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Carbon: Our Life…Our Death?
Mac McQuown, January 10, 2021
All planet-earth’s living organisms derive their life-force from carbon…that includes algae, animals, bacteria, insects, plants, viruses…and indeed humans. Carbon is the centerfold ingredient, the key atom, in all organic material. The earliest forms of carbon-based-life date to shortly after (on the geological time scale) the earth condensed out of the swirl of primordial matter now known by humans as the Solar System. For more than four billion years the sun has been fusing hydrogen into helium and creating the flood of radiated photons that perpetually bombard earth. It is this radiant energy from the sun, “our star” in the Solar System, that is responsible for germinating the earth’s extraordinarily diverse life forms from carbon which was abundant in the earth’s crust, oceans, and atmosphere.
Over the past 10-15 decades, humans have created machines that oxidize carbon in fossil fuels to satisfy their demand for energy…as for example as demanded in communication and transportation. The earth’s crustal carbon was “fused” in a much earlier (than the Solar System) phase of cosmic evolution when an earlier progenitor star-system forged carbon from hydrogen and then went “supernova” blasting that star’s constituent materials into space. Carbon was, that is, a portion of the “raw material” from which earth itself was “made”. Carbon is one of the periodic table’s “118 elements” that were all forged in stars then went supernova. It was then primarily gravitational accretion of these elements floating around in space that formed the next generation of stars, the sun being but a single example of the 100-thousand-million stars that comprise our Milky Way, that is 13.5 billion years old, while the sun itself is only 4.6 billion years old. So, earth’s carbon is older, indeed very much older, than the earth itself. Today on planet earth we can say that…
carbon + energy + time => created an extraordinary variety of life forms
From early human evolution, a few 100 thousand years ago, fire played a pivotal role in keeping wild animals at bay, providing warmth, and cooking plant and animal raw materials into more readily digestible foods. The earth is home to some 10 million species, humans are but one. Protohumans produced fire from the most readily available combustible materials, especially wood. Fire creates more than heat, however. It adds molecules of carbon dioxide, CO2, to the atmosphere. We can label this CO2 as “naturally occurring” if it derived from burning wood, plus that which arises from natural decomposition of organic materials and the out-gassing of volcanos. Therefore, natural specifically excludes the CO2 created by humans burning fossil fuels that has by now accumulated in the atmosphere in prodigious quantity. CO2 from fossil fuels requires an entirely different level of “human creativity and intervention” with their environment. Fossil fuels produce a CO2 molecule that possesses a distinctive carbon-isotopes ratio which distinguishes it from natural CO2. Ice cores extracted from Greenland reveal the atmospheric history of CO2 concentrations back several 100-thousand years: it is all-natural CO2 prior to the late 1800s. From the emergence of human agriculture some 7,000 years ago to near the dawning of the 20th century, the atmospheric natural CO2 concentration hovered in a 100 parts per million range below 300 ppm…that is for at least a half-million years…all from natural sources other than humans burning fossil fuels.
Let me dig a little deeper into this picture…graphically here from Wikipedia:
Since the late 1800s, the natural CO2 that entered the atmosphere was roughly half absorbed by the oceans and continental landmasses, while the other half was retained in the atmosphere. CO2 resides in a three-way equilibrium…atmosphere, landmasses, but the oceans are by far the largest buffer, for it can hold many-times the heat of the land and the atmosphere taken together. It follows that removing massive quantities of CO2 from the atmosphere is going to produce major out-gassing of CO2 from the oceans. When landmasses and oceans reach their absorption limits, the remainder…the 2nd half…simply accumulates in the atmosphere. This “natural balancing act” sustained the atmospheric CO2 concentration under the 300 ppm for hundreds-of-thousands of years as seen in the above graph…before humans disturbed the balance.
