Space Settlement: ORBITAL MOON MARS
ASTEROIDS ROADMAP L5 NEWS NASA
Colonies in Space
Copyright 1977, 2007 by T. A. Heppenheimer, reproduced with permission
Chapter 14: The Next Million Years Sir George Darwin, son of the famous Charles, predicted that our present era would be seen as a golden age compared to the vistas of famine and poverty which would follow in times to come, as Earth's teeming billions fought over its waning resources. Darwin echoed the classic arguments of all neo-Malthusians envisioning mankind's fate in terms of human procreation in a finite world. However, he did suggest that the situation would at least be improved, perhaps even solved, granted two prerequisites: population control and an inexhaustible energy source. Somewhat similar views had been expressed by H. G. Wells in his 1914 book The World Set Free, in which he predicted the development of the atomic bomb.
We will take quite a different view of the long-term future. Barring a catastrophic epidemic of human stupidity, the decades ahead are likely to see the foundations solidly laid for a world without large-scale poverty or hopelessness, a world of opportunity, rising living standards and widely shared middle-class levels of affluence. Such a world will endure into the indefinite future. It will not be without problems or difficulties and there will continue to be challenges aplenty; it will not be a utopian dream of equality and selflessness. The world of the next century will be one in which most people live at least as well as in today's America or Europe.
Such a world will not be achieved easily, for it will be necessary to solve such difficult problems as the population explosion. It is no mere neo-Malthusianism to be concerned 178 about the rapid growth of world population, for it can seriously delay the improvement of living standards over much of the world, and it is necessary to be aware of its actual nature. Mere projections of current growth rates will not do, nor will predictions that within a few centuries the world will resemble Yankee Stadium during the World Series. These fancies come from people who are not prepared to consider what enters into that intimately personal matter, a couple's decision to have a baby, but who do know how to use the log-log scales on a slide rule.
As is true with so much of this planet, there is no "world" population. It is much more useful to speak of the developed nations and their populations, as distinct from the underdeveloped ones. The developed countries include the United States, Canada, and most of Europe as well as Japan, Israel, and the Soviet Union. There are 31 in all, according to the population analyses of Charles F. Westoff of the Princeton University Office of Population Research. Together they account for 27 percent of the world population.
It appears that a simple statement can be made which characterizes the problem of overpopulation or too-rapid population growth in the developed countries: It is not a problem.
In the United States in recent years there has been a sharp falloff in the rate of childbearing. The rest of the developed world, less well known, has generally had a similar decline. To achieve zero population growth it is necessary that, on the average, women have 2.1 births in their childbearing years; each generation then will replace the next. In 1973 in the 31 developed nations, the corresponding figure was 2.2. In 20 of the 31, including the United States, Japan, and much of Europe, the rate is close to or below 2.1 and population trends are in the same direction in most of the remaining 11 countries. Only Spain, Portugal, Ireland, and Israel still have rates much above 2.5.
The currently low rates do not mean that zero population growth is around the corner. Populations will continue to grow for a few more decades because most societies still have proportionately more younger people in their childbearing years. However, there is little prospect of returning to higher rates of birth. In a number of developed countries, recently married women have been polled to find how many children they wanted or expected to have. The answers ranged from a high of 2.2 in the 1972 survey in the United States to a low of 1.8 in England.
The long-term prospect for the developed world seems to be similar to what France has experienced for the past two centuries. At the time of the French Revolution, its population of 25 million made France the most populous state in Europe. It easily stood off invasion by a coalition of powers determined to overthrow the Republic, and under Napoleon proceeded to a career of conquest. But in all the nineteenth century, its population grew by only 12 million. Germany quickly surpassed France, with unfortunate results for the peace of Europe. Today, at 52 million, France has maintained an average growth rate of only 0.4 per cent per year since 1789.
In the underdeveloped countries, the situation is very different. The population is truly exploding. In Latin America, in the early 1970s, the population grew at 2.7 percent per year, so it would double in 26 years. In Africa the rate was 2.6 percent, and underdeveloped Asia, excluding China, grew at 2.4 percent. China, which may be beginning to control its population growth, may have grown at 1.7 percent.
These extraordinary rates apply to nearly three-quarters of the human population. They do not result from recent large increases in the birth rate, quite the contrary. Birth rates in the underdeveloped world have been steady in recent years or, in some countries, begun to decline. What has happened is the introduction of modern medical techniques which have controlled many diseases, reduced infant mortality, and increased life expectancy. The falling death rates, unaccompanied by comparable reductions in the birth rate, have produced the resulting rapid growth.
