Climate Feedback Faux Pas

We are constantly bombarded with information from various warmer oriented entities concerning “positive feedbacks” and “forcings” and how they relate to claimed anthropogenic global warming. They usually seem to arrive at the conclusion we will heat up and die unless we take their word for it and institute draconian and expensive measures to reduce our CO2 output.

Dr. Roy W. Spencer and William D. Braswell have a paper published at the Science and Public Policy Institute (SPPI) titled “On the Diagnosis of Radiative Feedback in the Presence of Unknown Radiative Forcing” (PDF) that disputes the ability to utilize satellite data to arrive at any meaningful conclusions about global warming concerning radiative feedbacks and radiative forcings.

According to them it’s apparent some scientists must have a magic technique that allows them to arrive at claimed conclusions about radiative feedbacks and radiative forcings causing global warming. Why? Because per this paper it cannot be done. (Note: The paper doesn’t even delve into the accuracy of that satellite data which is questioned here, here, here, here, here, and here).

They arrive at the following conclusions about claims being put forth in a desperate effort to prove that global warming is real.

6. Discussion and Conclusions

[56] Previous attempts to diagnose radiative feedback in the climate system from the covariations between TOA radiative flux and temperature have yielded generally low correlations and a wide variety of feedback estimates. The evidence presented here (from satellite, a simple forcing‐feedback model,and from coupled climate models) suggests that the dominant source of that decorrelation is the presence of time‐varying radiative forcing generated internal to the climate system.

[57] While some might object to the term “internal radiative forcing,” it accurately describes both the origin and mechanism of operation within the forcing‐feedback construct of climate variability. Any radiative variability that is not due to feedback must be due to forcing. And the alternative term“internal climate variability” does not distinguish between the two different kinds of forcing of temperature change that occur: radiative and nonradiative. The most likely mechanism for this internal radiative forcing is nonfeedback fluctuations in low clouds, although nonfeedback variations in water vapor or high clouds might be a significant component of the decorrelated portion of the LW variations.

[58] It has been demonstrated that radiative feedback in response to unknown levels of time‐varying radiative forcing is, for all practical purposes, not observable. This is because the feedback signal is mostly masked by the radiative forcing itself. A simple forcing‐feedback climate model, as well as the IPCC AR4 coupled climate models, reveals that quasirandomtime‐varying internal radiative forcing results in spiral patterns in phase space plots of low‐pass filtered temperature and radiative flux variations, patterns which obscure the signature of feedback. Feedback can only be clearly observed in response to nonradiative forcing of temperature,in which case linear striations appear having slopes approximately equal to the feedbacks operating in the models. These striations are believed to only appear during periods when nonradiative forcing is relatively large at the same time that any radiative forcing is relatively constant.

[59] In the AR4 coupled climate models, these striations are obvious in only four models, and then only in the LW, not SW, component. In these four models, the striations lie roughly parallel to the long‐term feedbacks previously diagnosed from the models by Forster and Taylor [2006].While supportive of our physical interpretation based upon the simple model experiments, it is premature to claim that the linear striations seen in this handful of AR4 models means that the short‐term and long‐term feedbacks in the climate system are substantially the same, especially since we could find no obvious linear striations in the SW variations in the AR4 models. The general lack of these feedback signatures in the AR4 models could be due to the relatively weak levels of intraseasonal fluctuations in moist convective activity, for instance the Madden‐Julian oscillation [Lin et al., 2006], in the coupled climate models.

[60] Striations in 9 years of global average CERES radiative fluxes from the Terra satellite have a slope around 6 Wm−2 K−1 in net (LW + SW) radiative flux variability. This is similar to the feedbacks diagnosed by Lindzen and Choi [2009] from interannual variability in recently recalibrated Earth Radiation Budget Satellite data, as well as that diagnosed for a composite of 15 strong tropical intraseasonal oscillations analyzed by Spencer et al. [2007]. Although these feedback parameter estimates are all similar in magnitude,even if they do represent feedback operating on intraseasonal to interannual time scales, it is not obvious how they relate tolong‐term climate sensitivity.

[61] Further complicating the diagnosis of feedback from satellite data is the different relationship that radiative flux variations have to surface temperature versus tropospheric temperature on short (intraseasonal) time scales. During nonradiatively forced temperature fluctuations, the signature of feedback is most clearly revealed in response to tropospheric,rather than surface, temperature. Since feedback is traditionally referenced to surface temperature, extra caution must therefore be taken in the physical interpretation of any regression relationships that TOA radiative fluxes have to surface temperature variations.

[62] It also underscores a practical limitation that, since the climate system is never in equilibrium, feedbacks in the climate system cannot be diagnosed from differences between equilibrium climate states. Time‐varying radiative and nonradiative forcings are continually occurring, and so radiative feedback parameters will need to be diagnosed in the presence of some level of time‐varying radiative forcing, which we have seen usually leads to large errors.

[63] It is clear that the accurate diagnosis of short‐termfeedbacks (let alone long‐term climate sensitivity) from observations of natural fluctuations in the climate system is far from a solved problem. As we have seen, the presence of nonfeedback, internally generated radiative forcing confounds the identification of radiative feedback. Nevertheless,it is hoped that the insights provided here, all explained within the forcing‐feedback paradigm of climate variability, will lead to new and more accurate methods of feedback and climate sensitivity diagnosis from satellite observations, as well as better metrics for the testing the climate sensitivity of coupled climate models..

You can read the whole paper  here (PDF) and arrive at your own conclusions. I’d suggest that next time you read about some of  those “positive feedbacks” that are causing global warming remember that contrary to warmer claims, the science is far from settled.

As of now claims being made about radiative forcings and feedbacks that prove global warming are faux science and are merely more CO2 Insanity.

Source: SPPI


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