Then in the latter fraction of 19th century, humans discovered fossil fuels that rapidly replaced wood as their primary source of energy for cooking, heating, industry, transportation, etc. And most significant, an assortment of technological innovations evolved that have propelled the global economy into an entirely new “technological era” not previously imagined. That is, fossil fuels powered the industrial revolution, the transportation revolution, and today powers the information revolution…and crucially it has provided humans the energy to rapidly expand their numbers and concurrently improve health services to lengthen their life expectancy from under 50 years in 1900 to 80 years today. One consequence of this new “human economic explosion” is the “spike-up” in atmospheric CO2 at the far right in the above graph. This CO2 spike reflects the emergence of new enterprises that have provided the building blocks of today’s “material culture”: aluminum, plastics, stainless steel, synthetic rubber, energy sources, silicon for computer-communication, and in many other products & services previously unimaginable were evolved. That is, fossil fuels provided the energy that has propelled the ever-expanding number of humans, their attendant density in cities with far greater per capita energy demands, their communications and transportation including jet planes, including the very much worse have been the 20th centuries’ wars on a previously unimaginable scale.
We will note that fossil fuels are remnants of ancient mostly former oceanic living matter…vegetative materials and animals…that died and became buried in the earth’s oceanic crust. Buried, this natural organic carbon waste ever so slowly decomposed and became compressed and heated by vast geologic forces into coal, oil, and natural gas that required some 300+ million years to form. Over these millions of years, plate tectonics caused selected sub-geographies of ocean floors to rise including above the ocean’s surface in certain locales, forming continents, as well as deep ocean trenches. So today fossil fuels are widely dispersed below the surface of the planet, on land and in oceans, at various depths that are being extracted to satisfy human demands for ever more energy. In sum, it has been the oxidation of fossil fuels that has powered the present day much admired “standard of living of humans”. And of course, waste from the resultant oxidation has pushed the atmospheric CO2 concentration from under 300 ppm in mid-19th century to today’s 400+ ppm…an increase of 1 trillion tons of CO2, with another trillion tons having been absorbed by the land and oceans. Until recently this atmospheric waste failed to capture sufficient human attention, to which I next turn for more details, including the impending material global warming that is resulting.
The scale of this mass of CO2 now in the atmosphere is not easy to intuitively grasp. In the roughly 150 years since late-19th century, something like two trillion tons… 2,000,000,000… of CO2 have been dumped into the atmosphere by humans burning fossil fuels…beginning with a seemingly harmless trickle to a now gargantuan flood. CO2 was absorbed by the oceans and landmasses…until they could absorb no more, hence the rest remains in the atmosphere. The consequence today is steadily rising ambient atmospheric temperature, for the CO2 blocks the out flow of heat (via infrared re-radiation) from earth that results from the sun’s photon influx. To put this enormous mass in perspective: the trillion tons of residual CO2 resident in the atmosphere is approximately the mass-equivalent of 500 billion automobiles…whereas there are only just over 1 billion automobiles on planet earth today. Moreover as a consequence of ocean and landmass CO2 saturation the atmospheric concentration of CO2 continues to increase. In just the last dozen or so years the atmospheric concentration has risen another 15 ppm to 415 ppm.
More details are instructive… Just consider transportation. Prior to mid-19th century, the primary means of human transportation…besides their own two feet…was the horse that ingested locally grown vegetative materials for its energy and left readily degradable waste, initially smelly but otherwise only providing raw material for fertilization of agriculture. Fossil fuels made possible the first stationary industrial steam engines…1830s…to generate electricity that was soon followed by portable variants to power trains. Then with the refinement of petroleum into progressively higher energy states came gasoline and jet fuel. Now humans can travel distances in a jet plane in an hour that previously required many weeks on horseback. The range of human travel each year continues to increase, mostly owing to jet planes …passenger-miles-flown has more than doubled in the six years to 2020…and with it ever more CO2 being discharged into the atmosphere. It is unambiguous that this energy has propelled economic growth but there is an under-recognized cost: the waste from burning these fuels explains the progressively greater ambient atmospheric CO2 concentration, which in turn is causing the planet to become progressively warmer: about 1 degree centigrade since the late 1800s. It was in 1896 that Swedish scientist Svante Arrhenius quantitively demonstrated that the blocked-radiative effects of CO2 blanketing earth would lead to global warming…but the world at large failed to grasp and act on the dire implications that inevitably followed. And still, too many humans are ignoring that warning.
