Guest essay by Ronald D. Voisin
Let’s examine, at a high and salient level, the positive-feedback Anthropogenic Global Warming, Green-House-Gas Heating Effect (AGW-GHGHE) with its supposed pivotal role for CO2. The thinking is that a small increase in atmospheric CO2 will trigger a large increase in atmospheric Green-House-Gas water vapor. And then the combination of these two enhanced atmospheric constituents will lead to run-away, or at least appreciable and unprecedented – often characterized as catastrophic – global warming.
This theory relies entirely on a powerful positive-feedback and overriding (pivotal) role for CO2. It further assumes that rising atmospheric CO2 is largely or even entirely anthropogenic. Both of these points are individually and fundamentally required at the basis of alarm. Yet neither of them is in evidence whatsoever. And neither of them is even remotely true. CO2 is not only “not pivotal” but it is not even clear that atmospheric CO2 influences climate in the least measurable way. And the current spike in atmospheric CO2 is clearly not primarily human caused. Factually, atmospheric CO2 cannot be beneficially changed by human behavior, regardless of what actions we might take. And climate will always continue to change in significant ways that will most likely be poorly predicted.
Nonetheless both these points, 1) atmospheric CO2 pivotally controls climate; and 2) we pivotally control atmospheric CO2, are hard-wired into all General Circulation Models of the climate – Models that attempt to predict the far future behavior of a “coupled, non-linear chaotic system”. One is compelled to consider that this modeling effort may well, in fact, be impossible. Yet these Models constitute substantially the entire evidentiary basis for Anthropogenic Global Warming (AGW) as opposed to non-anthropogenic global warming (NGW or Natural Global Warming) for which there is a great deal of evidence. There is only one place anywhere in the history of the world where a CO2 increase precedes a temperature increase and that is in the Models themselves. And while extraordinary claims require extraordinary evidence, after 20+ years and with 10’s-100’s of Billions of global $’s devoted to this issue, the situation is unchanged. Where is the evidence of CO2’s pivotal feedback? And how can you justify a continued belief that rising atmospheric CO2 is entirely or even largely anthropogenic? The most vocal proponents of AGW-GHGHE theory are reduced to literally ask: “How else do you explain it?” But that is not evidence. And, far more importantly, it is also not clear what needs to be explained. See Figure 1.
First, let me make the (actually) profound point that this Earth has gone through 60-70 known major climate transitions over many hundreds, even thousands, of millions of years. It did so while maintaining an exceptionally narrow thermal range (~+/- 6-10OC) throughout all this history. This incredibly tightly controlled, long duration behavior can only be understood in the context of a system overwhelmingly dominated by negative-feedbacks. At an entirely fundamental level this assertion has to be true and profoundly so. However, these negative-feedbacks are poorly represented in our current Modeling efforts and their investigation is underfunded to the point of being ignored.
Further, the ice-core analysis makes clear the relative timing of events. And while it is certain that atmospheric CO2 lags temperature in both directions, so as to more readily be an effect and not a cause of temperature change, the one fact that is most uncertain from ice-core analysis is the exact magnitude of the CO2 spike that accompanies each and every interglacial (and also accompanies warming periods within a given interglacial).
Why? Because, for one, these spikes are, by definition, the highest temporal frequency events – which, of course, bestow on them the greatest sampling uncertainty. But this uncertainty is of magnitude and not of relative timing. The CO2 peaks, as represented from the ice-cores, are the established values obtainable within a finite (and limited) temporal sampling resolution. If higher sampling resolution could be arbitrarily applied, it could only reveal yet higher peaks (i.e. yet higher frequency events). These are facts of statistical sampling (we are fortunate to get 500 years least-count time resolution on any parameter when we go back more than just a few 1000’s of years).
Additionally, this uncertainty of magnitude is further muddied by an incomplete understanding of diffusion processes taking place distributed within an enormous pressure gradient (along with many other poorly understood processes). The uncertainty of this diffusion between ice layers can only act in such a way so as to underestimate the peaks of the highest frequency components as these peaks are also exactly, and by definition, where the diffusion gradient too is the very greatest. (There is no method to recover this lost information as it is no longer present within the samples.)
