Cecilia Herles. Encyclopedia of Environmental Ethics and Philosophy. Editor: J Baird Callicott & Robert Frodeman, Volume 2, Macmillan Reference USA, 2009.

In the year 1 C.E. there were approximately 200 million people on Earth—less than the population of the contemporary United States alone. It took nearly two thousand years for the global population to increase sixfold: In 1850 the world population was an estimated 1.26 billion. The next increase of nearly sixfold has taken only 150 years, less than one-tenth the time of the previous sixfold jump: As of 2008 the world human population was 6.5 billion. This rapidly increasing growth rate of population, with attendant steep increases in consumption of natural resources, threatens the well-being of Earth’s current and future inhabitants.

Environmental philosophers hold differing views on how humans affect the environment. Many questions and controversies have arisen in relation to the issue of population: Are resources disappearing? How do consumption patterns of a rising population change the human impact on the planet? Is there an optimal size of the human population? To what extent do humans have duties to other humans, other species, and future generations? Do ever-increasing rates of population growth augur more hunger, environmental degradation, and poverty? How do cultural and religious attitudes about gender, birth control, reproduction, and the institution of motherhood affect the size of families? How do gender, race, and class affect reproductive choices? How can population growth be restrained?

Malthus’s Gloomy Arithmetic

Until the early nineteenth century little thought was given to human population growth except as evidence of the success of the human enterprise on Earth. That view changed with the initial publication, in 1796, of An Essay on the Principle of Population by the English political economist Thomas Malthus (1766-1834). Malthus argued that population increases geometrically or exponentially (1, 2, 4, 8, 16, 32, and so on), whereas agricultural productivity can increase only arithmetically (1, 2, 3, 4, 5, 6, and so on), leading to an inevitable strain on resources. For example, a farm couple might own and cultivate a hectare of land and from its yield feed themselves and four children; if those four children each had four children of their own, then in the next generation the same hectare of land must feed sixteen people; then, at the same rate of fertility, there would be sixty-four mouths to feed in the following generation and then 256 in the one following that.

On Malthus’s calculation the ingenuity of the farm family might allow it to double the productivity of its hectare of land during the lifetime of the first generation, but any further doubling in productivity would be difficult. For example, suppose that the first-generation farm family produces 100 bushels of corn on its hectare of land, which would be adequate for six people. The next generation manages to produce 200 bushels on the same hectare, which must be divided not among twelve but among sixteen people. With great effort the subsequent generation might eke out an additional 100 bushels of corn from the same hectare for a total of 300, but that would have to be divided among sixty-four people. The share per person of food resources would therefore have gone, in the course of only three generations, from 6:100 to 16:200 to 64:300. At the same rate of fertility, in yet the next generation 256 people must share 400 bushels of corn if, by the most ingenious means, the original hectare can be made to produce as much—in which case the person to food ratio will be 256:400. At this point the hectare of land has reached its maximum possible productivity; hence the person-to-food ratio will shrink in the following generation to 1,024:400.

At this point several scenarios are imaginable: (1) starvation reduces family numbers to the “carrying capacity” of its hectare of land; (2) uncultivated wild land is appropriated and made to produce corn; (3) cultivated land belonging to another family is taken by force. Of course, an enlightened farm family might have foreseen the consequences of its own fertility and consciously limited its fertility rate to two—the replacement rate—by one means or another. But there are only two means of achieving a steady-state population: reduced fertility or increased mortality.

The “population problem,” first articulated by Malthus, is captured only iconographically in the parable of the farm family and their single hectare of land. In the real world the human population consumes and depends on resources other than corn—indeed, on resources other than food. The fertility rate of the actual global human population varies from decade to decade, having peaked in the 1980s; as of 2008 it was running only a few tenths of 1 percent above the replacement rate of approximately 2.1. As the fertility rate exceeds the replacement rate, the population grows by an annual percentage. Even a seemingly small rate of increase of only 1.3 percent would result in a doubling of the population in just fifty-three years. The fertility rate and the rate of population increase is not uniform throughout the world. In some regions fertility rates and rates of population increase are negative and in others positive; a region’s population growth or decline is also affected by emigration and immigration.