This situation will not continue indefinitely. It results from the lag between the drop in death rates, which can be achieved through technology, and a drop in birth rates, which requires profound social changes. Longer life is recognized as desirable in all societies, but high fertility also has usually been regarded as desirable. It is the change in the latter viewpoint which takes time to accomplish and which produces the lag. However, there are several influences which in time can change people's views of the advantages of children and reduce the birth rate to a more manageable level.
A powerful incentive in reducing conceptions is people's unwillingness to accept a lowering of their accustomed standard of living. In nations like India this may be the most important influence. In many underdeveloped nations, however, programs of development have begun to raise the standard of living. In these societies people begin to find it possible to acquire bicycles or other consumer goods, to provide a better life to children already born, or to raise their status in society. Their chances of doing these things are often powerfully increased by having fewer children.
Overall, there will be continued and growing influences promoting reduction in the birthrate, while influences of old ways of living will tend to keep it high. Their power cannot be discounted but with the rapid pace of change in today's world, the universal desire for development and for better living standards, it can scarcely be doubted that the underdeveloped world also will achieve population control. But before the current population boom runs its course, the population of the underdeveloped world will quite likely double and then double again, during the next century or so.
[Footnote by author: In November 1976, new population growth rates and projections were made available. Lester Brown of the Worldwatch Institute stated that the overall world population growth rate, 1.9 percent annually in 1970, had fallen to 1.64 percent in 1975. The 1976 world population of 4 billion, which had been projected to grow to 6.3 billion by the year 2000, now is projected to reach only 5.4 billion. These results were attributed to the success of birth control programs in the developing nations; in particular. China's birth rate, 35.5 per 1000 of population in 1964. had fallen to 14.0 by 1975. While subject to subsequent revision, these findings constitute a major piece of new evidence tending to support the optimistic views of this book.]
This raises the question of feeding the hungry masses. According to Roger Revelle, director of Harvard's Center for Population Studies, the earth's arable land can probably provide food for 40 to 50 billion people. However, this would happen only if the land were tilled using the advanced methods of Western agriculture. It is a prime goal of many developing nations to bring agriculture to something like that level; but to do so will not be easy. When one compares the combines and agricultural extension agents of Iowa to the bullocks and night-soil gatherers of China, the room for improvement is evident. It is not likely that there will be massive widespread famines which will depopulate whole countries. However, there will continue to be temporary local or regional food shortages. These will no more control the long-term future of humanity than the famines of pre-revolutionary China influence the present situation, where China is nearly self-sufficient in food. But such shortages will involve considerable human suffering.
The picture which emerges is of a developing world in which population is not a problem, together with an underdeveloped world in which large population increases will take place before control is finally achieved. However, in a world of independent nations, each country tends to reap the advantage and experience the disadvantages of whatever population policy it adopts. While the decades ahead may see famine and hunger, these will spur internal reform in the affected nations far more certainly than they will lead to the destruction of the world as we know it.
But population control is only one of the requirements for a worthwhile human future. There must be enough resources to maintain a high level of industrial activity. NeoMalthusians argue that the resources of Earth are finite and will soon be exhausted, thus leading to a collapse of industrial civilizations. The alternate viewpoint is that most essential raw materials are practically inexhaustible in supply; that as we exhaust one raw material we can turn to lower-grade substitutes; and that eventually society can function using only renewable resources and elements such as iron and aluminum, which are abundant in the earth's crust. This latter viewpoint appears to be the proper one, and the neo-Malthusians appear to have been misled by their penchant for lumping all resources together without regard to their importance, ultimate abundance, or substitutability.
According to Alvin Weinberg and H. E. Goeller, of Oak Ridge National Laboratories, the world use of nonrenewable resources in 1968 totaled some 18 billion tons. Of this the percentages represented by individual resources were as follows:
Hydrocarbons, 66.60
Sand, 21.17 Limestone, 8.15
Iron, 1.45 Nitrogen, 0.68 Oxygen, 0.45 Sodium, 0.45 Chlorine, 0.45 Sulfur, 0.23 Aluminum, .072
Phosphorus, 0.07
Potassium, 0.07 Manganese, 0.028
Copper, 0.022 Zinc, 0.016 Silicon, 0.011 Chromium, 0.007
Lead, 0.003 Nickel, 0.002 Titanium, 0.0002
Tin, 0.0002
Some of the metals are in short supply but can be replaced by substitutes. Electrical copper can be almost entirely replaced by aluminum; structural copper and brass are largely replaceable by steel, aluminum, or titanium. Chromium is used in making stainless steel, which for most uses can be replaced by titanium. Lead, principally used in pipes, can be replaced by plastic or plastic-bonded steel; the same is true for zinc (galvanized iron) and tin (tin cans). [Footnote by author: It is true that plastics are currently made from scarce oil or natural gas. However, plastics are so valuable that in the future it will be profitable to produce them from shale oil, deeply buried coal, or even carbon extracted from limestone. That is, sources of carbon or hydrocarbon. too costly to exploit for energy production, will not be too costly to exploit as raw materials for use in making plastics.] In any case the minor metals are so small a part of the resource picture that they could increase in price manyfold and the overall economy would easily absorb the cost.
