Guest essay by Ronald Voisin
(for the near perfect ice-core recordation enthusiasts)
This essay is a promised follow-up to a 1/25/2015 WUWT posting (here).
Some of the WUWT commenters from the initial posting questioned the validity of a 200 yearlong 100% spike in atmospheric CO2. So I’ll begin this follow-up with a defense of that supposition.
It is quite clear that Natural CO2 emission (and atmospheric spiking) is stimulated by any global temperature increase no matter the cause of that increase. The ~1.5oC global temperature rise, since the Little Ice-Age, can reasonably be estimated to stimulate an increase in several of the natural CO2 sources by as much as 2X (in particular the biologic natural sources). See Table 1 below.
Here are 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 argument presented herein the oceans are net emitters as indicated below when warmed by ~0.5oC per century).
Notes: Interglacial estimates come from my notes of IPCC, NASA and NOAA web-sites of 2005 and 2006, when these sites carried detailed analysis of natural CO2 emission sources. Terrestrial estimates of CO2 emission place the anthropogenic contribution at ~3-4%. The annual oceanic release estimate above is modeled (from laboratory experiment by NOAA) and would arise only if and when the oceans begin to follow a 0.5oC per century temperature rise profile (as they most likely have been). Thermal modulations to all non-human emission can be expected to be quite large (up to 2X and more at the extremes of global temp). The only value that can be estimated with high accuracy is the anthropogenic contribution which is far less than both the uncertainty and, most importantly, the variability of many of the natural emission sources.
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.
If one then goes on to recognize that short term (less than a few hundred years) net natural CO2 flux (sourcing and sinking) is dominated by these biological processes. And that natural biologic CO2 sinking is a trailing function of atmospheric CO2.increases (i.e. CO2 sourcing has to go up before CO2 sinking is stimulated to increase). And then assume that Total Earthly Photosynthetic Activity 1850-to-today grows at compounded rate of a mere ~0.35%/year owing to temperature/CO2 stimulation you get a picture that looks like the following.
About the mirrored inflection points graphically shone above:
A) The tiny negative inflection to the larger microbial / insect contribution is far too small to resolve in the immense summation.
B) The large positive inflection to the tiny anthropogenic contribution is also far too small to resolve in the summation at Mauna Loa.
C) Net human activity (apposing at ~2% each) is entirely irrelevant within our limits of current global CO2 detection and evaluation.
D) A geologically instantaneous substitution of approximately equal CO2 emission has taken place between Earth life forms (i.e. anthropogenic agricultural limitation to microbial and insect emission is roughly equal to, but possibly greater than, anthropogenic CO2 emission itself).
We humans have chosen to systematically limit the proliferation of micro-organisms and insects in the lands 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 10’s of large dumpsters per person on Earth).
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 more than our anthropogenic emission from the very land that we systematically exclude them from.
*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” may be a neutral to net negative contribution, and probably is. And the currently observed atmospheric CO2 spiking is essentially all natural.
With the above said, I assert with confidence that atmospheric CO2 spiking results from every global temperature rise. And further that the spiking becomes most acute at or just following the inflection from rising to falling global temperature (with smaller dips associated with the reverse inflection).
Now the question becomes: Why is it that we don’t see these temperature inflection induced spikes in the ice-core record when a myriad of such temperature inflections have occurred throughout the Holocene.
And the answer is: These high-frequency (short duration) spikes are generally not recordable in the ice-cores due to insufficient duration. Why?… Let’s move on to the ice-core recordation process and examine ideal vs. realistic portrayals for an answer.
Let’s assume that the following atmospheric perturbation is to be recorded in the ice (see Figure 1). At some point in time t0, atmospheric CO2 rises from a background concentration of 300ppm, at 3ppm/year, for 100 years. It peaks at 600ppm representing a 100% spike from the original background concentration and then falls in a similar fashion during the ensuing 100 years. The amplitude and duration of the perturbation are arbitrary but, I think, potentially representative of prior real-world events (and possibly we are just now 60 years into recording the beginning of a somewhat similar event at Mauna Loa currently). So how might this atmospheric perturbation be captured (recorded) in Antarctica ice, both ideally and realistically?
First let’s describe the initial conditions for the recording media, at t0 and prior, which might be typically found at a drill site in Antarctica (see Figure 2). On the surface there are a couple meters of loose snow blowing around. Under that there is ~100 meters of firn – partially compacted snow that has been left over nominally in layers from previous seasons of snow. The seasonal age of the bottom of the firn is typically 40 years. Under that there is glacial ice going down to great distance formed from the weight pressure of the firn. This glacial ice represents past seasons, nominally in layers, from 40 years to as many as 800,000 years. Atmospheric CO2 is initially at 300ppm.
