revious 7 years). From 1960 to the present day, the trend of cumulative production of petroleum, Q, has been proportional to the rising trend of human population, in the ratio of 272 barrels of oil per person (272 b/p).
Specifically, my approximating formula for Q, the accumulated production of oil in giga-barrels (Q, in Gb), given as a function of the population in billions (P, in B) for a given year within the interval 1960 to 2025 is:
Q(year) = [P(year) – 2.7B] x (272 b/p).
This approximation gives an accumulated production up to 2015 (with population 7.35B) of
Q(2015) = 1265Gb, (approximation).
By integrating the actual production rate-per-year curve (the “Hubbard curve” for world production, in GB/yr) given by Laherrere (2), I find the actual accumulated production up to 2015 to be:
Q(2015) = 1258Gb, (actual).
The rate of oil production is now likely at its peak of between 25 Gb/yr to 35 Gb/yr during this 20 year interval between 2005 and 2025, (2),(4). Thereafter, it should drop rapidly since current oil fields have diminishing production, there have been no major oil field discoveries since the 1970s and the frequency of discovery has steadily diminished since then. That means that over half of Earth’s original total reserves, estimated at 2,200Gb (2), have already been extracted. The “end-of-oil” seems destined for the last two decades of the 21st century.
Assuming all that oil was burned, up to the year 2015 (115 years since 1900), civilization would have used 7,674GGJ, (7,674 x 10^18 Joules), equivalent to 2,139GMWh, (2,139 x 10^15 Watt-hours) of energy, derived from that 1258Gb of petroleum, to power itself.
That burning would have released 398,786Gkg (~4 x 10^14 kg = ~400 giga tonnes) of CO2, (5). At present (May 2019) there are about 3,250 giga tonnes of CO2 in the atmosphere, with an average concentration of 415 parts per million by volume (415ppmv), (6). 1228 G tonnes of that CO2 is excess above the pre-industrial amount in the atmosphere. The ~400 G tonnes estimated here as the accumulated emissions from the prior burning of petroleum (up to about 2015) is only about one-third of the excess atmospheric CO2.
There are numerous other processes in our civilization, as well as in the natural world, that cause the emission of carbon-dioxide and its atmospheric retention in excess amounts. The main sources of CO2 emissions are the exhalations from aerobic respiration by all of Earth’s living heterotrophs, decaying plants, and volcanic eruptions. Other sources include: the burning of coal and natural gas, forest and vegetation fires caused naturally and by slash-and-burn agriculture, the bubbling out of CO2 from warming oceans no longer able to dissolve as much of that gas as before, and the massive amount of past and continuing forest clearing that has reduced Earth’s natural system of CO2 uptake — photosynthesis. The cement industry is one of the two largest producers of anthropogenic carbon dioxide, creating up to 5% of worldwide man-made emissions of this gas, of which 50% is from the chemical process and 40% from burning fuel, (7).
Methane (CH4) is a very potent greenhouse gas, being 30 times more effective than CO2 at trapping heat. “For each degree that Earth’s temperature rises, the amount of methane entering the atmosphere from microorganisms dwelling in lake sediment and freshwater wetlands — the primary sources of the gas — will increase several times. As temperatures rise, the relative increase of methane emissions will outpace that of carbon dioxide from these sources.” (8) Other sources of methane emissions are: rotting organic wastes, termite colonies, and bovine flatulence from industrialized agricultural sites. The globally warmed thawing Arctic tundra is now a region of major methane eruptions.
Up until 1974, when the human population had reached 4B, Earth’s climate system had yet to become feverish over the previous 200,000 years of collective human activity. However, at about that time the average global temperature began increasing at a historically unprecedented rate because of civilization’s heated and organic outgassing, a process which continues today as anthropogenic global warming, (9).
In fact, the date at which collective human activity began to affect and alter Earth’s climate system has now been pinpointed to somewhere between October to December 1965. That date marks the end of the Holocene Epoch of geologic history (which began 11,700 years previously, after the last Ice Age), and the beginning of the Anthropocene Epoch — the epoch of human-affected climate, globally. The physical phenomenon marking this transition is that Carbon-14, a radioactive isotope released during open-air atomic and nuclear bomb explosions between 1945 and 1963, had finally dispersed uniformly around the globe, and become absorbed into tree tissues even in the remotest parts of the world, thus recording that uniformity (10).
Between 1960 and 2025, the three rising trends of: population (P), cumulative oil production (Q), and increase of average global temperature above baseline (T – 14.7C = delta-T), are all uniformly proportional to one another.
Specifically (for years between 1960 and 2025) T, P and Q are related to each other as follows:
[T(year) – 14.7C] = [P(year) – 2.7B]/3.3B = [Q(year)/(900 Gb)],
where the forms above are each equivalent to a temperature difference relative to the baseline of 14.7C (delta-T, in degrees C).
Notice that if T = 15.7C, and P = 6B, and Q = 900 Gb, then the equality above holds, with: 1 = 1 = 1. This particular condition actually occurred during 1999.
