Pumbaa, with you, everything's gas

Why human CO2 emission can't explain observed variations in the weather.

THERE HAVE BEEN many successful energy transitions in human history. In each instance—wood to whale oil, whale oil to hydrocarbon, hydrocarbon to nuclear—the transition has been from a lower to a higher level of energy-per-person.

There are no examples in history that we know about of a successful transition from a higher to a lower level of energy-per-person. None have been voluntary, and each has been accompanied by a mass casualty event driven by cold, starvation, disease, and violence.

“Net Zero” is the first attempt in human history to voluntarily transition from a higher to a lower level of energy-per-person. It is extraordinarily reckless.

The supposed justification for this extraordinarily reckless ideology is the notion that CO2 is a toxin. The origin of this notion is in liberal authoritarian politics of the 1970s. They realised that they will never be able to gain the control of our freedoms that their ideology needs by direct means. So they made a genius move. CO2 is the byproduct of almost every human economic process that generates wealth. Control CO2, and you control all human economic processes. Restricting CO2 would be like sticking a banana in economic freedom’s tailpipe. An obscure hypothesis, regarded as highly eccentric at the time—that human CO2 emissions possessed the power to wipe out life on the planet—was elevated to the status of “settled science” and, well, here we are.

Destroy the hypothesis that CO2 is bad, and you destroy the rationale for Net Zero. In this week’s essay, I thought I might share with you a reply I gave recently on Twitter/X to someone who invited me to explain the irrelevance of CO2 to our energy policies. I’ll quote it with minor corrections for readability—my interlocutor is a scientist so the argument is a little abbreviated, but the gist should be clear enough.

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Please tell me: what data convinced you that CO2 is a minor forcing factor?

Sure. To clarify—your hypothesis isn't that climate is changing. This is a trivial observation. Your hypothesis is that humans are changing the climate via CO2. My observation is that human CO2 emission is a minor climate forcing function relative to all others, including natural CO2 emission, and that the variability of other candidate explanatory factors precludes the claim that only human CO2 emission can account for observed variation in the weather with sufficient confidence to justify the extraordinarily dangerous political program it has been created to support.

Schmidt (2010) estimates that CO2 contributes about 20% of the GHG effect. Humans contribute around 5% of gross natural annual CO2 emissions. So humans increase the natural production of a minor greenhouse gas by about 1% annually. In isolation, that 1% (around 1.5% after accounting for change in stock rather than annual flow) produces a beneficial warming effect.

However. This warming effect is combined with a large number of other processes that also alter CO2. Other GHG forcing functions similarly exhibit natural variation. And the GHG forcing function is in turn combined with other forcing functions. Many of these functions are periodic, with periods measured in years, decades, centuries and (as fas as we know) millennia—with the latter being the period relevant to the study of climate change, as distinct from weather change. Many climate forcing functions individually exhibit variability comparable with human emission and, when in phase with others, greatly exceed it both positively and negatively.

All of this takes place within a system that has a number of positive and negative feedback systems. The negative feedback systems—e.g. meridional transport—further moderate the effective contribution of human CO2 as a climate forcing function. We have good reason to suppose that the negative feedback processes dominate, from the simple observation that we are here despite the existence in the paleoclimate record of multiple events in the previous million years that ought to have triggered supposed positive feedbacks and have not.

So I find your hypothesis—that observed variation in weather can, and can only, be explained in terms of human CO2 emission and that, to the extent that this produces warming, this warming is to be prevented—to be unbelievable.

I observe that most predictions produced by this hypothesis that are distinct to it, rather than general observations of the weather as we emerge from a recent ice age, are wrong and that the IPCC in its latest scientific report (as distinct from its political report) finds no connection between human activity and any of the adverse weather phenomena predicted by your hypothesis with the exception of some warming and cooling.

And finally. I find the ideology that your hypothesis is intended to support—the detransition of human civilisation to lower energy per capita energy levels—to be extraordinarily dangerous. Such an extraordinary demand requires extraordinary evidence. And after all of the objections to legitimate criticism of the climate catastrophe hypothesis have been made, one thing will remain true: there is no extraordinary evidence for it.

—ENDS—

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