Julian Simon Vs. the Ehrlichs on Population Growth

Malthus’s concerns echo loudly in the debate between the late Julian Simon and Paul and Anne Ehrlich on natural resources and the size of the human population. According to Julian Simon (1981), natural resources are not limited; he argues that when one resource—such as petroleum—is depleted, its price rises, stimulating research and the development of substitutes such as bio-fuels. Simon thus encourages unbridled consumption of current natural resources, which generates wealth, which in turn may be invested in the development of new technologies to meet the increasing demands of a growing human population. He rejects research calling into question the patterns of consumption and trading practices of the wealthy nations of the global north. He thus contends that economic incentives working in free markets will result in less pollution and a better environment. In sum Simon believes resources will expand as a result of human ingenuity, and the environment will be shaped to fit human needs. He encourages the creation of artificial substitutes for things in nature and argues that our survival capacities will increase from generation to generation, despite (or because of) changes such as reduction in the number of species in the world.

Simon questions the reasoning behind negative views about population growth. For Simon human intelligence is the ultimate resource. He rejects policies that pressure people to have fewer children and instead argues that population growth offers positive benefits, despite short-term costs. According to Simon human talents and capabilities offer endless possibilities that can translate into innovative solutions to challenges such as pollution abatement and resources availability.

In Simon’s view population growth will not lead to more famine and desertification. The world eats better now than it ever has before, even in poor countries, according to Simon. He argues that when more food is needed, as both more land is brought under cultivation and advancing agricultural technology increases production per hectare, more food will be available. In addition, even as population increases, the number of farmers decreases while the amount of land per farmer is rising, and he views this as economically more efficient. In Simon’s view environmental degradation, habitat loss, and species loss are problems only if economic losses also occur.

In contrast to Simon’s view, the Ehrlichs (1998) contend that humans pose a dangerous threat to the environment. According to the Ehrlichs the growth of human population and consumption is responsible for the earth’s increasingly degraded environment and global insecurity. They believe that effective remediation is possible, but only if there is a halt and then a reversal of human population growth. They question the optimistic representations of the future of economic growth because such projections, in their view, do not include the significant environmental costs of pollution, environmental health risks, and faltering ecosystems. They question the ability of current market mechanisms to allocate resources properly and doubt that technological advances will be able to address the problems of depleted natural resources and environmental degradation. They do not believe that curbing the use of natural resources should be left to the market. Although some economic studies have focused almost exclusively on the negative economic effects of reducing the use of fossil fuels such as oil, the Ehrlichs argue that there are many possible benefits to reducing per capita energy consumption—especially improving the health of both human and nonhuman beings.

The Ehrlichs also distinguish between biological wealth, or natural capital, and economic wealth and capital. They argue that human consumption and pollution deplete biological wealth and threaten entire ecosystems; they note that there are no artificial substitutes for some natural resources such as air, land, and water, which are subject to unprecedented deterioration. Acid rain, water pollution, toxic waste, climate change, deforestation, and loss of biodiversity are a few of the many environmental problems that the Ehrlichs attribute to the unsustainable scale of human population and patterns of consumption. They point to anthropogenic climate change as a potential cause of biodiversity loss and argue that extinctions of species will in turn cause more serious disruptions of ecosystems such as forest destruction in Eastern Europe by acidic air pollution, the desiccation of the Aral Sea in the former Soviet Union, and desertification in the Sahel region of Africa.

