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Man lives in balance with other species in a world that has certain limits. In this world, it’s impossible to achieve the immutable, once and for all the established ratio – for every biological species there are periods of growth and decline populations.
Some species may dominate for some time, then others become dominant. If the species are close to each other in their “capabilities”, then such “ups and downs” are usually not very significant.
If a predator depends on a certain type of prey, then it cannot be eat the whole population, because after that it will be doomed to starvation death.
If you depict changes in two populations graphically, then it’s clear that they are constantly changing direction – up and down, as, for example, in this graph:
Figure 2. To illustrate changes in population size predator and prey used the model Trays – Voltaire. On this the graph shows the situation when these changes are not too significant
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In fact, often the number of populations exposed is much more significant changes, as shown in the following example. IN at the beginning of the study period, the number of baboons is 80 individuals, and the number of cheetahs – 40 individuals:
Figure 3. Trays – Volterra model used for demonstrations of a situation starting with 80 baboons (green line) and 40 cheetahs (black line)
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If species develop in parallel, then the natural balance between populations remains at approximately the same level. But if predators suddenly find another, better source of nutrition (you can call it source of energy, since food supplies the body with energy), then the population size of prey can increase dramatically.
For example, a yeast can process sugar from grape juice, turning it into alcohol. Yeast population on time increases and then decreases as the source disappears food, and from alcohol the fungus dies. Or the bacteria may multiply in the human body, if it finds what is necessary for itself nutrition, and the body’s defenses do not work enough effectively.
Often, an example with deer population of St. Matthew’s Island, where on the rocks grew abundantly lichen. An overgrown deer population began to eat lichen with faster than he was growing. At some point, the lichen is completely no more, and the deer population curve also plummeted.
Figure 4. Changes in the number of deer herds on the island St. Matthew, according to a study by David Klein from University of Alaska
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The deer example is similar to the sharp bends of the graph. predator prey. Deer ate renewable food faster than he could play. The island was a bit other food sources for animals, so some of them managed to survive, but still the decline in the population was very sharp.
Recently, the number of people has changed very substantially:
Figure 5. Data on human population changes were taken from the Atlas of World History by Makeyvedi and Jones, 1978
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A sharp increase in numbers coincides with the period of production and use of fossil fuels and begins in the early 19th century. However, if we look at an even earlier period of time, then see that growth has been observed over a very long period. Man learned to use fire more than a million years ago. A starting from 75 thousand years BC, the growth of human numbers has become pretty stable:
Chart 6. The growth of human population as they master new sources of energy. Horizontal – the number of years to date time, vertical – population size. From left to right: fire control, farming, global development deposits fossil fuels
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The first significant population growth occurred when a person learned to burn biomass and use the resulting fire to having to cook, bask, improve tools from stone and scare away predatory animals.
All this allowed our ancestors to populate new territories. globe, simultaneously destroying many species of animals. Biologist and paleontologist Nils Eldridge believes the first of six periods mass extermination of animals began when the first people began widely distributed in different parts of the world about 100 thousand years ago. The second phase began about 10 thousand years ago, when mankind has taken up farming. Even in these early stages the energy used by people allowed them to increase their number due to the reduction of populations of predatory animals.
Between 1 and 800 years of our era, a temporary attenuation of population growth (Fig. 6). This period is many disasters in different places of the planet, so growth in one the region was balanced by a decline in another.
Man has found a new resource for food – people have learned to clear the earth from trees and irrigate it. But over time, as population growth, available resources were distributed. Around the same time, they began to deplete. Earth is no longer gave the previous harvest. The pay that workers received fell, and it became more difficult to feed. Epidemics have begun. Graphically period such a decline can be represented as follows:
Figure 7. A typical long cycle graph economic activity, built according to Peter Turkin and Sergei Nefyodov: growth – 100+ years, stagflation – 50-60 years, crisis – 20-50 years, transition period
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So even in the period from 1 to 800 AD The population was not stable. In fact at this time in in different places of the planet there was either an increase or a decrease number so that the total number of people on the planet at this time did not change significantly.
Angus Meddison analyzed GDP growth from the 1st to the 1000th century of our era. He concluded that per capita GDP is slightly decreased at the end of this period (453) compared with the beginning (476). According to his calculations, the state of the economy from 1 to 800 AD was quite stable (with a lot of disasters), taking into account the lack of growth in population and GDP per capita population.