It was in 1958 that Charles David Keeling, the scientist from the Scripps Institution of Oceanography of La Jolla CA, began measuring the atmospheric concentration of CO2 atop 14-thousand-foot Mt. Mauna Loa in Hawaii. Below is his now famous Keeling Curve that shows the steady climb in atmospheric CO2 concentration from 1958 onward (red is the observed seasonal variation around the blue “fitted” curve):
In 2019, the atmospheric CO2 concentration reached 415 parts per million…an increase of nearly 100 ppm in just over a dozen decades. Moreover, no matter where such atmospheric measurements are taken around earth, the concentration is nearly uniform…meaning that it does not matter where the CO2 was created in the first place, within not many weeks the concentration is nearly uniform everywhere around the planet.
The Keeling curve is of course also a direct consequence of the growth of the human population, as well as energy consumption per capita both of which have been rising steadily. Here are the statistics:
· Human numbers have increased from 1.6 billion in 1900 to 7.3 billion in 2016, a 4-fold increase in just over a century. The population of the US in 1900 was 76 million, today it is 330 million, also a 4-fold increase in the same time interval.
· Even more important, total energy consumption has increased 5-fold since 1950, as the below graph clearly reveals:
· It is especially revealing to convert the above graph into energy consumption per capita, which can be seen below to have doubled just since 1950:
Note: both of the above graphs can be found at:
So, energy consumption per capita has increased some four-fold in two centuries…but per capita consumption has nearly doubled in just the last 50 years. It is this fossil fuels sourced energy consumption that has propelled the standard of living of humans and is now creating global warming from the waste CO2 that was dumped into the atmosphere. Meanwhile, certain segments of humans have failed to get this “picture” straight…notably including many politicians.
Herein resides the telling story of increased energy consumption per capita coupled to ever more people. In just the most recent eight decades the number of cars on the earth grew from about 100 thousand to over 1 billion…a 10,000-fold increase in 80 years. Annual airline passenger-miles-flown has risen from 31 million in 1960 to over 750 million in 2019, 24-fold in forty years. This is the joint consequence of population growth coupled to growth in energy consumption per capita! As already noted, equally unambiguous is the increase in atmospheric CO2 concentration of over 100 ppm since roughly 1900.
Some further perspective can be gained from examining consumption sectors…
· There are five primary energy consuming sectors in the US. Their shares of total primary energy consumption in 2017 are presented below, and all are increasing in total consumption per year over time owing to continued economic growth “powered by” largely fossil fuels:
o Electricity production: 38%
o Transportation: 29%
o Industrial: 22%
o Residential: 6%
o Commercial: 5%
· The sources of the energy consumed by the above five sectors (taken together) in 2017 were:
o Petroleum: 37%
o Natural gas: 29%
o Coal: 14%
o Nuclear: 9%
o Renewables: 11%...mostly hydro and biomass, not yet that much from photovoltaic panels or wind turbines
Fossil fuels are the first three sources, which together explain some 80% of US energy supplied.
Note: the above percentages can be found at different locations on the web, though not all sites present the same breakdowns. Also, from the web I found that the United States is the largest producer of global oil at 18% of the total, with Saudi Arabia and Russia rounding out the top three. After that comes Canada, which produces just under 5%. The total average production in 2018 was about 95 million barrels per day…or 35 billion barrels per year. That amounts to some 4.4 barrels per person on the planet each year.
