ClimateSIM Junior, Simplified Prognostication from Unrealistic Hypothesis

Painting of the Roiling Ocean, by Ivan Konstantinovich Aivazovsky

<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>

ClimateSIM Junior, Simplified Prognostication from Unrealistic Hypothesis

Let me call the complicated work of supercomputer climatologists “ClimateSIM Senior.” Their efforts result in very complex “computer games” that simulate, up to a point, the Earth’s climate history, past and future.

What follows is a description of “ClimateSIM Junior,” my “speculative science” effort to model Earth’s climate, using formulas devised on pads of paper and numbers arrived at with a hand-held calculator (HP45). My purpose here is to present a simplified and only mildly inaccurate picture of “what is,” and to project from that with complete positive thinking, to ‘guesstimate’ “what could be.”

For data, I used the summary of the Carbon Cycle as published by the IPCC in 2007 (reporting on 2004 data), and a variety of estimates I have made and reported on over the course of the last year. The numbers to be presented are all internally consistent for the ease of storytelling, but the realities they represent are not actually known to the exactitude implied by the numbers shown.

Finally, I am not competing with nor contradicting ClimateSIM Senior, just trying to understand it better.

In 2020, the anthropogenic emissions of carbon dioxide gas (CO2) from Earth’s land surfaces is 36.3Gt/y (Gt/y = giga metric tons per year, or units of 10^12kg/year). This composite plume is split between industrial CO2 pollution, at 29.3Gt/y, and land use (or misuse) CO2 pollution at 7Gt/y.

Natural emissions of CO2 from land surfaces are: 0.3Gt/y from volcanoes, and 440Gt/y from respiration. The total of CO2 emissions from land surfaces is 476.6Gt/y.

The yearly absorption (or fixing) of CO2 from the atmosphere by land surfaces has three components: 0.7Gt/y by weathering reactions on soils and rocks; 440Gt/y by photosynthesis as in the pre-industrial past; and an additional 0.4Gt/y by photosynthesis in recent years. The total absorption of CO2 by land surfaces is 441.1Gt/y.

At present, land is a net emitter of CO2, at the rate of 35.5Gt/y, all anthropogenic.

The natural emissions of CO2 by the oceans, at present, are: 260Gt/y of CO2 released as in the pre-industrial past; and an additional 70Gt/y released in recent decades. The net emission from the oceans is 330Gt/y.

The uptake or absorption of CO2 by the oceans is: 260Gt/y as in the pre-industrial past; with an additional absorption of 80.4Gt/y in recent decades. The net absorption by the oceans is 340.4Gt/y.

At present, the oceans are net absorbers of CO2, at the rate of 10.4Gt/y, all anthropogenic.

With lands emitting 35.5Gt/y, and oceans absorbing 10.4Gt/y of it, CO2 is accumulating in the atmosphere at the rate of 25.1Gt/y, which is equivalent to a rise in the partial pressure of atmospheric CO2 of +3.2ppm/y (ppm = parts per million). We are at 417ppm now; if nothing changes then in one year atmospheric CO2 should be at 420.2ppm.

The anthropogenic accumulation of CO2 in the oceans is 481.2Gt (my estimate; “500Gt” or “about 500Gt” are casually stated elsewhere), and the average acidity level of the oceans is at a pH of 8.1. Today’s oceans are 26% more acidic than they were in pre-industrial times, when their pH was 8.2.

Now let’s dream. Imagine that all anthropogenic CO2 emissions cease immediately and permanently. The lands would become net absorbers of CO2, at the rate of 0.8Gt/y (by weathering reactions despite volcanic outbursts, plus lingering added photosynthesis). This clearing rate is equivalent to -0.10ppm/y. The 137ppm of excess CO2 above the pre-industrial level of 280ppm would be cleared away in 1,359 years. Further accumulation of CO2 in the oceans will have ended with the cessation of anthropogenic emissions.

The global temperature would continue to rise (because of atmospheric and oceanic heat-retention effects at a higher temperature than in pre-industrial times), but at a slower and slower rate, peaking at +3.8°C of average global warming above the temperature of 1910 (and +2.8°C above today’s global average temperature), for the century 300 to 400 years from now. Cooling would ensue thereafter, with a return to pre-industrial (1910) conditions in about 1,350 years from today.

By that time the terrestrial part of the Carbon Cycle would have returned to its pre-industrial level of performance, with the land surfaces acting as net absorbers of atmospheric CO2 at the rate of 0.4Gt/y, equivalently -0.0504ppm/y of atmospheric CO2 reduction.

With the atmosphere cleared of anthropogenic CO2, and its partial pressure reduced to its pre-industrial level, the oceans could begin an extra release plume of CO2 gas at a rate of 0.4Gt/y, to be fixed by weathering reactions on land. The atmospheric concentration of CO2 would remain stable at 280ppm (with minor natural fluctuations). The anthropogenic load of CO2 in the oceans would be cleared in 1,203 years, and their acidity would return to their pre-industrial level of 8.2pH.