Therefore an exceptionally important aspect regarding the ice-core analysis, and one that is seemingly wholly under-appreciated, is the fact that this uncertainty of magnitude is substantially (entirely) all in one direction. And that direction is up. The highest peaks (ones that might have durations of only several hundred years) would not be temporally resolved at the very same time that unquantifiable diffusion processes would attenuate them preferentially the greatest (and with most likely significant attenuation as the higher and sharper the peak the more and harder our post-dated analysis will knock it down). Therefore in the end, we do know with certainty that CO2 lags temperature. But for all we know, atmospheric CO2 has spiked to over 1000 ppm (not so unlikely), for a relatively short period of time (quite possibly up to 500 years or even more), during each and every prior interglacial (and to only a marginally lesser extent in prior warming periods of the current interglacial).
Let me state this again, differently, and with as much clarity as is possible. All of the ice-core data, each and every piece, without regard to where the analysis might fall within the spatial extent of the physical ice core sample, supports the relative timing of temperature vs. CO2. And CO2 lags temperature without doubt. However, when it comes to the highest frequency components (the CO2 peaks) we can say with certainty that they are under-represented in the analysis. The true reality of the peaks of CO2 is that they are higher than we have determined, but by an amount higher that we cannot determine. And I would dare to add that prior peaks were very likely >>600 ppm.
See Figure 2.
Next…we then know that every warming period has an attendant, but delayed, atmospheric CO2 spike. And most likely, the currently observed spike is but a fraction of what has occurred in every prior warming period and therefore most likely, but a fraction of what it is to become in this one – and, quite presumably, for the same natural causes of all prior events. So, why it is that some insist that the currently observed atmospheric CO2 spike is anomalous, or anthropogenically dominated, is entirely unclear.
Figure 3 outlines the primary sources of natural CO2 release in decreasing order of quantity of carbon emitted: oceanic release, microbial decay, insect activity, frozen terrestrial release; volcanic release; forest fire and then mammalia exhalations and emissions – summing to a total of ~325-485 petagrams. Then there is our ~2.0% anthropogenic release at ~8-9 petagrams. (Based on terrestrial sources alone, without oceans, anthropogenic release is ~3-4% of the natural flux. Some argue that the oceans are net absorbers and ignore the oceanic release estimate below. However, according to the hypothesis presented herein the oceans are net emitters as indicated below when warmed by ~0.5oC per century).
These natural sources all correlate to global temperature (including, at the least, terrestrial volcanism, as recently verified). When the Earth gets warm, for whatever reason, these natural sources all kick-in together to contribute vast quantities of CO2; and to produce the observed habitual atmospheric CO2 spikes upward. Conversely, when the Earth gets cold, for whatever reason, they all go into remission together; naturally and (generally) coherently to produce a consequential reduction in atmospheric CO2. Each spike or dip in CO2 follows temperature with a lag time averaging 800 years, but proportional to the level and magnitude at which the temperature swings take place.
It is extraordinarily difficult to imagine that these natural sources are not at play during this current period of warming. They most likely are the primary cause of the currently observed CO2 spike. And yes, we humans, as co-inhabitants of this Earth, are emitting CO2. But so are microbes and insects emitting. And each of them is emitting with ~10 times our current anthropogenic emission. In both cases (microbes and insects) there is every reason to believe that their populations are geometrically exploding in this current highly favorable environment to their existence. The recently warming oceans are most likely the largest emitter of all. Atmospheric CO2 is spiking just now. And we have good reason to believe that it is largely, essentially entirely doing so for all the same reasons it has done so within each and every prior warming period of the past. All natural sources of CO2 emission are currently revved-up and in high gear during this extended interglacial. Approximately 98% of the current spike is natural while we add our anthropogenic 2%.
We also have reason to believe that the current spike would be as large, or larger, than now observed, if we humans were never here at all. Why? Because those organisms that would otherwise be here in our stead would most likely emit much more CO2 than we are. i.e. We humans have chosen to systematically limit the proliferation of micro-organisms and insects in the land we use for cultivation and occupation – which represents about 1/3rd of all land. And in the other 2/3rds of all land, microbes and insects are each estimated to emit ~10 times our anthropogenic emission (insects alone outnumber humans >>10,000,000,000:1 – enough to fill several large dumpsters per person).