One important inference can be drawn from these two breakdowns. In the future, each consuming sector will have to devise appropriate new renewable energy technologies to be substituted for today’s technologies that depend mostly on fossil fuels. An example is instructive… LEDs are excellent replacements for incandescent light bulbs because they require far less energy per lumen of light produced; they are longer-lived by well more than a factor of 10; and they have become considerably more production-cost-efficient than the incandescent bulbs they replace. The LED technological substitution is well underway…and myriad other substitutions will necessarily have to dominate every energy consuming sector going forward if disastrous global warming is to be averted. If LED’s economics are indicative of substitutions to come, considerable economic efficiency will also be a very favorable consequence, a crucially important cost benefit additional to the reduction of waste CO2.
Only recently has it come to be understood that fossil fuels produced CO2 waste dumped into the atmosphere has a lifespan there of several centuries…in part a consequence of natural CO2 saturation of landmasses and especially the oceans, which have vastly greater absorption capacity. Scientists today find global warming is the direct consequence of the 100+ ppm increase in CO2 in the atmosphere over the recent fifteen, or so, decades. The current “best estimate” (from a renowned Professor colleague at Scripps Institution of Oceanography) is that the average global temperature is already about 1-degree-C higher than circa 1900. CO2 blocks the natural infra-red radiant heat outflow from the planet, a consequence of the energy that originally enters the earth’s atmosphere as ultraviolet solar radiation. That is, a major fraction of the ultraviolet solar energy influx hitting earth would be radiated outward into space at infrared frequencies…if it were not for the CO2 “blanket” surrounding earth that prevents it. Hence the planet’s average ambient temperature is trending upward, to wit “global warming”. As previously noted, about half of the unnatural CO2 dumped into the atmosphere by humans has been sequestered by the oceans and the landmasses, while the other half remains in the atmosphere…which explains the origin of the 100+ ppm atmospheric increase in the last fifteen decades.
Given CO2’s life expectancy in the atmosphere, global warming will continue for centuries after the total secession of burning of fossil fuels.
· It unambiguously follows that we humans need to remove a substantial amount of currently estranged atmospheric CO2…and ASAP.
· If we fail to remove a substantial quantity of CO2 currently in the atmosphere within a few decades, earth will simply continue to get warmer.
The cost of global warming impact must be taken very seriously. With just above 1+ degree C warming so far, we have melting glaciers at both the north and south poles, and the permafrost in the artic is thawing releasing prodigious quantities of methane. Looking three decades ahead, methane is 30 times more potent than the warming influence of CO2. Thus in effect, there is an accelerating effect produced by CO2 as it also causes methane to be outgassed owing to its warming. One readable paper of note on this topic is “Experimenting with Earth” by Ramanathan and Barnett- 2003 (003) from the “Wilson Quarterly”.
Consequently, the technical and economic challenge is how are we going to capture and dispose of this unnatural ambient atmospheric CO2 concentration, and at what cost…and paid for by whom. These are the crucial questions that humans must solve, and implement in no more than three decades.
There is an already noted non-negligible challenge to removing ambient CO2 from the atmosphere. For every, say, 10 ppm of CO2 that is removed from the atmosphere, the atmospheric concentration will not drop by 10 ppm. The reason is that “disturbing the existing equilibrium” between CO2 in the atmosphere, oceans, and landmasses will cause especially the oceans to outgas some of their estranged gaseous CO2. Just how much CO2 will return to the atmosphere is a topic of much discussion and concern among the foremost atmospheric scientists.
What also remains significantly unclear is just how much damage will be caused over the decades from today before burning fossil fuels comes to an end. In any event, this social-cost-of-carbon is not being born by those who are benefiting from the current energy consumption. That is those who are polluting today are not paying for the waste they are creating; future generations will pay for the consequences of the CO2 waste produced today. The crude assumption-driven (as opposed to data-driven) estimate puts the present-day US government’s “model” of the social-cost-of-carbon below $50 per ton of CO2. Current research at the University of Chicago, under the direction of Professor Michael Greenstone, executive director of the Becker-Friedman Institute, will have a data-driven estimate of the social-cost-of-carbon in 2021. My personal guess from what I have learned so far is that it will at least double the current social-cost-of-carbon “assumption” putting it “north of” $100 per ton, and it even could be significantly higher. Stanford scientists, case in point, currently conclude that the social-cost-of-carbon exceeds $200 per ton: (https://news.stanford.edu/2015/01/12/emissions-social-costs-011215/).
