Climate Models

They seem to be modeling some other planet:

Christy compared the outputs for the tropical troposphere of 73 models used by the IPCC in its latest report with satellite and weather balloon temperature trends since 1979. “The tropics is so important,” Christy explains in an email message, “because that is where models show the clearest and most distinct signal of greenhouse warming-so that is where the comparison should be made (rather than say for temperatures in North Dakota). Plus, the key cloud and water vapor feedback processes occur in the tropics.”

When it comes to simulating the atmospheric temperature trends of the last 35 years, Christy found, all of the IPCC models are running hotter than the actual climate. The IPCC report admits that “most, though not all, of [the climate models] overestimate the observed warming trend in the tropical troposphere during the satellite period 1979-2012.” To defend himself against any accusations of cherry-picking his data, Christy notes that his “comparisons start in 1979, so these are 35-year time series comparisons”-rather longer than the 15-year periods whose importance the IPCC downplays.

Why the discrepancy between the IPCC and Christy? As Georgia Tech climatologist Judith Curry notes, data don’t speak for themselves; researchers have to put them into a context. And your choice of context-say, the year you choose to begin with-can influence your conclusions considerably. While there may be nothing technically wrong with the way the IPCC chose to display its comparison between model data and observation data, Curry observes, “it will mislead the public to infer that climate models are better than we thought.” She adds, “What is wrong is the failure of the IPCC to note the failure of nearly all climate model simulations to reproduce a pause of 15-plus years.”

There is too much that they don’t, and at least for now, can’t capture. And it would be economically insane to base policy on them.

12 thoughts on “Climate Models”

  1. You appear to denounce climatology as “un-scientific” and unworthy of influencing the policy makers,
    while “Accepting” economics as “science” and that the conclusions of economists should be taken as gospel.

    Economics is not a science, but more the social psychology of people with money.
    It seems odd that you give economists respect they don’t earn or deserve, while you denounce
    climate scientists as a whole.

    1. To compare CAGW and economics more accurately, it’s like claiming that Marxism is “scientific” economics and denouncing all forms of capitalism as “unscientific”, then denouncing capitalists as saboteurs, profiteers, and conspirators.

      The problem with climate models is that they don’t work, as is apparent by how the world’s temperature fell through the bottom end of ALL the model runs used by the IPCC. Since observed reality is not within the range of model projections, the models have failed. For all the models to fail so spectacularly means the models are wrong, and should be seriously revised or entirely rejected. That’s the way science is supposed to work, and largely does work in other fields of study.

      As engineers, we model things quite often, and one of the requirements of modeling is to accurately understand the inputs and relations – ie. the data and the equations that describe the system we’re modeling. So if we’re trying to model the performance of an aircraft, we’d use L=1/2*rho*area*CL * V^2, then punch in the formula for induced drag, parasitic drag, and all sorts of other parameters, and get a reasonable approximation of how the aircraft will perform, The problem with climate modeling is that they’re doing it before they know the formulas, which means the results are essentially wild speculation.

      In terms of the physical models themselves, they make a few simplifications. Among these are that gravity is constant, instead of diminishing with Newton’s square law of attraction. Another is that the surface area of a sphere is independent of radius (in several forms). Another is that momentum is not conserved when no external force is applied. Air that moves upward accelerates horizontally, just because it does! And of course, evaporation and condensation don’t really occur, because Navier-Stokes equations can’t deal with them.

      So the models aren’t really based on physics, except perhaps Aristotle’s physics, and aren’t even in agreement with Euclidean geometry. They’re a pile of patches to make the calculations tenable and ignore all the parts we don’t understand or that would be too computation intensive to run. So their outputs come down to whatever amplification factor was input as the key variable, and that number is just a guess.

      1. Even worse than that, what are the criteria used for judging whether a climate model has too many free parameters? What are the criteria using for judging the accuracy of a climate model?

        Climatology is an interesting and promising field, but it is in a very immature state today and incapable of modeling the Earth’s climate to any degree of accuracy over any substantial period of time.

        1. It’s okay to question the models, but the backwards looking
          geo-climatology sure doesn’t look good.

          Wether it’s the last 200 years of weather data, or
          200,000 years of Paleo-climate data, it sure isn’t
          a positive looking thing.

    2. When your model (any model, be it climate, economics, whatever) doesn’t reflect with reality, it isn’t reality that’s wrong. When none of your models reflect with reality, it means you don’t understand the domain you’re attempting to model. If the models don’t reflect reality as it happens, they’re completely useless at making predictions for what will likely happen in the future. You’d be about as well off using a Magic 8 Ball.

      1. Economics is built heavily on models, with lots of crappy assumptions in them,
        yet people believe them all the time. The Supply-Side models said Deficits wouldn’t
        increase under Reagan or Bush Jr. Didn’t happen that way.

        1. You are so off base
          here, I don’t even know where
          to start.

          ” The Supply-Side models said Deficits wouldn’t
          increase under Reagan or Bush Jr.”

          Deficits don’t go down when spending increases more than additional revenue generated by taxation policies. But why limit talk of deficits to only Republicans? Wouldn’t the deficits and debt racked up by Obama invalidate his economic theology if your standards were applied equally?

          The amazing thing is that you are defending the field of climate science by saying that it isn’t any worse than economics which you hold in disdain.

          dn-guy: “I hate economists. Their entire field is a bunch of hocus pocus on par with climate science.”

    3. “Economics is not a science, but more the social psychology of people with money.”

      Wrongo-bongo (again).

      Economics is the study of optimal allocation of scarce (finite) resources. You can have economics without money.

      For example, if the number of doctors on a battlefield after battle or at a disaster site are insufficient to treat everyone fairly quickly, the doctors (the finite resource) will practice triage ( optimal allocation ). That’s economics.

      You really need to read something other than the Communist Manifesto, Huff Po and comic books.

    1. You have to respect the Drake Equation, whose mathematical basis is unchallenged. I use a variant of it to calculate the odds that on any given night I’ll hook up with a hot NFL bisexual-curious cheerleader who is allergic to peanuts and battling the early stages of alcoholism and rampant sex addiction, yet whose OCD compels her to bake me walnut chocolate chip cookies and scrub my floor as I sip cocoa in my footy pajamas and talk to her about the benefits of Obamacare.

      It’s SCIENCE.

      1. Wow, you know Bree?!? Or maybe you mean Marissa. That could also be Ashley, come to think of it. They’re a blur to me, especially when I’m with all three at once…

  2. “The tropics is so important,” Christy explains in an email message, “because that is where models show the clearest and most distinct signal of greenhouse warming-so that is where the comparison should be made (rather than say for temperatures in North Dakota). Plus, the key cloud and water vapor feedback processes occur in the tropics.”

    No offense, but upper latitudes show the strongest signal because that causes a shift in snow cover. While the radiation law (that heat radiation is the fourth power of temperature) means that the high temperature tropics are going to show a somewhat lower increase in temperature increase.

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