The relative contribution from microbe and insect emissions would have gone up significantly if we were never here (by a very rough factor of up to 1.5*). They would have filled our void geometrically; unlike our anthropogenic contribution. When we humans get rich, we uniquely self-limit our proliferation, by deciding to have fewer children. And our human emission pales in comparison to the emission from these astronomically vast numbers of other organisms. So if we were never here, greatly enhanced populations of microbes and insects would be emitting many times our anthropogenic emission from the very land that we systematically exclude them from. This situation most likely characterizes the events within prior interglacials.
To put some rough figures on this: current microbial and insect emissions are estimated at ~160 petagrams. If we were never here our 8-9 petagram anthropogenic emission would go away – but only to be replaced by an increase of up to 80 petagrams of additional contribution from microbes and insects. The current spike would then be larger than now observed. And again, this situation most likely characterizes the events within prior interglacials.
*Certainly our limitation to the proliferation of microbes and insects has not been 100% within the lands we cultivate and occupy. However, this limitation need only be an easily accepted value of ~10% or greater for the assertion to be true: we have reason to believe that the current spike would be as large, or larger, than now observed, if we humans were never here at all. i.e. Humanity’s “carbon footprint” is a net negative contribution.
And, yes it is so, that our anthropogenic release is largely made of “long-time” sequestered carbon (unlike that of much microbe and insect emission). But the term “long-time” is quite relative. It is certainly a long-time sequestration by our understanding of human existence. However it is not so long at all on a geologic timescale. Massive-scale natural release of “long-time” sequestered carbon has littered this Earth’s geologic past (and continues today). Some seem to think that this sequestered carbon is so thinly scattered as to be quite rare. This might lead you to believe that it is geologically a one-way function such that this carbon, in many forms such as fossil fuel, is mostly sequestered and rarely, if ever, naturally released (to some great benefit of climate). But the truth is that “long-time” sequestered carbon is ubiquitous by nature, dominates natural release sources, and is often cataclysmically released on very large scales through many natural processes (such as thawing tundra, volcanic and super-volcanic eruption).
There is little reason to believe that our current 2%-of-flux release of “long-time” sequestered carbon is consequential by any geologic standard of the past. Natural processes have surely produced many periods of hundreds of years of sequestered carbon release, wherein each year provided multiple percentage points addition to the just prior natural flux trend. In fact, anthropogenic release is not only very small when compared to the magnitude, but more importantly, the variability of natural release (the significant point here being that the notion of a steady-state 1:1 pairing of natural CO2 sources and sinks is wholly unjustified when natural release events regularly produce huge and large-scale, long-duration disruptions). And keep in mind that approximately 50% of natural, steady-state CO2 release is of “long-time” sequestered carbon while essentially 100% of cataclysmically released carbon is of the “long-time” sequestered variety. Our use of fossil fuels is most likely irrelevant to climate, geologically minuscule and completely lost in the noise of geologic events.
Separately, we know geologically of extended epochs where atmospheric CO2 was many times higher than today’s value (by >10X). But we know of no tipping point in all of Earth’s history (and such an event could not go unnoticed geologically). Epochs where enormously elevated atmospheric CO2 was falling while the Earth warmed to an interglacial. Epochs where enormously elevated atmospheric CO2 was rising while the Earth cooled to glaciation. These facts fly directly in the face of CO2 playing a pivotal role in climate change. In fact they suggest a minor to insignificant role for atmospheric CO2 as regards climate (while they clearly implicate some other truly-pivotal driver).
If we now turn to the supposed positive-feedback and pivotal role of CO2 we have great difficulty notwithstanding the forgoing. During each and every one of the past 60-70 known interglacials we know that atmospheric CO2 spiked. Why didn’t that spiking lead to large increases in atmospheric water vapor? Why didn’t the two of these enhanced atmospheric constituents lead to significant further warming? And then that additional warming would directly lead to yet more CO2 and more water vapor; which would lead to yet more warming, and then more CO2 and more water vapor? Why wasn’t there thermal runaway in each, or any, prior interglacial (as is now feared for this interglacial)? We know that the Earth has never experienced thermal runaway (a tipping point). The likely answer is that the theory of pivotal positive-feedback CO2 may be just plain wrong.