The Ehrlichs believe that limiting the human population size and reducing consumption are preconditions of a sustainable future. In their view eating is one of humanity’s most ecologically destructive activities. They call attention to the problems associated with increasing the production of food, including use of synthetic agricultural fertilizers, irrigation, and chemical pesticides in green-revolution technology, which has been touted as the key to boosting food production to keep pace with population growth. They cite substitutions of synthetic pesticides for natural pest control, inorganic fertilizers for natural ones, and chlorination for natural water purification as examples of unsatisfactory attempts to create artificial alternatives to ecosystem services. They argue

that humanity’s struggle both to feed the poor and to overfeed the rich is one of the principal causes of environmental degradation. They also note that human population growth and proportionately increasing pressures on food production result in the urban sprawl that devours agricultural land, which in turn spurs the conversion of forests and other natural plant communities into cropland for food production. Thus the task of saving the remaining forests is made harder because of the demands of a growing human population and its need for more food and wood products.

“Tragedy of the Commons,” Famine, and Future Generations

Garrett Hardin (1974) critically examines the once-popular metaphor of the earth as a spaceship that we all live on and must share equally. Hardin prefers the metaphor of a lifeboat. Each wealthy nation can be conceived of as a lifeboat, full of rich people with low fertility rates, whereas the rapidly reproducing people of poor countries are swimming in water, begging for admission to a lifeboat. He argues that we need to recognize the limited carrying capacity of any lifeboat. Sharing in accordance with the spaceship ethic will soon swamp lifeboats and everyone will drown.

According to Hardin spaceship ethics is problematic because it leads to the “tragedy of the commons.” Using the example of pastureland, Hardin argues that an owner adequately cares for his privately owned pasture because overshooting its carrying capacity will lead to a deterioration of the health of his herd and, therefore, economic losses. A farmer would recognize and restrain himself within the carrying capacity of his privately owned pasture. If, however, a pasture becomes a commons open to all, it is less likely, Hardin argues, that each individual will refrain from overshooting the carrying capacity. If one person increases his herd by one, the health of all the animals grazing on the commons will suffer, including his own; the value of adding an additional animal will benefit him alone, whereas the cost of doing so will be shared by all.

In Hardin’s view common ruin is inevitable if there is no “mutual coercion mutually agreed upon”— regulations, in a word—and he points to air and water as examples of resources that are polluted because they are treated as an unregulated commons. The economic benefits of a polluting industry flow to its owners, whereas the costs of pollution are borne by all. Hardin argues that a free good is likely to become an overused or wrongly used good. He calls into question relief for nations in need by a world food bank, which he regards as a commons in disguise that will eventually bring ruin upon all who share in the commons, according to Hardin. Despite its good intentions, he believes such a system of sharing would encourage the population-growth differential between rich and poor countries. Because poor countries have faster rates of population growth than wealthy countries, this trend, he argues, would only increase with a global system of sharing. He contends that with increasing population growth some nations threaten to exceed—or have already exceeded—their carrying capacity. Hardin argues that when assistance is offered from abroad in order to save poor people plagued by famine, this well-intentioned humanitarianism backfires by diminishing the quality of life for those who remain and for future generations. He calls for those in the lifeboat to consider their commitment to future generations as well as to themselves.

William Aiken (1980) calls into question Hardin’s judgment that it is a nation that has a carrying capacity. Aiken argues that the biological notion of carrying capacity is not applicable to the concept of a nation. Nor, in his view, is the natural environment, artificially carved up into nations, a boat that will necessarily “sink” when extra people are added. Aiken suggests that the concept of carrying capacity is ambiguous. Because technology leads to continual increases in the human carrying capacity of the environment, there is no way to determine that capacity precisely. Surely, he argues, there is an absolute limit to the number of people Earth can accommodate, but what that limit is or whether we are beyond it, closely approaching it, or still far from it is not known. Aiken also notes that Hardin focuses on mortality and ignores alternative fertility-focused methods of reducing population such as birth control.