During this 65 year interval, a 1 degree C rise in temperature (above 14.7C) is coincident with a 3.3B increase in population (above its 1953 level of 2.7B), which in turn is coincident with a production (and use) of 900Gb of petroleum.
The population is growing from 3B in 1960 to an expected 8B in 2028 during this 68 year interval, with an average population increase of +73.5M/yr. Within these 68 years, and especially during the 55 years from 1970 to 2025, the rising trends of (T – 14.7C), (P – 2.7B)/3.3B, and Q/(900Gb) are in lockstep. This period — with explosive population growth, depletion of over half of the Earth’s petroleum endowment, and with an unprecedented rate of global warming — began in the last year of the Eisenhower Administration, 1960, when John Kennedy was elected US President, and extends right up to the present (and beyond it).
The average global temperature will have climbed up from ~15C to ~16.2C during this interval, a relative rise of 1.4C, and a rise of ~1.5C (delta-T = ~1.5C) above the pre-industrial temperature, defined here as 14.7C (58.46 degrees Fahrenheit). That 1.5C (2.7F) warming above the pre-industrial temperature represents a tremendous amount of heat energy diffused throughout the biosphere, and the deleterious effects of that excess heat are self-evident to all: the altering of climate; the powering of violent weather; the heating and acidifying (with absorbed CO2) of the oceans, sterilizing them of marine life; the melting of glaciers and thawing of tundras; the causing of carbon dioxide and methane to bubble out of solution and frozen capture in the natural world (in a vicious feedback loop); the expansion of disease pathogens and tropical parasites; and the added stresses to both wild and farmed vegetation, and increased desertification, which result in human hunger and desperate migrations of impoverished refugees.
Now, our civilization is starting to suffocate in the lingering heat of its previous exhalations. The singular challenge to our species and to our political economies is what to do, collectively, about global warming. That challenge remains largely unanswered, and tragically denied by too many people .
Notes
1. World population is estimated to have reached one billion for the first time in 1804. It was another 123 years before it reached two billion in 1927, but it took only 33 years to reach three billion in 1960. The global population reached four billion in 1974 (14 years later), five billion in 1987 (13 years later), six billion in 1999 (12 years later), and seven billion in October 2011 (12 years later), according to the United Nations, or in March 2012 (13 years later), according to the United States Census Bureau.
https://en.wikipedia.org/wiki/World_population
World population by year
https://www.worldometers.info/world-population/world-population-by-year/
2. Jean Laherrere, World Crude Oil Production, (brown line), April 2015
3. The energy released from combusting 1 barrel of oil is 6.1 giga-joules (6.1 GJ), which equals 1.7 MWh (1 mega-watt-hour).
https://en.wikipedia.org/wiki/Barrel_of_oil_equivalent
4. Worldwide, around 92.6 million barrels of oil were produced daily in 2017.
https://www.statista.com/statistics/265203/global-oil-production-since-in-barrels-per-day/
~73 million barrels/day in 1998, rising since.
73 Mb/day = 26.7 Gb/yr (1998)
93 Mb/day = 34.0 Gb/yr (2017)
During 20 years of production (1998-2017) the rate rose 20 Mb/day = +1 MB/day/year
5. Burning one barrel of petroleum can produce between 317kg (realistically) to 433kg (theoretically) of CO2:
Realistic
http://numero57.net/2008/03/20/carbon-dioxide-emissions-per-barrel-of-crude/
Theoretical
https://www.answers.com/Q/How_much_CO2_produced_by_burning_one_barrel_of_oil
Therefore, the CO2 emitted by combusting 1b = 317kg CO2.
6. As of January 2007, the earth’s atmospheric CO2 concentration is about 0.0383% by volume (383 ppmv) or 0.0582% by weight. This represents about 2.996×10^12 tonnes (1 tonne = 1000kg), and is estimated to be 105 ppm (37.77%) above the pre-industrial average (~278 ppmv).
https://micpohling.wordpress.com/2007/03/30/math-how-much-co2-by-weight-in-the-atmosphere/
415 ppmv of atmospheric CO2, as of May 2019
https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmosphere
Therefore:
(415/383) x 3000 G tonnes = 3,250 G tonnes, (May 2019).
7. Environmental impact of concrete
https://en.wikipedia.org/wiki/Environmental_impact_of_concrete
8. Methane is roughly 30 times more potent than CO2 as a heat-trapping gas
https://www.sciencedaily.com/releases/2014/03/140327111724.htm
9. I first constructed the simplified plot of average global temperature in 2004, using data from public sources. Details about that construction and the data used are given at:
Population, Oil and Global Warming, 31 May 2019 (15 March 2004)
https://manuelgarciajr.com/2019/05/31/population-oil-and-global-warming/
10. The Anthropocene Epoch began sometime between October and December 1965.
https://manuelgarciajr.com/2018/02/23/the-anthropocenes-birthday/