Chapter energy and technology the enhancement of skin

6.9. The demographic transition

The early demographic history of Homo Sapiens was covered, very briefly, in Chapter 5, Sections 5.1 through 5.4. Human population in the Old Stone Age cannot be estimated with any accuracy but given the scarcity of evidence of habitation the numbers must have been small. The transition from hunting-gathering to settled agriculture began in the valleys of the Nile, the Tigris-Euphrates, and presumably the big rivers of South Asia and China, about 10,000 years ago. That was an indication of scarcity of game, probably due to population density. By 3000 years ago (1000 BCE) it had probably increased to 150 million or so (Figure 32). At the peak of the Roman Empire it might have doubled, as suggested by the several waves of “barbarians” seeking new lands to settle. A few moderately large cities existed in that time. But when Rome collapsed, the urban population also declined.

Figure : World population growth through history

Growth was slow, barely keeping up with land clearing (the fertile river valleys having been settled long since) until the devastating bubonic plague in the 14^th century, which killed between a third and a half of the population of Europe and presumably elsewhere. The labor shortage following that plague resulted in higher wages and food prices in Europe. It also gave the towns more leverage against feudal landowners, which accelerated economic activity and trade – and urbanization. The fall of Constantinople to the Ottoman Turks (in 1453) was a watershed, not only in Europe, because it cut the traditional “silk road” for trade with China and stimulated navigation, exploration and long-distance maritime trade instead.

Birth rates (children per woman) increased during the 15^th and 16^th centuries thanks to progress in reducing the death rates of young women giving birth in the absence of medical facilities or antiseptics. Early childhood death rates fell due to increased medical knowledge (e.g. about disease transmission) and simple public health measures. So population growth rates accelerated while death rates fell dramatically as illustrated for five countries (Figure 33). The decline in death rates in the 19^th century was mostly due to further progress in public health (e.g. water treatment and sewage treatment) and more effective antiseptics.

In the 20^th century the main factor bringing death rates down has been the conquest of infectious disease (like flu, smallpox and measles) by segregation, vaccination or (for bacterial infections) by sulfa drugs and antibiotics (penicillin and streptomycin). During the Napoleonic wars and the US Civil War, the vast majority of wounded soldiers died. Death rates among wounded soldiers fell somewhat during the Crimean War (thanks to nursing) and still more during World War I. The death rate for wounded soldiers fell dramatically during and after WW II, as medical help became available near the front lines (as illustrated by the TV series M*A*S*H.) Today doctors travel with the soldiers and the death rate among wounded soldiers is negligible.

So the declining death rate preceded the declining birth rate. Only recently have the two rates begun to converge in the most advanced countries. Indeed, birth rates are now below death rates in Germany, Italy, Japan and Spain, and Eastern Europe including Russia.

Figure :Demographic transition

Figure 34 shows the declining population growth rates in the world as a whole, as compared to the rates in less developed vs. more developed countries, while Figure 35 shows the global population growth since 1700.

Death rates have continued to decline thanks to medial progress but birth rates have also begun to decline, at least in the industrialized countries. The weakening of religious opposition to birth control, the availability of cheap contraceptives, and the high cost of raising children in cities are the major reasons. (Children are useful labor on small farms, but much less so, at least for households in cities.) However it is increasingly clear that the critical variable is female education. Females with primary education (or none) have many more children than females with primary or secondary education. Females with tertiary education have even fewer children, less than one child per woman. Yet a number of European countries (and Japan) are now subsidizing children, under the (false) impression that there will be a demographic crisis in the future: too few working people to support the elderly by means of their social security taxes. This child subsidy policy makes absolutely no sense for countries with youth unemployment rates of 20% or more. The global economy does not need more unskilled or semi-skilled labor supply, and even college-educated boys and girls are having trouble finding jobs. The social security problem needs to be addressed in a different way, perhaps by means of a guaranteed income or negative income tax. (Or it may not be solved at all.))

Figure : Recent population growth rates

A few years ago it was thought that the global maximum will be between 9 and 9.5 billion, sometime after 2050 e.g. {Lutz, 2004 #5868}. Recent revisions have suggested that the global population will reach 11 billion by 2100 and that peak will be later and higher, if there is a peak at all e.g.{Gerland, 2014 #7833}. It is not clear whether, or to what extent, relaxation of population policies (especially the 1-child policy in China) may have contributed to the shift in expectations.