Consumption Patterns and Population

Humans do not all consume the same amount of resources and generate the same amount of waste. Resource consumption and waste generation vary significantly between developed and developing nations. Only one-fifth of the planet’s population lives in industrialized north, but it consumes more than two-thirds of the world’s resources. The rest of the world shares what remains. The United States has less than 5 percent of the world’s population and uses approximately 25 percent of the world’s resources. In Women and the Environment (1993) Annabel Rodda notes, for example, that in the industrialized nations the average person is likely to consume more than 200 pounds of paper and 900 pounds of steel per year, compared to approximately 17 and 94 pounds, respectively, consumed by the average Third World resident. The industrialized nations use significantly more energy than the rest of the world; Julie Sze (1997) notes that the average citizen in the United States uses energy at the rate of 3 Japanese, 6 Mexicans, 12 Chinese, 33 Indians, 147 Bangladeshis, or 422 Ethiopians. The environmental footprint of First World residents is much deeper than that of the typical citizen of the Third World.

Total, Urban and Rural Populations by Major Area, Selected Periods, 1950-2050
Major Area	Population (millions)					Average Annual Rate of Change (percentage)
	1950	1975	2007	2025	2050	1950-1975	1975-2007	2007-2025	2025-2050
SOURCE: United Nations Department of Economie and Social Affairs/Population Division. World Urbanization Prospects: The 2007 Revision, February 2008.
Total population
Africa	224	416	965	1394	1998	2.48	2.63	2.04	1.44
Asia	1411	2394	4030	4779	5266	2.12	1.63	0.95	0.39
Europe	548	676	731	715	664	0.84	0.24	−0.12	−0.30
Latin America and the Caribbean	168	325	572	688	769	2.65	1.77	1.02	0.45
Northern America	172	243	339	393	445	1.40	1.03	0.82	0.50
Oceania	13	21	34	41	49	2.03	1.49	1.05	0.65
Urban population
Africa	33	107	373	658	1234	4.76	3.90	3.15	2.52
Asia	237	574	1645	2440	3486	3.54	3.29	2.19	1.43
Europe	281	444	528	545	557	1.84	0.54	0.18	0.08
Latin America and the Caribbean	69	198	448	575	683	4.21	2.55	1.38	0.69
Northern America	110	180	275	337	401	1.98	1.33	1.11	0.70
Oceania	8	15	24	30	37	2.60	1.44	1.17	0.89
Rural population
Africa	192	309	592	736	764	1.92	2.03	1.21	0.15
Asia	1174	1820	2384	2339	1780	1.75	0.84	−0.11	−1.09
Europe	267	232	204	170	107	−0.57	−0.41	−1.00	−1.84
Latin America and the Caribbean	98	126	124	113	87	1.01	−0.06	−0.50	−1.08
Northern America	62	64	63	56	44	0.11	−0.02	−0.65	−1.00
Oceania	5	6	10	12	11	0.88	1.60	0.78	−0.04

Waste

Residents of the industrialized nations generate more waste than people living in the rest of the world. For example, the average person in the United States produces almost 2,000 pounds of solid waste per year. Americans and Europeans are consumers of high-tech consumer electronics such as computers, cell phones, and televisions, which now constitutes the fastest-growing part of municipal waste in the United States and Europe. According to a 2001 Environmental Protection Agency report, this discarded electronics waste generated approximately 70 percent of the heavy metals and 40 percent of the lead now found in landfills in the United States.

Citizens of wealthy nations are largely responsible for toxic dumping, the destruction of biodiversity, and soil and water depletion. Often race is the main factor in the location of hazardous-waste disposal sites in the United States. This inequitable burden also occurs on a global scale. Developed countries produce large amounts of waste that are often transported to poor nations and can cause environmental degradation. Despite international regulations, approximately 80 percent of the electronic waste generated in a year in the United States is being exported to poorer countries such as China, Pakistan, and India, and to countries in West Africa. Large

containers of computer parts are shipped to less-wealthy nations and workers in these countries crack open and melt computer parts over open flames to retrieve metals. The toxic chemicals, vapors, and particles released in this process include lead, polyvinyl chloride (PVC), and poly-cyclic aromatic hydrocarbons (PAHs), all of which are persistent toxics. According to Elizabeth Grossman (2006), samples taken in Guiyu, China, in 2005 found levels of copper, lead, tin, and cadmium 400 to 600 times higher than what would be considered normal and safe. These samples also found polychlorinated biphenils (PCBs), PAHs, brominated flame retardants, nonphenols, phthalates, and triphenyl phosphates. As a result of this exported e-waste, the air and water in this region have been severely polluted.