Nearly all of the anthropogenic caloric load accumulated by the biosphere is stored in the upper 500 to 1,000 meters of the oceans, and is concentrated at the top. With the onset of atmospheric CO2 reduction and overall biosphere cooling (more heat, as infrared radiation, being radiated into space without being blocked by an excessive CO2 “thermal blanket”), oceanic anthropogenic heat would be able to diffuse out of the waters and radiate away. Over the 1,203 year time span of oceanic de-acidification, the excess heat stored in the upper 73 meters of the oceans would be radiated away (and excess heat from the cooler depths will have diffused closer to the surface).

Logically, there would be an overlap in the time spans over which the air and oceans, respectively, are cleared of their anthropogenic loads of CO2 and excess heat, but to calculate that with any degree of believability is a job for ClimateSIM Senior.

Today, this is the best unified story I can tell about the most optimistic hypothetical case for Earth’s recovery from global warming. It lies somewhere between a quantitative engineering estimate, and a dream.

Now for some policy recommendations. My suggestions to the Economic Mandarins of the United States are as follows:

If those Mandarins are Neoliberals:

1. Use that bloated, over-equipped U.S. military colossus to invade Brazil and gain control of the Amazon Basin. Then, stop the fires, kick out the ranchers and miners, and rehabilitate the rainforest “lungs of the Earth” to tamp down the onslaught of global warming. Also, help out the Brazilian people while you are at it.

2. A second target for the same type of action as in the above, is Siberia. But be sure not to spark a nuclear war in trying to gain control of it (so, don’t be too hasty, and also use diplomacy). Remember, stabilizing the geophysical climate aids in stabilizing a reliable business climate.

If those Mandarins happen to become Socialists:

1. Use that bloated, over-equipped U.S. military colossus — if you are unwilling to dismantle it because it is a “public works” program — to implement the 2 recommendations given to the Neoliberal Mandarins.

2. Also, immediately invade all offshore tax havens (many concentrated in the Caribbean) to repatriate tax-avoiding hoards hidden there. Use those stolen-from-the-public funds to underwrite the costs of maintaining the lives, for life, of all the nation’s people.

3. A good portion of the funds liberated from militarized and pirated-private sequestration will necessarily go to mitigating the impacts of global warming, in a variety of ways applied regionally.

4. It will also be necessary to contribute to international efforts at global warming mitigation and standard-of-living equalization, to simultaneously help meet national goals in those regards.

Being realistic, nobody really wants to hear about global warming, whether they are in government, business, or an “ordinary” member of the pubic. Government people don’t want any interruptions to their careers being in positions of power (and making money); business people don’t want any interruptions to their careers making money (and being in positions of power); and most members of the public just want an uninterrupted continuation of their comforts and entertainments — if they are not in absolute terrified panics over threats to their physical and economic survival, and don’t have the luxury of worrying about global warming.

As a result, there is no limit to how bad we can make global warning; which the Trump Administration (in the U.S.) and the Bolsonaro Administration (in Brazil) seem to be taking as a challenge.

In terms of dreams of utopia versus fears of doom and perdition, realize that the best utopia we could achieve would pale in comparison to our dreams about it, but be far superior to the conditions we live under today. If we are doomed by fate regardless of what good efforts we can make at improvement, then we will all drown together in that doom, whether we do so while exploiting each other mercilessly and quarreling bitterly, or whether we do so supporting each other in admirable solidarity. It is our epitaph to choose: nobility or ignominy. And, if we choose the former, an epitaph won’t be necessary.

<><><><><><><>

The Improbability of CO2 Removal from the Atmosphere

<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>

The Improbability of CO2 Removal from the Atmosphere

The concentration of carbon dioxide gas in today’s atmosphere is 417ppm (parts per million). There are 10^44 gas molecules in the entire atmosphere (78% diatomic nitrogen, 21% diatomic oxygen, 1% everything else), so 1ppm is equivalent to 10^38 gas particles. The 417ppm of CO2 represents a total of 4.17×10^40 molecules.

Some people hope for new technology to remove carbon dioxide gas from Earth’s atmosphere, and then forestall the advance of global warming, or even completely eliminate it. I see this as improbable because I think any such technology would be extremely inefficient at CO2 removal, and be energy intensive as well. The process of gaseous diffusion, as with the release of CO2 into the atmosphere, requires no energy; the gases just mix, spread and dilute, and the entropy of the atmosphere increases. It is an “irreversible process” in the parlance of chemical thermodynamics. This means that the spontaneous un-mixing of gases and their re-concentration into separate volumes has never been observed. Energy must be invested to effect any such desired separation of component gases in a mixture. To explore the possibility of CO2 removal, I have quantified my sense of improbability about it, and describe that here.

Consider a hypothetical CO2 removal machine that is a tube with a filter box in the middle. Air is fanned into the tube, flows into the filter box where some of its CO2 is removed, and then flows out of the tube to rejoin the atmosphere and to slightly reduce the global average concentration of CO2. Energy is supplied to entrain air into the device, and energy is supplied to power the unspecified process that effects the CO2 removal within the filter box. The machine would operate continuously so that over time all the atmosphere would be filtered and de-carbonized.