Some additional numbers add perspective. One ton of coal produces approximately 2000 kwh of electricity, depending primarily on the extent of impurities in the coal and the efficiency of the coal-burning plant’s technology. The total annual production of electricity in the US alone is some 3.8 trillion kwh, 14% of which is from coal…so about 0.5 trillion kwh are produced annually just from coal. Thus, 0.5 trillion kwh divided by 2000 kwh/ton implies that 250 million tons of coal are currently being burned annually to produce electricity in just the US. Since burning 1 ton of coal produces 2.8 tons of CO2…then approximately 250 million tons times 2.8 produces some 700 million tons of CO2 annually that is dumped into the atmosphere from the energy sourcing just from coal, and just in the US. That is just the CO2 produced from coal…next we examine the direct financial economics of coal.
The average price paid by the US consumer for a kilowatt-hour of electricity averages some $0.12. Hence consumers currently pay about $240 for the electricity that a ton of coal produces. However, consumers do not pay for the CO2 waste consequences that result from the burning of that ton of coal. To repeat: each ton of coal when burned produces 2.8 tons of CO2. If the refined estimate of the social-cost-of-carbon turns out to be $100 per ton, then the waste produced has a future cost to society of something like $280 per ton. Meanwhile, Stanford’s scientists have put the social-cost-of-carbon at $220 per ton of waste CO2, so the CO2 waste would have a cost of more than double, so nearly $500 per ton . Therefore, in round numbers the consumers of this energy sourced from coal are only paying somewhere between one-quarter and one-half of the actual relevant total cost of burning coal for their electricity demand. If this ratio also applied to gasoline refined from petroleum…which fortunately it does not so bad…then the current price of around $3 a gallon at the filling station when “fully costed” would put the price between $6 and $12 per gallon. What does this suggest about the level of demand for fully costed gasoline?
Note: the numbers in the prior two paragraphs came from several sites on the web that the author deems reliable, and there are many sites that present numbers that vary somewhat from site to site…but again these numbers suffice for purposes of this discussion.
While I have recently read that there is growing agreement among leading economists that there should be a tax imposed on CO2 waste, two important questions get thereby raised. Should the tax cover (my crudely estimated) full $280 waste cost of burning coal? And second, what should the government do with the collected proceeds? The only reasonable use of said tax proceeds would be to sequester the existing atmospheric CO2 concentration. That is the tax should be used to remove some fraction of the 100 ppm that has been dumped into the atmosphere in the past fifteen decades. Therefore, if this CO2 waste cost was taxed at 100%, then 700 million tons of CO2 per ton of coal times even at $50 per ton (the present widely assumed social-cost-of-carbon) equals nearly $35 billion in collected taxes. And then just suppose that the other fossil fuels… petroleum and natural gas…dumped into the atmosphere produce about the same amount of CO2 per ton (which fortunately they do not). Then the total unnatural CO2 dumped into the atmosphere by humans would be 7-times more than from just coal, or some $250 billion. Let me put that amount in perspective: the cost of the entire US public school system is about $600 billion annually. And if the social-cost-of-carbon turns out to be $200 per ton of CO2, then this unnatural CO2 waste dumped into the atmosphere is approaching the annual cost of the entire public-school system.