And if CO2 somehow did play a pivotal positive-feedback role in getting to this warm state (which it most likely did not), then how would the Earth ever subsequently and suddenly transit to glaciation (as it has and does) from this latched-up positive-feedback warm state without invoking a yet vastly more powerful and unidentified climate driver?
The very same problem exists in the reverse. When the Earth is glaciated atmospheric CO2 falls, and so does water vapor. Why didn’t the minimization of these two atmospheric constituents lead to significant further cooling? And then to yet lower atmospheric CO2 and water? And then more cooling? Why didn’t the Earth fully ice-over? Why didn’t the ocean depths freeze solid? They never have. The likely answer is that the theory of pivotal positive-feedback CO2 may be just plain wrong.
And again, if CO2 did somehow play a pivotal positive-feedback role in getting to this cold state (which it most likely did not), then how would the Earth ever subsequently and suddenly transit to interglacial (as it has and does) from this latched-up positive-feedback cold state without invoking a yet vastly more powerful and unidentified climate driver?
In another way of asking these questions, how does pivotal positive-feedback CO2 play a role in the major climate transitions? When the Earth is glaciated and atmospheric CO2 is low, what massive CO2 release event accounts for the transition to interglacial? (Recognizing that the tiny radiative perturbations of Milankovitch cycles have been relegated to small amplitude variation at frequencies that are only poorly correlated to climate swings generally, but may nonetheless correlate to major swings in ways speculated herein.) The only possibility is large scale volcanism. But volcanoes are very messy and leave lots of geologic evidence. And we know that that these glacial-to-interglacial transitions are not correlated to preceding major volcanic events. We know that enhanced atmospheric CO2 only arrives, on average, 800 years after the glacial-to-interglacial transition (from natural sources that are consequentially stimulated by the warming). Spiking CO2 is most likely the effect and not the cause.
Similarly, when the Earth is warm and atmospheric CO2 is high, what sudden massive CO2 sequestering event accounts for the transition to glaciation? There is little opportunity here to even investigate another possibility as there are few massive-scale sequestering phenomena, other than oceanic absorption. And the cooling oceans do absorb. But only, on average, 800 years after the climate transition to glaciation (owing to their thermal mass). Again, falling CO2 is most likely the effect and not the cause.
Then there is the most recently observed global temperature and atmospheric CO2 trends. Since 1998 our anthropogenic CO2 emission has skyrocketed (still at ~2% as all natural sources are also just now spiking). But global temperatures are flat to down. It simply cannot be so that pivotal positive-feedback CO2 is at work here. These present-day observations directly conflict with this theory. Something else drives climate change while CO2 is the effect of that change and not the cause.
In the end, it is most safe to say that we simply do not yet know the driver(s) of major climate change. And there is no evidence for a pivotal position regarding CO2. It is not even clear that CO2 plays a tertiary role let alone a primary one. And, most likely, atmospheric CO2 plays no meaningful role at all as regards instigating or amplifying climate change (at <200ppm all life would slowly become crippled; yet CO2’s GHG effect is ~95% saturated at this level).
Some have a difficult time with the idea that anthropogenic emission is largely irrelevant to atmospheric concentration. Their thinking seems to them to be indisputable. i.e. Since we know that atmospheric enhancement is only about ½ our human emission, then removing our human emission would more than account for a reconciliation.
According to some using this thinking, cutting our emission in half might yield a near perfect reconciliation. As if a reconciliation of any sort might produce some meaningful benefit to climate variations (and it would only be, at most, geologically momentary till some natural event changed things again, one way or the other). The cartoon in Figure 4 attempts to illustrate why it is that our contribution is not particularly relevant using some very rough personal yet rational guestimates to make the point.
