Monthly Discussion



Energy Crisis and Women痴 Fertility


Today I want to take issue with arguments presented on Friday, 13 February, 2004 in the World edition of the BBC News.

That Friday Virginia Abernethy told a Seattle meeting that as the world's reserves of oil and gas run out over the coming decades, the birthrates of societies are likely to fall considerably. She said that the loss of fossil fuels would hit world economies very hard. 摘conomic hardship discourages people from marrying young and from having closely spaced children, she said.

The anthropologist and professor emeritus of psychiatry from Vanderbilt University was speaking in Washington State at the annual gathering of the American Association for the Advancement of Science.

典he availability of energy has been a major factor in population growth, said Professor Abernethy. 的n the modern context, energy use per capita affects economic activity. So a prolonged decline in energy use per capita will tend to depress the economy which, in turn, will cause a decline in the fertility rate.

Professor Virginia Abernethy is an author and expert on 泥emographic Transition theory. Now why would I like to challenge the statements of such a qualified individual? The answer is that I trust more the laws of nature than people痴 opinions no matter how qualified individuals they may be.

Let us begin with her opening statement. The world痴 reserves of oil and gas are in no way going to run out over the coming decades. Society moves from one type of primary energy source to the next for reasons more profound than scarcity. Such reasons are: energy content (in terms of hydrogen molecules per kilogram), distribution grids, technology, economies of scale, and so on. But not because the reserves run out. We never ran out of wood and yet we moved to coal. We never ran out of coal and yet we moved to oil.

Exhibit 3 shows that the oil discovery curve has always followed the oil production curve with ten years delay. It proves that we are discovering oil reserves in response to the amount of oil we consume. Therefore, oil discovery is a consequence of production not a cause for production. No argument can be made for running out of oil. We are simply moving away from oil and toward gas mainly because one kilogram of gas has more energy in it than one kilogram of oil!


Oil Discovery Triggered by Oil Production

Exhibit 3. At all times the level of oil production preceded the level of oil discovery by 10 years. Both growth processes conform faithfully to natural growth patterns (S-curves). The graph is taken from PREDICTIONS.


Abernethy痴 second argument for a prolonged decline in energy use per capita is only partially valid. Exhibit 4 shows the energy consumption per capita worldwide and even if we are still in a stagnating period right now, there is no systematic long-term declining trend. In contrast, the last 150 years (and Kondratieff痴 cycle) argue for an imminent upturn on this indicator.


Energy Consumption Worldwide on Imminent Rise

Exhibit 4. Data and S-curves on two Kondratieff cycles for energy consumption worldwide. We are on the verge of a new growth phase. The intermittent S-curve is a scenario suggested by 150 years of history. The graph is taken from PREDICTIONS.

Let us consider now the growth of the world population. Exhibit 5 shows that during the 20th century (the lion痴 share of the growth process) world population followed a natural growth process quite precisely. A natural growth process proceeds to completion under natural conditions. No niche in nature was ever left half empty under natural conditions. In our case, natural conditions are defined as the conditions that prevailed during the historical window over which the S-curve has been established. Energy hardships have certainly been among the phenomena witnessed during the 20th century. There is no a priori reason to believe that in the next few decades there will appear never-seen conditions so as to make the evolution of the world population deviate from its natural course.


World Population Has Long Been on A Natural-Growth Course

Exhibit 5. Data (blue line) and S-curve (purple line) for world population. The agreement is excellent. The projection is guaranteed under natural conditions (like those that prevailed throughout the 20th century). The data come from a compilation of different sources.*


A for women痴 fertility, it has been going down for some time now. Exhibit 6 shows the decline of the number of children American women have in their lifetime from 7 to 2 over the last 200 years. It could well signify another 渡atural-growth process, this time an upside down S-curve. A notable deviation is visible after World War II and reflects the familiar baby boom. The trend of the purple line points to a further decline reaching 1.4 by 2050. But this decline is not what Abernethy has been talking about because it has nothing to do with energy shortages. In the long term childbearing is way too important a human function to suffer from lesser causes such as the lack of heating. People will never let themselves be strangled on the energy sector. If need be, we will produce all the energy needed via nuclear processes.


Fertility of American Women

Exhibit 7. Total number of births per woman. The purple line is a downward pointing S-curve. The data come from U.S. Bureau of the Census, HISTORICAL STATISTICS OF THE UNITED STATES, plus others.*


Abernethy may have been speaking about only to the very near future. After all, short-term deviations from natural trends can take place in both energy consumption and women痴 fertility. But depending on how short the timeframe is, an energy shortage could trigger a rise rather than a decline in fertility! Lack of heating induces couples to cuddle-up in bed. Do you remember the mini baby boom following the New York City blackout in 1965?

* http://www.census.gov/ipc/www/worldhis.html

* http://www.eh.net/databases/uspop/uspop.txt