect of my work, we have seen considerable gains in the agriculture productivity of Alabama farmers in part due to our efforts to demonstrate how irrigation can be both environmentally and economically sustainable in a humid state like ours. Having a positive impact on economic development through climate science is quite satisfying.

TATW: What is your perspective on the hidden, deep-ocean heat originally proffered by Kevin Trenberth as the reason for the cessation in atmospheric warming?

CHRISTY: First, measurements are not thorough and precise enough in space and time to determine down to less than 0.01 dec C what the ocean system is doing. So, though it is a legitimate hypothesis to test, it is also extremely difficult to test with any confidence. Secondly, an obvious alternative hypothesis is that the heat never accumulated in the system to begin with, but escaped through many other processes available to the climate system (i.e. cloud processes

  1. ren says:

    A sharp temperature jump at a height of 30 km.

  2. Climatism says:

    Reblogged this on CACA and commented:
    Pleasant to read climate science delivered in an objective, calm, reasoned, rational, non agenda-driven and ‘sceptical’ way.
    Good interview Rog.

  3. oldbrew says:

    Dr Christy produced a slide show covering things like ‘popular weather scare stories’, ‘low impact of increased CO2’, ‘problems with US temperature records’ etc.,linked to here:

    He also submitted written evidence by invitation to US Congress (reproduced in above link) in which he concluded by saying:

    ‘I’ve lived in Africa and can assure you that without energy, life is brutal and short. We are not
    evil people for emitting CO2, we are good people because we recognize the direct and powerful benefits to human life that carbon-based energy supplies. With that I’ll close, thank you.’

    All this is only worth mentioning because there seem to be so few experts able or willing to make sensible public statements about global climate.

  4. Climate Prediction too Uncertain for Policymaking

    It is the case indeed, because several decades are lost in climate science due to uncritical acceptance of questions from policymakers in exchange for funding. This kind of deal is traditionally called “corruption”, which does much harm to both parties in the long run, because there is simply no such thing as the right answer to the wrong question.

    However, I do not think we can never get any meaningful answer to genuine scientific questions. For example we could easily give an indisputable lower bound to inherent uncertainties in the current reductionist computational modelling paradigm by doing a toy project.

    But there is more to it. There are emergent phenomena, neither utilized nor explained yet, like the observed extremely precise match between all sky hemispheric albedoes, while clear sky albedoes are vastly different. Whenever one runs into a symmetry of this kind, it suggests the possibility of a tremendous simplification in theory.

    Journal of Climate, Volume 26, Issue 2 (January 2013)
    The Observed Hemispheric Symmetry in Reflected Shortwave Irradiance
    Aiko Voigt, Bjorn Stevens, Jürgen Bader and Thorsten Mauritsen

    “Climate models generally do not reproduce the observed hemispheric symmetry, which the authors interpret as further evidence that the symmetry is nontrivial.”

    Let science ask its own questions. This way there is at least some hope for policymakers that they will start to get answers, eventually, to their own questions, as mere spinoffs. Almost certainly not the answers they sought, but valid ones.