Poverty Economics and Population

Affluent, developed countries have lower fertility rates and thus lower rates of population growth than poor, developing counties. Jack Hollander (2003) believes that poverty is the root of population growth—indeed, of all environmental problems; he asserts that only a free and affluent society can achieve zero population growth and environmental protection. Hollander therefore argues, in contrast to the Ehrlichs, that population growth is not a serious long-term global problem. He points out that the Ehrlichs’ predictions of massive famines have not been borne out. Instead of focusing directly on limiting population growth—by, for example, withholding food aid or promoting contraception—he recommends economic development, technological progress, and unregulated capitalism to eliminate poverty and thus to slow and ultimately halt population growth.

Hollander also believes that eliminating poverty will improve environmental quality. He thinks that for the 80 percent of the world’s people who are not affluent, life’s basic necessities take on a higher priority than environmental quality. He maintains that when people have economic and educational opportunities, the human population will stabilize and efficient agriculture will reduce or eliminate hunger and the demand for more land for food production. He contends that economically secure people demand environmental protection.

The Ehrlichs insist, in opposition to Hollander, that a rich person contributes much more to the damaging of Earth’s life-support systems than does one living in poverty. Restricting the size of human population, not increasing affluence, should be the first priority for healing the planet, in their view. The Ehrlichs call attention to the energy trap. More energy is required to give all human beings an affluent lifestyle; although developing and deploying these energy sources would be very difficult and costly; using that much energy would create an even larger threat to ecosystems. The Ehrlichs therefore emphasize two key imperatives: reducing consumption and waste generation by the rich and limiting the population growth of all humans, rich or poor.

Gender, Race, Class, and Population

Gender, race, and class have been prominent issues in debates about human population. Some argue that gender, race, and class are often not adequately addressed in Ehrlich-style population-restraint perspectives. Recommendations of a reduction of population growth can be seen as racist and classist in condemning the rapid growth that occurs mostly in areas outside of the ambit of the developed countries. Such critics argue that the Ehrlichs’ arguments fail to address the reasons for rapid growth in the third world.

Vandana Shiva (1989) argues that there is a link between the destruction of nature and the oppression of women. She argues that agriculture has shifted into two sectors: the cash-mediated masculine sector and the subsistence-oriented feminine sector. As a result the cash economy draws men away from the land, increases women’s workload in producing subsistence, and disrupts ecosystems because of the green revolution’s focus on growing irrigation-dependent cash crops through the use of synthetic chemicals. Shiva asserts that, as more land is diverted to cash crops and degraded by green-revolution technologies, women have less access to land and other resources but increased burdens in food production for family subsistence. As a result of the environmental degradation caused by industrial agriculture, Shiva notes that women must walk longer distances for water, fodder, and fuel.

Val Plumwood (1991) argues that numerous studies have shown that, in the Third World, ecologically insensitive, high-technology agriculture and forestry strengthen the control of the elites over natural resources and aggravate social inequalities, including men’s control over women. Ecofeminists such as Shiva and Plumwood argue that the key to stanching population growth in developing countries is not withholding food aid and promoting contraception or increasing affluence and consumption: They believe that the solution lies in ensuring women’s economic and reproductive autonomy. When women are empowered with education, economic means, and reproductive choices, they are more likely to be able to choose to have fewer children because their status may not be as dependent on bearing many children. In addition, they may not feel the need to increase the economic workforce of children as a means of making ends meet. Fewer births may benefit these women in several ways including their health and their efficiency in managing natural resources.

