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Archive for Agosto, 2018

Norman Pagett

 

Humankind evolved out of a hunter-gatherer past, using stone, fire and then metals to survive in a harsh yet sustainable environment. Although they had no concept of it, their existence was self-sustaining and energy-balanced. All physical effort was expended in catching food and basic survival, which left no energy surplus. Without energy surplus there could be no specialization, no society and no economy.

This is why the Inuit don’t built cities and mobilise armies to invade south.

All the bright whirry things that make up our current version of civilization, and the fact that we have full bellies, pretty clothes, warm houses and the ability to defy gravity fosters the delusion that we have progressed beyond that era.

We haven’t.

We face our ‘modern’ world still under the control of the survival instincts that were honed to perfection over millennia to cope with hazards and problems that faced our ancestors in a different age. Their dangers were real and immediate, to be dealt with on the instant. They could not concern themselves with that which might happen next week or years hence. Our prehistoric forebears were too busy sourcing sufficient energy for their living day, which was locked into the bodies of dangerous animals who were unwilling to surrender it.

Thus the skill of the hunt became paramount to get sufficient energy to survive and breed. A female offered herself to the best hunter, because that gave her offspring the maximum boost to chances of survival. Crude perhaps, but the forces of nature take no account of civilized niceties.

Successful hunters killed and consumed, lived and procreated; unsuccessful ones did not.

So we are the progeny of success: they are us, and we are they. Within us we carry the mindset of our ancestors.

But nature still cares only that we survive the present, and our hunter gatherer instinct concurs; in evolutionary terms, action on a threat that is not imminent is a still a waste of precious energy, the fact that we have a surplus is taken as confirmation that we need do nothing, because there will always be more. That is why we perceive the dangers of climate change, overpopulation and energy depletion and our other potential problems as being beyond our event horizon, so the majority of us obey primitive instincts and ignore them.

We burn our fuel to sate immediate needs because we can. Supermarkets are full, fuel pumps work and light remains available at our fingertips. These are now our energy sources and our legacy instinct tells us they will always be available, so why should we disbelieve those who cry ‘hoax’?

The complacency of surplus

Despite the trappings of our consumer society, our main preoccupation is still that of procuring sufficient energy to sustain our lifestyle at its current level, and fulfill promises of growth. Oil, coal and gas enable our existence so we tear the earth apart to get more.

In the early 1800s, the industrial revolution gave an enormous boost to our survival chances as we released the unprecedented amount of energy locked in coal oil and gas. Surplus energy was bestowed on mankind as a once-only gift. And though we were not intelligent enough to see that, it allowed us to maximise our consumption at every available opportunity for the next 250 years.

The development of the heat engine gave leverage to the labour of the minority, allowing them to feed the majority.

For the first time in history much of the world’s population was freed to take employment other than that of food sourcing. Now a 500 acre farm can be run by half a dozen workers instead of 100 and deliver many times more food. This has not been due to our innate cleverness, but the burning of hydrocarbon fuels which provided cheap food surpluses to support extra people, and the means to employ those people in the context we know today: manufacturing, medicine, teaching, the arts and thousands of other professions that are now essential to the society we live in. Hydrocarbon processes also form the basis of all the tools and transport we need in our job-functions that make our living possible, together with the houses we live in.

Our dependence on oil, coal and gas is now absolute, and there are no meaningful substitutes. Windfarms and solar panels deliver electricity, but the complexity of human civilization has been built on the input of hydrocarbons. The energy output of a wind turbine and a barrel of oil is not interchangeable to the extent necessary to support any working infrastructure that would relate to the one we have.

We have enjoyed the benefits of fossil fuel energy for so long that we take it all for granted. Such complaisance has become another part of our perceived infinity. Without blind faith in that infinity of supply, our industrial infrastructure would collapse. So the legacy instinct kicks in again, allowing us to hold onto the delusion that supply really is infinite.

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Supplemental energy puts humans in charge

Energy is a subject that is greatly misunderstood. Its role in our lives is truly amazing. We humans are able to live and move because of the energy that we get from food. We count this energy in calories.

Green plants are also energy dependent. In photosynthesis, plants use energy from the sun to convert carbon dioxide and water into the glucose that they need to grow.

Ecosystems are energy dependent as well. The ecologist Howard T. Odum in Environment, Power, and Society explains that ecosystems self-organize in a way that maximizes the useful energy obtained by the group of plants and animals.

