Update May 25 below.
We should all know what Alfred E. Neuman knows, namely: Where does all that CO2 come from? Here is the answer from engineer Ronald Voisin.
Excerpts below are from An Engineer’s Take On Major Climate Change
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 (PgC). 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 ~0.5C 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.
Summary
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.
Footnote: Voisin’s article was published in 2013, the facts still overlooked and ignored.
Update May 25
Robert Kernodle provided this chart recently in a separate comment thread.
Those patterns indicate that over millennial time scales, atmospheric CO2 appears as a natural negative feedback to planetary warmer periods. As warming stimulates natural sources, CO2 rises, and after many centuries of delay, temperatures cool down. Ironically, scientists in the 1950s and 60s who raised concerns about a coming ice age maybe had a truer sense of how CO2 is related to climate. Of course, even then they exaggerated the effect of humanity’s 2% contribution, overemphasized decadal fluctuations and mistook CO2 as the cause rather than the effect of warming periods.
Science Matters 
While I agree with these conclusions completely, I have a niggling question I’ve always wondered about.
If atmospheric CO2 increases with an 800 year lag after global temperature increase, does this mean that presently observed atmospheric CO2 increase is a response to a temperature increase ca. 950-1000 AD, aka the Medieval Warming Period?
If so, wouldn’t that schedule us for a major cooling and CO2 reduction sometime between now and 2050!
Hmmmm…
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Thanks Michael. My thoughts go in a similar direction, this Modern Warming Period could be the aftereffect of the Medieval Warming. If so, your speculation is reasonable. Of course, the only future certainty is another ice age, but not soon I hope. Though this is the coolest May in my memory.
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Looks like 1500 years from now, or so for the next glacial advance. Although the geological record is highly variable on that score.
And, of course, the various cosmic cycles are so complex, there’s no predicting it with any level of certainly. It’s likely we’re headed into a century scale cooling, and whether or not that kicks the whole system over into the next advance remains to be seen.
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I am a professor with expertise on element cycles, including carbon. Yes, autotrophs take up CO2 and convert it to sugar and then to other structural materials. The CO2 is released when the plant matter is eaten and respired or when the plant matter is decomposed. These natural cycles are in balance and have no effect on overall CO2. All of the increase in CO2 in the atmosphere is due to burning fossil fuels. CO2 is increasing at about the half the rate that we are burning fossil fuels. The other 50% is taken up by nature, mostly the worlds oceans.
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There is the Garden of Eden belief that nature is in harmony unless or until humans upset the balance. Yet the paleo record shows lots of fluctuations in both temperature and CO2 apart from human activity. Modern observations are showing the seasonal oscillations, as well as uneven CO2 distributions over the planet surface. Nature varies greatly, though within a tight range, indicating negative feedbacks preventing runaway situations. It is true that human participation in CO2 is small and the current rising CO2 trend is also small. That doesn’t prove causation.
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There is no evidence to support the proposition that all of the CO2 increase in the atmosphere is due to burning fossil fuels. If this were so, there would be a discernible pattern in the atmospheric CO2 data that would correspond very closely with fluctuations in human CO2 emissions, which there is not.
The steady rate of atmospheric CO2 increase since 1958 argues for a source in a very large CO2 reservoir, much greater that fluctuating human emissions and even greater than the atmosphere itself. The ocean comes immediately to mind, responding to changes in lower troposphere temperature as a result of natural solar and cosmic cycles.
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Reblogged this on Climate Collections.
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The geological evidence supports the assertion that there is a continuous source of new CH4, which has a low ratio of C13/C12, that is entering the biosphere which is missing from the analysis.
There are two theories to explain how water and hydrocarbons came onto the earth: the late veneer theory and the core extruded CH4 theory.
Roughly 100 million years after the earth was formed a Mars sized object struck the earth. That event formed the moon and stripped the mantel of light elements.
The late veneer theory hypothesizes that comets struck the early earth after the big splat event. The late veneer hypothesis requires that the earth had a Venus like atmosphere (atmospheric pressure of say 60 atmospheres) for the early earth which is not support by analysis of the geological record.
One of the first problems for the late veneer hypothesis is the observation that the percentage of heavy gaseous elements in the earth’s current atmosphere does not match that of comets (Comets are residues of the early solar systems.) which in turn match the element composition of the sun.
The late veneer theory’s explanation for the miss match of isotopes in the earth’s atmosphere to that of comets is that the early solar system had a close encounter with another system which temporary provided a limited source of comets to cover the earth but not significantly change the element composition of the sun.
The second hypothesis is the deep earth hydrocarbon theory. This theory hypothesizes that massive amounts of liquid CH4 (5% of the total core mass) are located in the earth’s core. As the core solidifies the hydrocarbon (CH4) is extruded. At very high pressures the liquid CH4 forms longer chain molecules.
A continual source of CH4 entering the biosphere explains why the solar wind has not stripped off all water from the planet (i.e. CH4 is continually released from planet core which disassociates to form H2O and CO2.
The core extruded CH4 theory also explains why the atmosphere C12/C13 ratio has remained constant with geological time (there is a constant new source of low C13/C12 from the core extruded CH4.) based on analysis of sediments. As plants preferentially use C12 over C13, the ratio C13/C12 ratio would increase if there was not a continual new source of low ratio C13/C12.
The release of CH4 is still occurring as the upper surface of the ocean is saturated with CH4 which indicates that CH4 is being released from some source.
It should be noted that what drives plate tectonics is still an unsolved problem (see below review paper). The hypothesized super high pressure liquid CH4 that is extruded from the core proves the force to drive plate tectonics and explains other geological anomalies such as the Tibetan or Colorado plateaus.
As the liquid core extruded CH4 moves through the earth’s crust it picks ups heavy metals in solution.
At specific pressures the heavy metals are released which explains why there are super concentration of heavy metals (million times concentrated in the crust). Massive concentrations of heavy metals in the crust require a fluid which dissolves the metals, a force that moves that liquid through the earth’s crust, a mechanism for the metals in question to drop out of solution.
The earth’s core started to solidify roughly a 1 billion years ago. At that time, there would be a large increase in CH4 pushed to the surface which explains why there was a dramatic increase in life at that time. The core extruded liquid CH4 raises the continents above the shallow oceans, there is a great deal of CO2 for plants to eat to create the sudden increase in O2 for animal life, and so on.
Click to access Plate%20Tectonics.pdf
The core extruded liquid CH4 explains why tectonic plate movement has doubled in the last 2 billion years.
http://www.sciencedaily.com/releases/2009/09/090910084259.htm
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