The ecological feminist Chris Cuomo stresses the importance of considering categories such as gender, race, class, and sexuality in an analysis of the complex issues involved in population growth (1994). She points out that some approaches to population control lack a critical analysis of the many social factors underlying gender oppression. She notes that these social factors—including the institution of motherhood and attitudes about sexuality and women’s bodies—which contribute to the growth of human population, are ignored in many biology-based theories about “carrying capacity” and “standard of living.” She calls attention to the inadequacy of viewing humans as a homogenous species and thus failing to recognize the impact of gender, race, and class on population growth. Cuomo asks, “Why do women bear many children, even in areas or communities where high population density impacts on individual lives very directly, through overcrowding, shortages of food and other necessities, poor health and hygiene, and the obvious destruction of local land and species?” (1994, p. 95).

Cuomo argues that sexism, the institution of motherhood, racism, classism, cultural factors, sexuality, and health issues fuel population growth. The ecofeminist approach acknowledges and examines in detail the need for the disempowerment of women in various ways: in terms of control over their own bodies, their roles in culture, and their sexuality, and their identities as they relate to the environment in which they live. According to this view, women’s systematic oppression in patriarchal societies directly relates to the degradation of the natural environment.

Ecofeminist writers have linked women’s oppression and the feminization of poverty to human population growth. Ronnie Zoe Hawkins (1992) notes that, although women often seek to limit family sizes, they are sometimes denied access to the means for doing so. Cultural beliefs and values in a patriarchal society often pressure women into bearing many children, even at the expense of their own health. Forms of birth control and abortion may be prohibited by religious or cultural views or both. In addition, women may be alienated from their own bodily functions and processes.

The roots of population growth are thus seen to lie in the poverty and patriarchy that form institutionalized barriers to women’s freedom of reproductive choice. For example, many Third World cultures discourage the open discussion of birth control, and contraceptive devices are not readily accessible. In many cultures male babies are seen as more valuable than females; the overwhelming majority of abortions in countries such as China and India are performed to prevent the birth of females, resulting in de facto gendercide. Although this practice may limit population growth because there will be fewer mothers to bear children, feminist critics have pointed with alarm to its grave ethical implications.

Of all the roles traditionally assigned to women, motherhood is the one that is most common across cultures. The ideal of a good mother as a woman constantly bound to her children, physically and emotionally, willing to sacrifice herself and put the children’s welfare before anyone else’s, including her own, is a demanding ideal, but its perceived nobility offers insight into the reasons that some women continue to reproduce in circumstances where high population lowers their standard of living. Another explanation turns on the economic value of children as part of a family workforce in poor agrarian communities. Third World women often participate more than men in the food system. Women in Africa produce more than 70 percent of Africa’s food. Andy Smith (1997) argues that it is often in the economic interest of Third World women to have more children in order to raise more export crops and earn more money.

Smith argues that population-control measures are needed most urgently among the prosperous citizens of the United States because of their rapid rate of consumption of resources. Sze (1997) notes that Third World immigrants and refugees of color with high fertility rates threaten to outbreed the low-fertility white populations of industrialized countries. Sze argues that white fears of “Third World-ification” by Latinos and Asians assume that the world’s people of color are to blame for environmental degradation caused by overpopulation.

Some further argue that methods of population control have been threats to the reproductive health among women of color. For example, Smith and Lori Gruen call attention to the history of forced sterilization of women of color and the history of U.S. contraceptive companies marketing dangerous drugs such as Depo-Provera to other countries.

Conclusion

While gender, race, and class issues are crucial for consideration in analyses of human population size and growth, it is important that such studies do not use women, particularly women of color, as scapegoats. Reproductive choice is a human rights issue as well as an environmental issue. Policies geared toward the empowerment of all women in their reproductive choices are necessary in order to move toward a more sustainable human population and a healthy planet for all.