It is necessary to consider what present or prospective resources exist for the most extensively used materials and how long they may last. An indication of the latter is the ratio of the total resource to its 1968 rate of use, shown in the accompanying table.
The surprising and significant conclusion is that with three exceptions all of the most extensively used elements are available, in reasonable concentration, from resources which at 1968 rates of use would last for millions of years. Moreover, in extracting metals from these
resources, aluminum from clay requires only 1.28 times as much energy as from bauxite; iron from laterites requires only twice the energy as from high-grade ores. Society can turn to these resources with little or no loss of living standard and would be based largely on glass, plastic, wood, cement, iron, aluminum, and magnesium.
One major exception is phosphorus from phosphate rocks, used for agriculture. Though known and potential high-grade resources are very large, they are hardly inexhaustible. In the long run, as H. G. Wells pointed out, we will have to recycle bones as fertilizer. In addition, we may have to extract some of the 0.1 percent of phosphorus available in ordinary rock. Agriculture also requires trace elements, which are slowly depleted by modern agricultural methods. Among these are copper, zinc, and cobalt, whose availability from nonrenewable resources is limited. So in addition to recycling bones, we will have to return other agricultural and animal wastes to the soil.
This hopeful resource picture is clouded, in the near term, by the most important exception: energy-producing hydrocarbons. For use in plastics, there is plenty of carbon in limestone; in addition, the topmost kilometer of shale in the earth's crust contains 200 times as much hydrocarbons as in coal, oil, and gas. Most of this is too dilute, however, to be used as an energy resource. In considering energy-producing hydrocarbons, it is found they constitute one of the scarcest nonrenewable resources: twenty to twenty-five parts per million of the top kilometer of Earth's crust. Yet they constitute two-thirds of the world's demand for nonrenewables. Moreover, they serve for more than energy alone. Coal is used in producing iron (though it is replaceable by electrolytic hydrogen) and electricity - mostly fossil-fuel generated - is needed to produce aluminum. Energy is also needed to smelt other metals or to produce substitutes for materials in short supply. So the only important resource shortage is one of energy-producing hydrocarbons. Our social and economic structures are unlikely to be disrupted because we have to use lower-grade ores and resources, provided that we find an inexhaustible source of cheap energy to substitute for hydrocarbons.
There are three energy sources which could prove suitable: fusion, fast-breeder reactors, and solar energy. All three are being extensively studied and developed by a number of countries.
Fusion power has been a popular option for over 20 years. Its advocates have painted glowing pictures of limitless energy from the deuterium of the sea, free of pollution or of radioactivity, producing only the clean ash of helium. This is the dream but the reality is much different. To begin, fusion differs from other proposed energy sources because it alone has been identified as an energy option before it has shown the ability to produce energy. Current fusion experiments produce something like one watt of power for every million watts fed in to run them. Needless to say, such power production is extremely costly. Moreover, power from fusion presents formidable technical problems which are not likely to be solved in the near future.
A number of experimental breeder reactors have been built and have produced power. The breeder uses uranium-238, the common isotope which is 140 times as abundant as U-235, used in bombs. In the breeder, the U-238, which is not fissionable, absorbs a neutron and forms plutonium-239, which is, and which can be used to produce power. It also can be used to make nuclear bombs; it takes about 10 pounds of the stuff to make one. A large breeder reactor would have about 2000 pounds, at a value of $5000 per pound - three times higher than gold. By the year 2000, an energy economy based on the breeder would be producing 80 tons per year of plutonium-239 and at up to 500 shipments per week, the anticipated traffic, there would be ample opportunity for hijacking or diversion to the black market. If the breeder reactor is used as the means to bring the whole world up to American or European living standards, the world would need 15,000 reactors with old ones being retired and new ones being built at the rate of about 10 per week.
So fusion faces intractable technical problems; breeders face problems of safety. In addition, most proposed new energy sources have to meet economic goals. Currently, nuclear power plants and coal- or oil-fired generating plants are the most common means of generating electricity. All three represent predictable well-understood technologies; they generate power at costs in the rather narrow range of 1.8 to 3.0 cents per kilowatt-hour.
