I think there is a logical falacy in your last statement

Nope. If there is, then point to it. [Oh, but there is a spelling error in your last statement.]

To explain that some of the longwave infrared radiation leaving the ground being returned, or water vapor equalizing lower tropospheric temperatures at spot A or spot B as “feedback” is a different thing.

But like with LTE, the scope of the issue being understood is the main thing; what are the spatial and temporal characteristics, the conditions we are operating under. Including the unspoken assumptions and such.

I am not of the opinion that using the word “feedback” to describe some output of a system influencing the system to keep it at some type of equilibrium or moving it away from such is confusing or sneaky.

The real question is; if SE almost always passes, and SEM almost always fails, does it matter which you use?

Mark,

Such “originality” would make quite an item in anyone’s CV!

On a more serious note, GCMs have a long history of chronic problems in keeping their outputs bounded when run on climatic time-scales. While some of the problems are traceable to numerical instabilities in iterative Navier-Stokes solutions on a coarse global grid, these affect merely the transport of heat. The fig leaf of chaos cannot hide the ubiquitous discontinuities of model temperatures at the surface-atmosphere interface or global accumulations of energy (positive Lyapunov exponents) under steady-state inputs and invariant response characteristics. These persistent problems arise from the systematic imbalance of power fluxes attributed to moist convection/precipitation and to downward IR. (Assumptions of fixed relative humidity are egregiously unrealistic.) In other words, the models are not cohesive energy-conserving systems. All sorts of ad hoc procedures are used to rein in outputs, but the problem has not been solved at its root.

While I’m attuned to the skeptical rationalist thread that runs from Kant to Popper, the empirical/pragmatic views of John S. Mill and Charles S. Peirce to problems of scientific inference cannot be ignored in bona fide climatology. Alas, with boundless fanciful attributions to AGW, what we are witnessing is a philosophy which stems from roots of shamanism.

Just as the S/N ratio of the discussion finally rises well above unity (thanks to your and some of Sam Urbinto’s contributions), I’m regrettably forced to abandon it in order to prepare for a project overseas.

I saw the opportunity to make a bad Hume related pun and it turned into three comments:

1. Public Utility vandals increase Public Utility. (kim– a little help?)

2. Popper salvaged the scientific method from Hume’s attacks on induction but agreed that the problem of causation did not have a positive solution, what caused the cause is not really on the table. I have not kept up with literature– perhaps a lurking Bayesian Philosopher or Statistician could provide homework to bring us up to speed on the development of p(h/e|c).

3. Skimming Hansen’s testimony and considering the outcome it is hard to believe that Hansen’s methods and tools are objective and independent of personal views– I am sure that early in his career this was not the case. By all appearances, in the latter years of his career, the authority of his science rest on a social foundation rather than an objective one. Kuhn had much to say on this. Feyerabend even more. Popper would, I assume, be appalled at the notion of a consensus confirming anything. Brining us back to my #1– How then to calculate the probability of a high value for the public utility of public utility vandalism?

“no physical system can operate on future forcings or change the past” to be a “personal theory.” That would be flatering me beyond all reason.

Hehe, wouldn’t you love to be credited with the principle of causality, eh John S.?

I actually argued with a guy regarding this once. He was a philosophy major entranced by Hume’s works. I suppose folks like that come from the “what causes the causes” viewpoint.

Mark

Mark

Sam,

Sorry for missing your latest before I posted. I, too, despise pedantry. But I also hate analytic confusion getting in the way of progress in science–or understanding between gentlemen.

Gotta attend to other matters! I won’t be on this thread for a while.

Steve,

In his testimony, Hansen talks system science talk, but fails to walk its demanding walk. Discussion of this disconnect seems very much on-topic.

System analysis rests on rigorous mathematical foundations presented by Norbert Wiener in his seminal book The Fourier Integral and Certain of Its Applications (1933) and expanded upon in Cybernetics (1948). (Because of the color of its covers and its mathematical demands, the former tract was called the “yellow peril” by students of the post-war generation.) Properly applied in many fields of science, the analytical techniques have a spotless track-record of performance, as the mountainous literature attests. Misapplied, they lead to conceptual confusion and unreliable results presented under the color of authority.

By patently ignoring the fundamental requirement for realizable (i.e., causal) systems and imputing non-existent feedbacks, Hansen & Co. often posit unsupported explanations of the climate system that are little more than climatespeak. System realizability is quite intimately connected to the principle of irreversibility in thermodynamics. I hope you don’t consider my (#218) statement that “no physical system can operate on future forcings or change the past” to be a “personal theory.” That would be flattering me beyond all reason.

The definition you quoted is oriented toward control systems. They have output-sensors which activate external power sources to alter the input in order for the output to conform to a desired result. While biological systems, which may have positive feedback between various subsystems (with on/off switches to bound the response), are often control systems, energy-conserving natural systems don’t operate that way.

Ludicrous as it may sound to you, a rigorous system model of the effect upon surface temperatures from albedo changes due to snow/ice ablation will not have any feedback loop whatsoever back to the fundamental input of insolation. (There are other inputs, of course, but they all draw their power from insolation). And that is as it should be, because the insolation signal remains unaffected. What does change is the system characteristic, which determines the instantaneous response to the input. (One would expect to see a huge accelleration in that nonlinear characteristic around zero C.) Such a system is properly called time-varying. Modeling it becomes much more complicated, but miscasting it as a feedback system would yield grossly misleading results.

Hope this clarifies what I’ve been saying all along.