It is even more revealing, and far more disheartening, to discover the size of the US federal government subsidy of the fossil fuels industry. These subsidizes are ten times the amount paid by the government on public education! See the following article on the web:
If this ten-times subsidy is correct, then the financial economic impact inferred above is substantially greater than the cost of the entire public-school system. Considering the damage that burning fossil fuels is already having and will continue to impose on the bio-culture of the planet, how can any subsidy of the fossil fuel industry be tolerated? The government’s policies are taking already very bad “underlying” financial economics and this says matters are actually 10-times worse. Here is an egregious failure in US government accountability and responsibility.
We have far poorer estimates, for example, of when the resultant global warming will cause the ocean to expand and rise to a given elevation because we are more dependent on modeling assumptions than on measurements. Of course, the social-cost-of-carbon estimate emerging from Prof. Greenstone’s research at U of Chicago will include an estimate of how much damage the ocean level rise would induce. However, there is one crucial implication worth reiterating: even if all fossil fuel burning stopped immediately, all the planet’s living systems will continue to encounter a progressively warmer environment and a variety of undesirable implications that follow from the extent of CO2 already in the atmosphere. Today’s 400+ ppm CO2 concentration and centuries-long lifetimes assures that consequence…the only ambiguity revolves around how much damage will result and when. Clearly if global warming is to be avoided, a large fraction of what humans have already dumped into the atmosphere must be removed. This removal will have to deploy an assortment of “artificial” means…that is human created technologies together with the required energy…because the oceans/landmasses natural sequestration have already proven insufficient: they are already saturated. That is, the natural environment cannot handle the unnatural CO2 in the atmosphere for otherwise we would not find the 100 ppm increase that we do find.
Be reminded: the natural environment (oceans, landmasses) already has taken up the equivalent of another 100 ppm from human burned fossil fuels, for otherwise we would be finding 200 ppm increase in the CO2 atmospheric concentration…the total quantity humans have dumped there. Restated for emphasis: there has been some 2 trillion tons of CO2 dumped into the atmosphere in the last 10-15 decades. Today, only 1 trillion tons remains in the atmosphere…which is the incremental 100 ppm increase…at least half of which must be artificially removed by humans to avoid tragic warming.
Of course, humans have enjoyed enormous benefits from the energy that burning fossil fuels has provided…apart from the serious consequence of supporting billions more people. This conclusion may attain no matter how human energy demands are met. Getting rid of fossil fuels does not say that the benefits it created over the last fifteen decades from the emergent advanced industrial/transportation/information society cannot continue. The irony is that the emerging renewables energy sourcing is more than able to meet our future energy demands both without any CO2 waste and at appreciably lower cost per kwh. That transition is now underway in earnest, independent of the government’s subsidizing the fossil fuels industry.
An aside without delving into the myriad facts and attendant reasoning, this author concludes that hydrogen derived from clean…or “green”…sources via various technologies will play a crucial role in meeting human energy demands going forward. Hydrogen is super-abundant, has more “energy density” than gasoline with far fewer limitations, will be more economic than fossil fuels, and is 100% safe with no harmful waste. This topic is, however, distant from these comments on carbon and life on earth, and it would require another paper of similar length.
Then to summarize and conclude…the only remedy for global warming, in addition to total suspension of burning fossil fuels ASAP, is to remove and dispose of a substantial quantity of today’s atmospherically estranged CO2 in the next few decades. This author believes that entirely reasonable conjectures have it that we need to return the atmospheric CO2 concentration to something like 350 ppm in 3-4 decades to avoid substantial warming. So, that probably means removing at least half-a-trillion tons of CO2…that is 500,000,000 tons. Human-devised removal technologies, and their massive energy requirements, are needed to remove the CO2, and indeed to safely dispose of it. We humans have no alternative if severe global warming is to be avoided. The political rhetoric that a carbon tax needs to be “revenue neutral” is nonsense. If we fail to remove the needed quantity of CO2 already estranged atmosphere the consequent global warming will threaten all life on earth.
Indeed, it is abundantly clear that the continued burning fossil fuels and the failure to sequester the prior decades atmospheric accumulation of CO2 spells extinction for many of earth’s living systems. Might this include humans too? Only time will tell...
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