Energy utilized by a human as a subject of industrial civilization and as a part of nature.

By Yuri Magarshak and Eugene Levich January 8, 2005, New-York

It is estimated that the energy produced and utilized by the contemporary human civilization is comparable with that produced by human species biologically. It is only a fraction of the total energy produced and utilized by global biosphere. Somewhat against intuition this energy recalculated per one human, by order of magnitude remained the same throughout history, independently, on the level of technological development.
We often hear these days that it is only a matter of time before the human race will face a sharp shortage in energy supply. There is a perception of pending crisis amongst many in professional community. The modern industrial civilization totally depends on burning of fossil fuel, primarily oil and natural gas. Even though the available deposits of both these fossils are enormous they are not unlimited. Time should come when they will be depleted and even exhausted. And this time may be not so far away from now.
The burning of fuels in furnaces as a method for getting energy out of fossils doesnt exist in nature, or in vivo as we call it traditionally. It is a peculiar human invention. When the total population on Earth counted in millions and humans learned to burn wood in a controlled manner, for warming and cooking, protecting against predators; possibly, the greatest invention ever made by our species. Nowadays, that the population is 100 times bigger, and we burn colossal quantities of precious fossils with abandon, it would be a folly not to think of the consequences. Not only is the burning of fossils inefficient in comparison to the mechanisms of energy production in vivo, but it brutally pollutes the environment.
Consider the internal-combustion engine for instance. In essence, it is a crude, conceptually primitive technological contraption burning fuel in an enclosed space. Simple analysis of energy balances shows that the locomotive efficiency of internal-combustion engines is inferior to that of a horse or a flea. Increasingly sophisticated electronics and mechanics, and chromium-plated sleek shape of modern cars help to conceal the fact that the principal design of their engines has not fundamentally changed for over a century. The same is true for practically all methods of release of energy from fossils.
The beauty and superiority of natural mechanisms of releasing energy by means of fermentative catalysis and chemical energy utilization are too obvious. The fundamental energy in vivo is a result of vegetable and bacterial photosynthesis. It is preserved as an internal energy of glucose or its derivatives and is released, for instance, by means of adenosine triphosphate (ATP), or other chemical reactions. The efficiency of these processes is extremely high. There is no pollution or adverse waste.
Estimates for energy production and usage: extraction from fossils and in vivo
Perhaps, civilizations demand for energy extends so greatly beyond anything produced in vivo that perfectly clean natural methods of energy utilization are not possible. If this is indeed the case then we have no choice and will be compelled to deal with imperfect and dirty fossil burning until the day when they are finished.
With all PR around the progress of modern technology and inexorable growth of global industrial production, intuitively to some it may appear that the industrial civilization produces and uses far more energy than the human race does for existence as a biological species. We questioned a good number of our colleagues, scientists, engineers and businessmen, and found that such a viewpoint is widely spread. No doubt then it may play a role in political decision making, bearing upon the general direction of energy production development, thus having impact on the development of civilization as a whole. This is why it is important to learn with confidence whether this is truly the case. Moreover, it useful to study the issue using as few assumptions as possible and having faith primarily in uncontestable facts and common sense.
To this end, let us estimate the amount of energy produced by burning a typical organic fuel. A liter of oil, the most efficient organic fuel, yields about 3·107 joules. So, while burning 1 tone or 1 m3 of oil we may extract by order of magnitude about 3 1010 joules (we assume for simplicity that 1 liter of oil weighs 1 kg, which is not exact). Not more than a third of this energy is utilized inside internal-combustion engines and turbines by means of which we are using much of energy. Huge losses are incurred while oil (or natural gas) is pumped through pipes and other sort of energy sources transportation. Overall, a large amount of energy is spent to serve the giant infrastructure that enables the final delivery of useful energy to consumers. In this sense, it is safe to suggest that less than 1010 of useful joules per tone of oil are eventually delivered for direct consumption. About 5 billion tones of oil a year are pumped, which satisfies approximately 70% of the global energy demand. Consequently, having burnt all kinds of organic fuel we produce approximately 5 1019 joules of useful energy.
If we divide this number by the number of seconds in a year (about3 107) and get the power moving the world civilization to be less than 21012 W; or dividing this number by the total population of six billion (6109 ) we obtain an estimate of approximately 500 W for one (average) human.
For comparison, our sun radiates 4 1026 W. Only 5 10-10 fraction of the total energy radiated by sun or 2 1017 W, out of this number reaches the Earth, which is about 100.000 times more than the power of contemporary civilization.
Now, let us estimate the amount of energy, or power the human race uses as a biological species. The energy which is required to maintain metabolism in a person for a day (the energy which a person gets with food) is about 2500 kilo calories or 107 joules (1 kilo calorie is a little bit more than 4000 joules). We multiply this number by the number of days in one year, obtaining 3.6 109 joules. We then multiply the last number by 6109-the total number of humans- and get approximately 2 1019 joules. This is the total energy consumed by humans in order to sustain themselves as biological species; to be sure only slightly less than the amount of energy produced by modern civilization.
Consequently, the average amount of power which is needed to maintain a well fed persons life biologically is about 200 Watts, which is close by order of magnitude to the amount of power produced artificially by an average human.
Therefore, the amount of power needed to sustain the life of the human race as a biological species and the amount the human race produces are essentially of the same order of magnitude. As we promised above we arrived at this conclusion having used only very basic and well known facts, such as the total oil produced and the number of calories that a human consumes. The rest was just common sense.