Economies created by humans are in some respects very similar to ecosystems. They, too, self-organize and seem to be energy dependent. The big difference is that over one million years ago, pre-humans learned to control fire. As a result, they were able to burn biomass and indirectly add the energy this provided to the food energy that they otherwise had available. The energy from burning biomass was an early form of supplemental energy. How important was this change?

How Humans Gained Dominion Over Other Animals

James C. Scott, in Against the Grain, explains that being able to burn biomass was sufficient to turn around who was in charge: pre-humans or large animals. In one cave in South Africa, he indicates that a lower layer of remains found in the cave did not show any carbon deposits, and hence were created before pre-humans occupying the cave gained control of fire. In this layer, skeletons of big cats were found, along with scattered gnawed bones of pre-humans.

In a higher layer, carbon deposits were found. In this layer, pre-humans were clearly in charge. Their skeletons were much more intact, and the bones of big cats were scattered about and showed signs of gnawing. Who was in charge had changed.

There is other evidence of human domination becoming possible with the controlled use of fire. Studies show a dramatic drop in numbers of large mammals not long after settlement by humans in several areas outside Africa. (Jeremy Lent, The Patterning Instinct, based on P. S. Martin’s “Prehistoric overkill: A global model” in Quaternary Extinctions: A Prehistoric Revolution.)

In recent times, humans have added fossil fuel energy, hydroelectric energy and nuclear energy to their “toolbox.” All of these energy sources have allowed humans to stay in charge.

Whether humans’ control of energy is good or bad depends on a person’s point of view. Without humans being in charge, the human population would likely be similar in size to that of the populations of chimps or gorillas–in other words, tiny in comparison to today’s human population. Furthermore, humans would be located only in the warmer parts of the world. As we will see in the next section, humans would not have evolved in the direction they did. Instead, they would have continued with only the abilities they had as pre-humans. They would have continued living in the wild, eating raw food and spending half of the day chewing it.

How the Controlled Burning of Biomass Produced Amazing Results 

Pre-humans learned to control the burning of sticks and other biomass over one million years ago. This new-found ability helped our ancestors in many ways:

(1) Pre-humans could cook part of their food. (Richard Wrangham, Catching Fire: How Cooking Made Us Human) The ability to cook food increased the variety of food that could be eaten because some foods need to be cooked to be edible. Chewing time could be greatly reduced (Chris Organ et al.), leaving more time for tool making. Moreover, cooking allowed nutrients in food to be better absorbed.

(2) Less of the energy from food was needed for the maintenance of large teeth, jaws, and guts. Instead, more energy could go into building a larger brain. In this way, our ancestors could outsmart their predators, instead of depending on their muscles and teeth.

(3) Pre-humans could use fire as a tool to burn down unwanted trees and bush, making it  easier to capture prey and encouraging new plant growth of a type more suitable as human food. Also, the fire itself could be used to frighten predators.

(4) Stone tools could be made sharper using heat.

(5) The heat from fire could be used to enlarge the range where pre-humans were able to live.

(6) Larger brains and frequent gatherings around campfires allowed language to develop.

(7) Humans, with their larger brains, were able to selectively breed different types of plants and animals, choosing characteristics that were better suited to their needs. As humans tamed fire and animals, they themselves became (in some sense) tamer.

The Physics Reason Why Energy Is So Important

We are all familiar with how the energy from food allows humans to grow. We also know how solar energy allows green plants to grow. Most physics instruction focuses on thermodynamically closed systems—that is, systems to which no new energy supply is added. Sometimes isolated systems are discussed—again a situation where no additional energy is available. In these situations, there is no growth—only a gradual depletion of the available energy supply, leading ultimately to “heat death.”

More recent analysis has shown that thermodynamically open systems, which are characterized by inflows of energy, are very different. They can, and do, change and grow. Hurricanes grow when heat from warm seawater is available. Stars grow as the result of the chemical reactions taking place within them. All of these structures (known as dissipative structures) are temporary in that they cannot continue to exist when suitable flows of energy are no longer available. They can also be undone in other ways, such as too much pollution or by other forms of “entropy.”

On earth, the energy system we experience is an open system. Energy from the sun is constantly being supplied. Energy made available by burning biomass and from burning fossil fuels is also being supplied, as is nuclear energy, in the form of electricity. The energy obtained from burned fossil fuels, in fact, reflects the re-release of ancient solar energy that was once stored in the bodies of small plants and animals. Under the proper temperature and pressure conditions, this stored energy had been slowly transformed into fossil fuels.

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