Does the Climate System Have a Preferred Average State? Chaos and the Forcing-Feedback Paradigm

[Elderberry]

Dr. Roy Spencer.com October 25th, 2019

NOTE: I have written on this subject before, but it is important enough that we need to keep thinking about it. It is also related to the forcing-feedback paradigm of climate change, which I usually defend — but which I will here take a skeptical view toward in the context of long-term climate change.

The UN IPCC scientists who write the reports which guide international energy policy on fossil fuel use operate under the assumption that the climate system has a preferred, natural and constant average state which is only deviated from through the meddling of humans. They construct their climate models so that the models do not produce any warming or cooling unless they are forced to through increasing anthropogenic greenhouse gases, aerosols, or volcanic eruptions.

This imposed behavior of their “control runs” is admittedly necessary because various physical processes in the models are not known well enough from observations and first principles, and so the models must be tinkered with until they produce what might be considered to be the “null hypothesis” behavior, which in their worldview means no long-term warming or cooling.

What I’d like to discuss here is NOT whether there are other ‘external’ forcing agents of climate change, such as the sun. That is a valuable discussion, but not what I’m going to address. I’d like to address the question of whether there really is an average state that the climate system is constantly re-adjusting itself toward, even if it is constantly nudged in different directions by the sun.

If there is such a preferred average state, then the forcing-feedback paradigm of climate change is valid. In that system of thought, any departure of the global average temperature from the Nature-preferred state is resisted by radiative “feedback”, that is, changes in the radiative energy balance of the Earth in response to the too-warm or too-cool conditions. Those radiative changes would constantly be pushing the system back to its preferred temperature state.

But what if there isn’t only one preferred state?

More: http://www.drroyspencer.com/2019/10/does-the-climate-system-have-a-preferred-average-state-chaos-and-the-forcing-feedback-paradigm/

[Bigun]

Dr. Spencer asks some very important questions and makes some very good points in this article. I hope everyone here reads it.