Figure : Population of the Earth

However it is very clear that urbanization is one of the main factors contributing to lower birth rates. Lack of space, less demand for child labor (sadly, not zero) and the high cost of raising and educating children in cities are the primary reasons why birth rates are so much lower in the highly urbanized (developed) countries than in the more rural, less developed parts of the world. Urbanization for different parts of the world, with extrapolations to 2050, is plotted in (Figure 36).

Figure : Graph showing world urbanization for different world areas 1950-2050

Declining birth rates, in turn have a major impact on the social structure of countries, as shown in Figure 37. Countries, especially Muslim countries) like Egypt, Indonesia and Pakistan, with high birth-rates have very young populations. This young population is sometimes portrayed as an economic advantage, since it implies that there are many people of working age (yellow) to support the elderly non-working population (red).

Figure : Population age structure

But the young population (blue) guarantees a lot of future growth, even if birth rates slow down. Moreover, it imposes a heavy load on the educational system. (Many of the young boys in poor Muslim countries like Egypt and Pakistan end up in “madrassas”, which essentially teach nothing except memorization of the Koran.) It tends to lead to an under-educated class of young people with few job skills. These children become easy prey for religious fanatics, jihadists or criminal gangs. On the other hand, China’s unpopular “one child” policy has allowed that country to educate its young people, enabling China to become the manufacturing hub of the world. By contrast, countries like Japan and Germany with old populations have a different problem: namely too few tax-paying workers with jobs to support the large number of elderly pensioners (many with health problems).

Urbanization, in turn, is driven by the economics of specialization (Adam Smith called it “division of labor”) and economies of scale. The small self-sufficient farmer may be a social ideal for Jeffersonians who dislike the encroachment of “big government”. But that kind of farmer needs to be a “jack of all trades” whereas a large factory can hire specialists for many different functions. And in most enterprises, increased scale allows fixed costs to be spread over more output. It is an old story that productivity and incomes are higher in cities – hence in urbanized areas – than in the surrounding rural areas. The very sharp increase in GDP per capita after 1960, in almost all regions of the world, is partly attributable to rapid urbanization (Figure 38). Cities also offer greater variety of ideas, educational opportunities, job opportunities, housing and entertainment opportunities, not to mention choice of products for shoppers to buy.

Figure : Per capita GDP by region

The other reason for sharp increases in GDP per capita after 1960 is partly attributable to increased per capita energy consumption, especially of petroleum products (shown as green in Figure 39). This was mostly liquid fuels for aircraft, trucks, buses and private automobiles. The other big increase in per capita energy consumption since 1960 was of natural gas for a variety of purposes including electric power, space heating and petrochemicals (e.g. plastics).

Use of biofuels, mostly wood and charcoal (blue), is declining everywhere due to deforestation, and most of what remains is in less developed countries that do not have hydrocarbons. Coal consumption per capita is roughly constant (which means it is still increasing globally) primarily because of its importance for the iron and steel industry, the cement industry, and for electric power generation. Overall, there is no indication of declining energy consumption per capita.

Figure : Energy use per capita

It is worth mentioning (as shown by the graph) that per capita energy use in the US (and Canada) is much higher than in any other region: it is double the level in Germany and Japan, and five times larger than the world average. This fact suggests that there must be large opportunities for energy efficiency and renewables in the US and Canada. I will discuss some of them in Chapter 7.

1. The text on the Rosetta stone, in three languages (hieroglyphic, demotic and ancient Greek), was a decree by Ptolemy V, issued at Memphis and dated 196 BCE.

2^. The quantities were quite large. One province paid its annual tax by shipping 1.5 million sheets of paper to the central government.

359. The first silver coins were minted by King Pheidos of Argos, about 700 BCE. Croesus’ coins were made from electrum, an alloy of gold and silver. The Persians subsequently eliminated the silver and produced pure gold coins.

4^. Credit for farmers on a small scale for planting crops seems to have existed in some countries since Babylonian times, but the practice did not become a major source of profit and wealth creation until the middle Ages.

5. One of the tourist sites in Mycenea (supposedly the home of Agamemnon) is an ancient royal tomb, still in nearly perfect condition. Above the entrance is a lintel stone resting across two walls that weighs 120 tons (est.) How did it get there?

6. From 1850 till 1950 coal commanded more than 90% of British commercial energy use, wood having completely disappeared by 1870 {McMullen, 1983 #7715}.