In the periods of history closer to us, people managed to master new energy sources (including peat moss, windmills and water mills). Well-equipped ships capable of transport people to new lands, form colonies and develop farming in new places, extracting resources and transporting them to your country.
Since 1800, thanks to an increase in fossil fuel production, there was a sharp jump in the number of people and a significant increase level of his life.
Figure 8. World energy consumption in year per person (blue – biofuel, red – coal, green – oil, lilac – natural gas, blue – hydroelectricity, orange – atomic energy)
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Is it possible to achieve a stable state, and how way?
There are not many options:
1. If you return to a period when our ancestors have not yet learned use fire, 100 – 200 thousand of us could live in warm climate, eat raw food and live about the same life as today live baboons or chimpanzees. In this case, a population of people probably would fluctuate within certain limits.
Nowadays, human internal organs have adapted to cooked food, and how they would react to full raw food eating is not entirely clear. However, it is possible that life in areas with an abundance of soft food (berries, fish) would be tolerable. Besides Moreover, the climate must be warm so that we do not freeze without fur coats. For these conditions to be met, the population must be even less.
2. Lack of people in general, strictly speaking, can also regarded as a steady state. However unlikely the prospect of such stability may suit any of us.
3. If we did not strive for globalization and ceased to produce new energy reserves, then the situation could be leveled local shocks like those that occurred from 1 to 800 AD This would also be a kind of steady state. However in our global world problems move easily from one part light in another.
4. If we want 7 billion people to continue to live, we need to provide them with a supply of energy, at least at the very elementary level. Assuming Survival today’s person needs energy consumption at least by level of 1820 (judging by the data shown in Fig. 8), then at each person must have at least 22 gigajoule. This is approximately 7 percent of today’s consumption. That is, we would have to do without transport, electricity, plumbing and sewage, so for us it would be a huge step back.
Even with the energy level of 1820, we still would have to partially use fossil fuels because there are too many of us, and biofuel alone would not be enough (Marked in blue in Fig. 
In addition, renewable sources, including modern hydroelectric and solar panels are also manufactured and transported by fossil fuels. Therefore, for using what we see today as renewable we must continue to mine fuel.
Plus to all of the above, we must will be:
(a) reduce population growth
(b) prevent the use of the energy reserves available to us (over designated 22 gigajoules per person) and achieve cardinal changes in lifestyle.
Often as a measure to keep population growth Earth within a certain framework, measures such as raising level of education among women and more opportunities to control over fertility. Unfortunately, these measures are also related to consumption. energy. In the conditions in question, a woman will have to morning to night to work in the field, and she simply does not have education time left.
Some crops manage to maintain population levels. within a certain framework by means not related to consumption of additional energy. In China, for example, strict birth control is set on top. In other countries there are cultural and religious restrictions – delaying marriage, for example, or long-term breastfeeding.
It’s even harder to keep people from using affordable energy sources and change their lifestyle. Limited to 7 percent of the energy that a person has consumed so far, would mean losing almost everything he was used to.
There is a common misconception that the refusal of personal transport can significantly affect the total amount consumed energy. In America, for example, gasoline accounts for about 44 percent of oil consumption. If we subtract this resource from the total quantities (including police cars, ambulances and delivery of goods), then we get a savings of only 16 percent. IN the rest of the world where not everyone has a personal car, saving there will be even less – an average of 10-12 percent.
Should we strive for a sustainable state economics?
At present, apparently, we are moving towards demographic collapse since human population growth has long been not comparable with the growth of populations of other species. Also today at we have many other restrictions, including the cost of mining oil, fresh water availability and air pollution.
The only steady state that would make sense is if humanity could voluntarily retreat in its development back to some lower level – as an alternative to collapse. TO Unfortunately, it’s hard to even imagine how to do this. Sole in history a period of relative stability – between 1 and 800 years AD, when the growth of a human population in some regions is a place balanced by a decline in others. Periods when growth there was no population at all, apparently, did not exist.
If, after the collapse, civilization slides to a lower level (but not to zero), it will most likely repeat the same model development over and over again. The man will build up again and population size, and consumption of available resources. This system is embedded in our instincts and it seems to struggle with it useless.
Whatever we do, sooner or later, collapse will inevitably happen, and humanity will slide to a lower level of its development.
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