During the Little Ice Age, natural sinks had overtaken sources so atmospheric CO2 fell (caused by cooling). The warming since then has stimulated natural sources which, in turn, have stimulated natural sinks. And the sources are now out in front, with our modest help to be sure (sinks will always follow sources in both directions). But both sources and sinks have been growing far more rapidly than our anthropogenic contribution in absolute terms. So if our contribution were to be removed in its entirety, there would be little identifiable change. Microbial and insect emissions would more than make up the difference if we let them**. And had we not contributed our 2%, the vegetative sinks would have been most likely under-stimulated by a somewhat similar amount such that there would be little identifiable change. (The water tub analogy where a spigot is filling the CO2 tub, while a drain is draining it, is entirely misleading in the way it is often presented as there is a clearly coupled relationship between changes to the rates of input and output – at least till a saturation event occurs.)
And if the Earth continues to warm, at some point the photosynthetic sequestering sinks will saturate (so that their increasing capacity to sink CO2 will quit increasing). Then very steep atmospheric spiking will ensue just as it so often has in the past. It is very likely that photosynthetic sequestering (biological response) provides an enormous (geologically real-time) negative feedback to additional atmospheric CO2 until such time as it saturates. See Figure 5. This predicted saturation event is not likely very far off into the future if the planet continues to slide sideways on temperature. However, a near-term solar-driven mini ice age may likely interrupt this otherwise predictable event.
**If, for some inexplicable reason, we somehow came to rationally conclude that the Earthly atmospheric CO2 content should rightfully be driven down by our future anthropogenic actions, the most obvious (and simple) actions we could take would involve our further limiting the exponentially growing contribution coming from our competitors in this arena: microbes and insects. A yet further global reduction in their competitive contribution by only ~6% would more than account for the otherwise complete elimination of our anthropogenic CO2 contribution in its entirety. And while this course of action is loaded with potential pitfalls, it is trivially within our anthropogenic means. We have already accumulated a great deal of experience in this regard and already have great insight to its pitfalls (something similar to but possibly much less drastic than what we have done in the lands we use for cultivation and occupation might be performed in certain other lands that we do not currently treat as such). It could likely be done in such a way as to yet further increase crop yields while further minimizing the spread of disease. And it likely is far less subject to unintended consequence than many (all) geo-engineering proposals on the table at this time that I know of – none of which make any sense to me, including this particularly obvious and simple suggested course of action. Why in the world would we choose it inhibit the proliferation of all life on Earth by offsetting our 2% Vitamin C(O2), especially when Nature will continue to wield its 98% in ways totally out of our anthropogenic control.
1. Climate science is very complicated and very far from being settled.
2. Earth’s climate is overwhelmingly dominated by negative-feedbacks that are currently poorly represented in our Modeling efforts and not sufficiently part of ongoing investigations.
3. Climate warming drives atmospheric CO2 upward as it stimulates all natural sources of CO2 emission. Climate cooling drives atmospheric CO2 downward.
4. Massive yet delayed thermal modulations to the dissolved CO2 content of the oceans is what ultimately drives and dominates the modulations to atmospheric CO2.
5. The current spike in atmospheric CO2 is largely natural (~98%). i.e. Of the 100ppm increase we have seen recently (going from 280 to 380ppm), the move from 280 to 378ppm is natural while the last bit from 378 to 380ppm is rightfully anthropogenic.
6. The current spike in atmospheric CO2 would most likely be larger than now observed if human beings had never evolved. The additional CO2 contribution from insects and microbes (and mammalia for that matter) would most likely have produced a greater current spike in atmospheric CO2.
7. Atmospheric CO2 has a tertiary to non-existent impact on the instigation and amplification of climate change. CO2 is not pivotal. Modulations to atmospheric CO2 are the effect of climate change and not the cause.
Ronald D Voisin is a retired engineer. He spent 27 years in the Semiconductor Lithography Equipment industry mostly in California’s Silicon Valley. Since retiring, he has made a hobby of studying climate change for the last 7 years. Ron received a BSEE degree from the Univ. of Michigan – Ann Arbor in 1978 and has held various management positions at both established equipment companies and start-ups he helped initiate. Ron has authored/co-authored 55 patent applications, 24 of which have issued.