Cost estimates have been developed for several alternative energy sources. Geothermal power, which is already available in small quantities, looks to be in the range of 2.5 to 5.5 cents per kilowatt-hour. The fast breeder is in the range 3.5 to 5.5, while the best method of producing energy from fusion may be at 4 to 6. By far the most costly is ground-based solar power. The diffuse nature of solar energy, the need to track the sun in the sky, and the difficulty of building truly large single units, all combine to make the cost of a solar installation triple that of a breeder. The cost of electricity will be at least 7 and perhaps as much as 20 cents per kilowatt hour.
So the overall picture looks like this: To build a long-term livable world, we need population control in the underdeveloped countries, achievement of which will be aided by, and contribute to, a rising standard of living. Rising living standards demand continued supplies of resources, the availability of which is closely linked to the long-term supply of energy. And when we inquire into new energy sources, we find that they appear too costly, too unsafe, or too uncertain in their practicality to give genuine assurance that the world we seek is indeed achievable.
It is at this point that space colonization enters the picture.
The power satellites built in a space colony offer considerable promise as being the much-sought cheap, clean, and inexhaustible source of power. In space they can be built rapidly and at little cost to Earth. On the ground rectennas can be built at a cost of $1 or $2 billion for each 10-million kilowatt installation - a cost considerably lower than that of any ordinary power plant. The space program has often been criticized as expensive, a costly misuse of federal dollars. In fact, it is one of the least costly of the major United States programs, totaling about 1 percent of the federal budget. This low cost carries over into the use of an expanded space program to solve the need for energy. In the power industry, 100 billion dollars is only a small percentage of what will be needed to meet the growing demand for electricity in the remaining years of this century. In space colonization, 100 billion dollars buys a complete space colony with its supporting lunar base and industrial facilities, ready to turn out powersats as desired.
The low cost of powersat electricity - as low as 0.35 cent per kilowatt-hour - means that it could be used to produce cheap hydrogen, which can be piped and burned like natural gas, by electrolysis of seawater. The hydrogen could also be used to make gasoline, with carbon taken from atmospheric carbon dioxide or from limestone and other carbonate rocks.
There have been numerous studies of the details involved in using liquid or gaseous hydrogen as a replacement for the portable fuels in use today. It is generally agreed that hydrogen, or synthetic fuels made with hydrogen, can replace today's fuels for whatever applications wished. The main problem is the large increase in electric generating capacity needed to accommodate its production. For this the solution is simple: build more rectennas, build more powersats. The next century may see large numbers of rectennas serving as centers for major industrial parks. They will send some of their electricity by transmission lines to cities but much of the electricity will be used close at hand. There will be electrolyzer plants, producing hydrogen and also oxygen. There is no better way of treating municipal sewage or of removing pollution from rivers or lakes than with oxygen. Other plants will perform air separation, extracting atmospheric carbon dioxide and nitrogen. The former will be used together with some of the hydrogen to make gasolines, kerosenes, oils - a whole range of synthetic fuels and lubricants. Still other plants close to sources of energy and raw materials will turn out plastics and synthetic fabrics, fertilizers (using the nitrogen), pesticides, pharmaceuticals, and petrochemicals. Throughout the whole world: better things for better living through chemistry.
In principle there is a nice neat picture. Space colonies build powersats, which assure material prosperity and an abundant supply of resources, which promote the conditions for a stable population.
In reality, the picture is likely to be much more complex. The underdeveloped nations are not simply the Western nations minus electric toothbrushes. They have their own characteristic ways of living and thinking, which will change with time but now are no more relevant to such a future than the ecclesiastical feudalism of twelfth-century Europe is to the current advanced technological state of Western civilization. In many underdeveloped countries there is barely the foggiest notion of public trust. Corruption is a serious problem in the Third World but it need not be true indefinitely that the developing nations will be subject to the corrupt rule of cousins with black-market connections; these nations' desire for development can stimulate their ability to get things done.
Certainly, if they are to gain benefits from space colonization, they will demand arrangements which will assure them of their energy supply and not leave them subject to arbitrary price rises or to capricious interruptions. This should not be difficult to arrange. The rectenna, of course, will be located in the country it serves and under its control. Rectennas will be financed by the World Bank or by other international agencies rather than being subject to the uncertainties of foreign aid. The powersats themselves will be under the control of the colony, which will be responsible for their maintenance and upkeep and the colony's principal interest will be to grow, to build more powersats. The colony will wish to maintain friendly commercial relations with all nations. It will be very interested in proposals to lease the use of powersats or to sell their power at a fixed rate for a guaranteed term of years. After all, in their concern with growth and material development both the space colony and the countries of Africa or Asia will count as developing nations.
Beyond the material well-being, beyond the prerequisites for a decent world which will last a million years, lies the focus for human energy - the frontier.
Colonies in Space Chapter 15 Table of Contents
Copyright 1998-2016, National Space Society Updated Sun, Apr 24, 2011 at 01:17:14