This would be a very large machine, and most likely be a large array of identical or similar units all over the world that would comprise a composite machine. I will describe this composite as if it were a single tube. [1]

Machine #1

This machine has a filter cross-sectional area of 10,000 km^2 (10^10 m^2) into which air is fanned through at 1meter/second (2.24mph). Producing that continuous mass flow from still air requires 16GW of power, assuming an efficiency of 40% (from raw power into moving air). The filtration process is assumed to consume 40GW (1% of the power used by the United States) and be 1% effective at CO2 removal. The anthropogenic emission of CO2, at its current rate of 35.5GT/year (giga metric tons per year), is assumed to continue indefinitely (the economy!), with the oceans absorbing 29% of those emissions (10.4GT/y).

At the end of 10 years of continuous operation Machine #1 would have cleared 3.26ppm of CO2 from Earth’s atmosphere, at a cost of 1.77×10^19 Joules of energy (4.92×10^12 kilowatt-hours). Reducing the CO2 concentration to the pre-industrial level of 280ppm would require 507.6 years.

Machine #2

Clearly, improvements are required for Machine #1. So, we assume that 10% efficiency of CO2 removal can be effected by investing 400GW (10% of the power used by the United States) into the filter box. Now, the power consumption is 416GW for Machine #2. After 10 years of continuous operation 31.5ppm of CO2 would be removed from the atmosphere (bringing the concentration down to 386ppm), at an energy cost of 1.31×10^20 Joules (3.64×10^13kWh). Reducing the atmospheric concentration of CO2 back to 280ppm would require 51 years. This might seem promising except for the fact that the assumed 10% efficiency is pure fantasy.

Machine #3, All Earth’s Lands

To regain a sense of reality, consider the actual performance of the entire land surface of the Earth (1.489×10^14 m^2) acting as a CO2 removal filter. This was the case in the clearing of 2500ppm of CO2 from the atmosphere over the course of 200,000 years during the geologically brief episode of explosive global warming 55.5 million years ago, known as the Paleocene-Eocene Thermal Maximum (PETM). I described the PETM and cited numerous public-access scientific references to it in [2].

Using the same rate of CO2 removal (the e-folding time) as occurred during the PETM, in my formulation of CO2 removal machines, it transpires that the efficiency of removal by the Earth-filter (rock weathering reactions in the long term) is 8.6×10^-8 (0.0000086%). After 10 years, this Earth-machine would clear 0.42ppm of the atmospheric CO2 (bringing the level down from 417ppm to 416.6ppm). That level would be reduced to 280ppm in 3,984 years.

Machine #4

Hope in technology springs eternal for some, so maybe our Machine #2 even with a realistic efficiency can better the clearing-time set by the Earth, natural Machine #3. We accept an efficiency of 1.474×10^-7 (0.00001474%), invest 1.31×10^19 Joules of energy every year at a rate of 416GW of continuous power, and after 10 years find 0ppm of CO2 removal! In fact however long we run this machine there will always be 0ppm of CO2 removal, because the rate of technological removal is equalled by the rate of anthropogenic emissions. Reaching 280ppm is literally infinitely far away.

Machine #5

Maybe by some technological breakthrough the efficiency can be raised by a factor of 100, to 1.474×10^-5 (0.001474%). Then in 100 years Machine #5 would have cleared 0.0478ppm of atmospheric CO2 (reducing the level from 417ppm to 416.95ppm) for an investment of 1.31×10^21 Joules (3.64×10^14kWh). Achieving 280ppm would require 348,577 years. It’s hard to beat the Earth at its own game.

Best Course of Action

It should be obvious by now that our best course of action is to apply our energy resources to the betterment of our many societies and the equalization of living standards worldwide, and to the transformation of our economic activities for minimal CO2 emissions. The current catch-phrase for this transformation is “degrowth.”

During this pandemic year of 2020, the U.S. GDP shrank by 33%, and the CO2 emissions by the United States also shrank by the same proportion. Worldwide CO2 emissions shrank by 17%. Zero emissions require zero GPD, as we now know it.

Global warming will advance and its consequences will add great stresses to many human, animal and plant populations. This geophysical process could be experienced as “the collapse of civilization,” or it could be taken as a collective challenge to advance human civilization by bonds of solidarity, and the restoration of its reverence for the natural world. If we put our energy into fashioning that imperfect utopia, we would live through global warming with a justifiable sense of pride, and even have fun.

Notes

[1] Stream Tube CO2 Removal Machine
8 August 2020
Stream Tube CO2 Removal Machine
or
https://manuelgarciajr.files.wordpress.com/2020/08/stream-tube-co2-removal-machine.pdf

[2] Ye Cannot Swerve Me: Moby-Dick and Climate Change
15 July 2019
https://manuelgarciajr.com/2019/07/15/ye-cannot-swerve-me-moby-dick-and-climate-change/

<><><><><><><>