In Figure 3 we have a snapshot of the “ideal” atmospheric CO2 recordation at t0 plus 50 years. During these 50 years the atmospheric CO2 concentration has grown from 300ppm to 450ppm at 3ppm/year. The latter 40 years of the 50 are recorded in the firn while the first 10 years have now progressed into the glacial ice.
However, in Figure 3A we see that owing to diffusion a more realistic portrayal has a steeper slope but nominally a similar profile.
In Figure 4 another 50 years of ideal recordation have occurred. At t0 plus 100 years, atmospheric CO2 is now peaked at 600ppm. Again the latter 40 years are recorded in the firn while the initial 60 years have now progressed into the glacial ice.
However, in Figure 4A we see again that owing to diffusion a more realistic portrayal has a steeper slope but nominally a similar profile.
During these initial periods of ever increasing atmospheric CO2 we find that the realistic profile maps quite well on to the ideal profile. But that is about to change.
In “ideal” Figure 5 we are now on the downside of the atmospheric perturbation to be recorded. Atmospheric CO2 has now fallen from a 600ppm peak back down to 450ppm. As before the most recent 40 years are in the firn; and 110 years of recordation have progressed into the glacial ice; including the atmospheric peak at 600ppm.
But now in Figure 5A we see that diffusion back to the atmosphere has produced a very different realistic portrayal of the true recordation process. And this difference will continue to become more pronounced.
In “ideal” Figure 6 at 200 years the atmospheric concentration has dropped back to the initial condition while the firn continues to pass the remainder of the perturbation to the glacial ice.
However, in Figure 6A we see that the realistic recordation bears little resemblance to the ideal. The realistic recordation has retained only ~25% of the ideal amplitude at this point. And it gets worse.
In figure 7 the “ideal” glacial ice recordation is complete. But in Figure 7A only ~7% of the original perturbation is realistically retained.
In Figure 8 we see how this recordation might ideally move another 250 years further into the glacial ice while Figure 8A reveals that only ~5% of the original perturbation has been actually recorded.
And this single source of attenuating distortion is occurring at the initial outset of ice-core recordation process (first few hundred years) notwithstanding an array of big-deal in situ and subsequent recordation distortions – each and every one of which specifically and selectively diminishes “peak CO2” recordation…selectively.
It doesn’t take much mental machination to realize that if the perturbation duration is fixed at 200 years, the results would be similar to what is shown for any amplitude of perturbation – only ~5% would be retained at the initial outset of recordation.
So now it becomes clear why these temperature inflection induced spikes are not revealed in the ice-cores. Many (most) of the Holocene perturbations would involve durations shorter than 200 years such that the ice-core recordation would be basically lost in its entirety regardless of the perturbation amplitude.
It might also be reasonably presumed that temperature/CO2 induced stimulated photosynthetic sinking would generally not allow the spiking amplitude to become greater than 100%; at least not in the absence of a photosynthetic sinking saturation event.
So one good question is: Since the ice-cores do reveal 50%’ish CO2 spikes at the major deglaciations, what minimum perturbation duration would be required such that 50 percentage points of a 100% amplitude perturbation would survive the initial attenuation of recordation? My estimate is something North of 500 years would be required.
One last issue regards the history of thousands of atmospheric CO2 measurements that were carried out by competent metrologists using chemical analysis. These scientists were not dufus. They may not have had accurate techniques but they certainly had precise techniques or they would never have carried their measurements on for years. And it is inconceivable that they all made independent but systematic measurement mistakes (for years), getting erroneously high values, but only during the years following temperature transitions of warming-to-cooling. Chemical analysis clearly reveals atmospheric CO2 spikes, as great or greater than todays, during the 1820’s, mid-1850’s and early 1940’s – in each case following an Earth temperature inflection from rising to falling. And the fact that these same events are absent from the ice-core record is well explained above.
Finally, CAGW isn’t just wrong…it’s entirely and antithetically wrong. Rather than climatic poison, elevated atmospheric CO2 is the elixir of all life on Earth. And misinterpretation/misunderstanding of the ice-cores has contributed greatly to our ongoing confusion. For more info see (here).
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 in 2007, he has made a hobby of studying climate change. Ron received a BSEE degree from the Univ. of Michigan – Ann Arbor in 1978 and has held various management positions at both established semiconductor equipment companies and start-ups he helped initiate. Ron has authored/co-authored 31 patent applications, 27 of which have issued.