From estimates to pondering over the res

What is it? Is it only a coincidence? Maybe the similarity between the power which a human as a part of the biosphere uses and that which a civilized person produces is an invariant? This invariant characterizes not so much the stage of the development of our civilization but Homo sapience as a biological species? To answer this question lets try to find out how much energy a person of the Bronze Age needed.
If several kilograms of firewood (the relative amount of energy produced by burning wood is twice or thrice less than that of the oil) were burnt in 24 hours then it gave 107 joules for a person. This means that a human from the primitive civilization also used 102 103 W. This amount of power doesnt greatly differ from that which an average person in our times produces and is pretty much the same as the energy needed to maintain metabolism. This figure was quite the same in the period of antiquity, in the Middle Ages and during the Renaissance.
The difference in the amount of energy between economically developed countries and the developing countries doesnt change the average estimate. It is likely that the gap in energy production and consumption between rich and poor in the antiquity was not less. Roman Caesars didnt use less energy to light up the palace on Palatine Hill than nowadays they do on Capitol Hill. Notorious scientific and technological progress didnt change this disparity.
So this figure quite surprisingly remains the same in the human society when calculated per average human, at least by order of magnitude, and it seems to characterize the Earth civilization as such, but not the level of its development; the striking feature of which is the growth in waste and pollution of the environment as a result of the global growth of energy production.
In comparison with the production of energy in vivo by bacteria, seaweed and green leaves of plants, that leaves no waste and is self regenerating, the industrial civilization burning precious fossil fuels with frenzy, looks clumsy. Just to remind, the fossil fuels deposits have been created by natural processes in the course of millions of years. In a way these fossils can be seen as storage of the energy of sun. At the rate of their exploitation as we have nowadays they can be exhausted within a short time span. Clearly, we can conclude that all modern methods of producing energy by burning fossils are inefficient, polluting the environment, in other words extremely barbaric.

The conclusions unexpected and instructive

The conclusion seems to be quite unexpected and contradicting intuition.
Which part of the biosphere of the earth do people use? 6 billion people weigh about 500 million tones. The weight of food a person eats during one year is several times his weight. Six billion people consume several billion tones of food. The whole biosphere of the Earth weighs, dependent on different assumptions by different authors, 1012 1013 tones. Moreover, a considerable part of it reproduces annually (micro-organisms reproduce much more often). The truth of the matter is that the energy the human race uses is insignificant not only in comparison with the energy of sun but also in comparison with the energy produced and utilized in the biosphere.
The conclusions are:
       The human race produces far less energy than that which is produced in vivo to maintain the life of different organisms, which are connected with each other in a food pyramid, with Homo sapience on the top of it. Surprisingly, when recalculated per one human this energy remains invariant in time by order of magnitude at all levels of technological development
       The total power used and produced by civilization is insignificant in comparison with the power of the sun energy being transformed by plants and bacteria. These conclusions can be useful not only for professionals (ecologists, doctors, scientists in various disciplines) and inquisitive people, but also for politicians, financiers and industrialists whose decisions bear on the paths of development for our civilization.
Life has been on Earth for more than 3 billion years, leaving almost no waste. The human race, quite on the contrary, swiftly destroys the environment, threatening the very existence of life on Earth (including its own existence as a biological species).
Pollution growing everywhere, in the atmosphere, ground and water is due to a large extent to the means of energy production. In contrast, the energy of the world industry is insignificant in comparison with the flows of energy in vivo.
As a result, there comes an obvious conclusion out of rather unexpected observations: the human race should try and learn from nature how to utilize the energy efficiently and less wastefully. In particular, it seems unthinkable that solar energy cannot be harnessed and used on a much vaster scale than it is done now. In order for the human race to survive as a part of a biosphere and prosper as the creator and master of industrial civilization it should be better sooner than later.
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