7. By contrast, telegraphy got a slower start in the U.S., even though the system developed by Morse (with assistance from Joseph Henry and others) was technically superior and was eventually adopted in most countries. Morse's system did not achieve recognition until the U.S. congress appropriated money for a demonstration line between Washington D.C. and Baltimore. The demonstration took place successfully in 1844. Again, it was railroads that were the early adopters.

8^. The first hydraulic motors were undershot or overshot water wheels, going back to Roman times and perhaps even earlier. A French engineer, Bernard Forrest de Belidor wrote a monograph Architecture Hydraulique in 1757, describing alternative hydraulic motor design possibilities. The first enclosed hydraulic turbines, using a screw-type propeller, were built by Benoit Fourneyron in the 1830s. An improved design by Uriah Boyden and James Francis of Lowell, Massachusetts, the Francis reaction turbine in (1848) achieved 90% conversion efficiency {Hawke, 1988 #2338} pp.197-98. This design (not the turbine) is still in use today. Many factories, especially textile plants near fast-flowing rivers like the Merrimack River in Connecticut, used water-wheels for power well into the 19th century.

9^. Before Parsons the maximum rotational speed of dynamos was 1200 rpm. Parsons increased this in his first generator (1889) to l8,000 rpm.

10 . When the three biggest firms, Bayer, Hoechst and BASF consolidated (c.1925) they took the name I.G. Farbenindustrie. Farben is the German word for "color".

11^. The original producer was the Guffey Petroleum Company, later merged with the Gulf Refining Company, both financed largely by the Mellon bank in Pittsburgh. By coincidence, the Carnegie Steel Company was sold to JP Morgan (to create US Steel Co. about that time, and a number of Carnegie’s employees became instant millionaires. Several of them invested that money in Spindletop.

12^. The tool was described as “a rolling bit with two cones with unevenly spaced teeth” {Rundell, 2000 #7667}. It was patented by Howard Hughes Sr. and Walter Sharp. When Sharp died in 1913 Hughes bought his share of their business and renamed it Hughes Tool Co. in 1915. The Hughes Tool Company was the source of profits that created (among other things) Hughes Helicopter and Aircraft Co and, subsequently spun off a number of aerospace enterprises.

13^. The Standard Oil Trust was broken up by order of the US Supreme Court in 1911, creating a number of newly independent “children”, of which Standard Oil of Indiana was one.

14. The power stroke of an ICE is driven by the expansion of hot gases released by the explosive combustion of fuel. Since neither temperature not pressure is constant, the resulting free energy is some compromise between the Gibbs and Helmholtz versions.

15. Edison's success was bad news for the gas-light industry. After a long period of prosperous growth, gas shares slumped sharply in the late 1880's, which may have contributed to the recession of the early 1890's. As it happened, the gas-light system was temporarily reprieved by the invention of the "gas mantle" by Carl von Welsbach (1885). The incandescent thoria-ceria mantle increased the luminosity of a gas flame by a factor of a little more than 6 {Passer, 1953 #3992 p.196}, and its adoption kept gas lighting competitive for another 20 years. Actually 1910 was the peak year for gas-light. The electric light was adopted much more rapidly in the U.S. than it was in the U.K., primarily because gas was much cheaper in Britain, making electricity much less competitive for purposes of lighting in the 1890's. This, together with restrictive legislation, seriously impeded the British in developing a competitive electrical industry.

16^. Assuming a candle weight 1/6 of a pound producing 13 lumens burns for 7 hours.

17. However, in the mid-1890's the two firms were fighting hundreds of lawsuits over patent rights; this problem was finally resolved by creation of a patent pool which gave GE 63% and Westinghouse 37% of the combined royalties of the two firms for 15 years. It worked. The main benefit of this arrangement was that neither incompatible standards nor patent restrictions held back further technological progress in applications of electricity, as might otherwise have happened.

18. The Bell licensees gradually evolved into local operating companies. Western Electric Co. was acquired by American Bell in 1881 to become its manufacturing arm, and AT&T was formed to operate "long lines" interconnecting the local companies. It gradually acquired stock in many of the operating companies and subsequently exchanged its stock with that of American Bell, becoming the "parent". AT&T was broken up by the US Department of Justice in 1984, although the “long distance” component of the original conglomerate still exists as a separate telecom company, having first been swallowed up by one of its former “children”. After the breakup, Western Electric became Lucent, which later merged with the French firm Alcatel.

19^ Western Electric was later acquired by AT&T and became its manufacturing arm.