Overpopulation and the Catholic Church: Can't We Become Part of the Solution?

By Daryl Domning, Anne Cole, John Czajka,
Fred Leone, Hubert Ngueha, and Nestor Ymeli


There is now worldwide scientific consensus that human activity is bringing about global climate change. The exact nature, extent, and rapidity of the coming changes are uncertain, but every batch of new data seems to show that the changes are coming faster than the latest computer models projected. The worst-case scenarios extend to the effective collapse of technological “civilization as we know it” within the 21st century.

This will strike some as laughably over the top; but it may be all too near at hand. Lester Brown (Scientific American, May 2009) sketches one realistic scenario: water shortages and loss of topsoil joining with global warming to create worldwide food shortages and a cascade of failed states that brings down the economic and geopolitical order. Global warming in particular has seized the world’s attention with the realization that we humans can and do change things up to the scale of the Earth’s very climate.

This public consensus now needs to take one further step: to acknowledging that the amount of harmful human activity results from not only our consumption patterns but the size of the human population itself – because even the poorest humans have an ecological impact.

The now-threatened breakdown of our civilization could be compared with the fall of the Roman Empire, except that it would be quicker, worldwide, and would affect the very life-support systems of humanity for millennia to come. As documented in Jared Diamond’s 2005 book Collapse, several civilizations have gone this way before, mostly due to local overpopulation. We dare not risk trashing, this time globally, the only home we have: there is no Planet B.


The Role of the Church

Following the fall of Rome, the Christian church played a crucial role in history by helping to fill the vacuum of civil authority in the West. Today the Catholic Church (as arguably the oldest, largest, most prestigious, and most influential institution on Earth) needs once again to rise to the occasion – by moral leadership in protecting the Earth’s environment. Fortunately, this has already begun, as seen in statements such as The Ecological Crisis: A Common Responsibility (John Paul II, 1990), Renewing the Earth (U.S. Catholic Conference, 1991), And God Saw It Was Good: Catholic Theology and the Environment (U.S. Conference of Catholic Bishops, 1996), and the 2009 Catholic Climate Covenant. Pope Benedict XVI is already called “the Green Pope” for his repeated exhortations on this subject.

Nonetheless, the church’s environmental agenda still lacks a crucial component: acknowledgment of human overpopulation as the fundamental cause of our crisis. Our bishops’ badly needed efforts for the environment directly conflict with their adherence to Pope Paul VI’s 1968 teaching in his encyclical Humanae Vitae, i.e., rejection of artificial contraception. Though benevolent in their intent, this document and others echoing it have determined for decades the Holy See’s lonely opposition to most international programs of family planning; and this policy still wields massive influence, even beyond the church’s denominational boundaries, by lending legitimacy to conservative religionists worldwide who support “pro-natalist” policies. The hierarchy’s continued insistence on this teaching, in the face of ecological, demographic, and psychological evidence, is the Galileo case of the 20th (and now 21st) century.


The Problem: Population

The global impact of human population growth is nothing new; in fact it has been wreaking havoc on the planet for thousands of years. As argued by University of California paleontologist Anthony Barnosky (Proceedings of the National Academy of Sciences USA 105, suppl. 1, Aug. 12, 2008), the global mass extinction of many large land animals some 10,000 years ago (due to hunting and habitat alterations by humans, combined with natural climate changes including global warming) was followed by humans’ “coopting the energy previously shared among other species with big bodies.” By its sheer biomass and aggregate consumption of resources, humankind literally forced numerous species out of existence and then replaced their biomass with its own growing numbers, precluding recovery of other depleted species. Later, we increased the global energy budget by mining fossil energy, allowing our biomass and that of our domestic livestock (but not other species) to increase by orders of magnitude above the original baseline. If the dwindling fossil fuels are not replaced by alternative energy sources, says Barnosky, another biomass crash, “this one depleting human biomass”, could occur “in as little as a few human generations.” The biosphere (to say nothing of civilization) could not recover from such a crash for thousands of years – far longer than the crash itself took.

For both practical and moral reasons, therefore, we must not only halt but reverse the growth of the human population and its consumption of nonrenewable resources, before this crash (which has already begun, in the form of accelerating loss of biodiversity) proceeds to its conclusion. We need a remedy that is likewise practical as well as moral: not only a responsible population policy, but (right alongside it) development to provide social and economic security for all people, so they no longer need numerous children as retirement insurance. Equally, we need new technology to reduce our ecological footprint. But replacing fossil fuels (for example) with renewable energy would address only one factor limiting future survivability—and almost certainly not soon enough to prevent widespread hardship. We cannot look to technology and development alone to solve our problems without simultaneously addressing overpopulation.

The hierarchy’s customary reply to this critique is that the ecological crisis is due, not to global overpopulation, but simply to overconsumption in the developed world, and that the solution lies in development of poor nations, not birth control. Now, no one disputes the moral imperatives to rein in overconsumption by the rich while raising the standard of living of the world’s poor. But the bishops overlook two things.

First, even sharing everything equally will do little good if each share is too small (see Objection #3, below). Second, development necessarily means increasing the poor’s consumption of resources – which will only worsen the overall ecological problem. Though most obvious in the increased greenhouse emissions caused by rapid development in China and India, this is true of all development. Not only the rich but even “masses of people … living in conditions of misery at the very lowest level of subsistence” (John Paul II, The Ecological Crisis, no. 8) can degrade their environment catastrophically, for example by overfishing, deforestation, or soil erosion.

This is the critical dilemma for Christians and all people of good will, and the critical mistake that we are making as a church: to imagine that we can simultaneously end poverty and preserve the life-support systems of an already-overpopulated planet, without reducing the size of the population. What might be possible in a world with a much smaller and sustainable population is not possible now that our population is already unsustainably large: it leaves us no more room, or time, to maneuver.


A Responsible Solution

We must face the fact that we live in a world of limits: limited resources, limited carrying capacity, and limited tolerance for the multiplication and other doings of human beings. The only way to alleviate world poverty and achieve a minimum overall standard of living consistent with human dignity, while simultaneously bringing under control global environmental damage, is to significantly reduce the world’s population to bring it in line with what the planet can indefinitely sustain. This capacity cannot be precisely calculated, but it may be no greater than the world’s population was in 1950: 2.5 billion, as opposed to the 7 billion we are now rapidly approaching (Lindsey Grant, 2008, The Edge of the Abyss). Others, less optimistic, estimate a maximum sustainable population of only 1.5-2 billion, as it was around 1900 (e.g., G. Daily et al., 1994, Optimum Human Population Size; D. Erickson, 2000, Sustainable Population Levels Using Footprint Data. See also Towards Sustainable and Optimum Populations and The Most Overpopulated Nation ). But even if these estimates are wide of the mark, they represent serious attempts to come to grips with the problem, and their point is that any sustainable population would have to be much lower than today’s. We must turn the upward-bound global growth curve downward as soon as possible.

There are only two ways: increasing the death rate, or decreasing the birth rate. Since the former (whether by war, genocide, abortion, or other deliberate means) is unacceptable, shrinking the human race by two-thirds or more will require reduction of global birth rate to well below replacement level (an average of 2.1 children per woman), by massive use of (and incentives for) contraception. That such a change, even within this century, is possible and compatible with democracy is shown by Japan, which is on track for a population decline of 25% by 2050 (Population Reference Bureau, 2009).

People instinctively reduce their fertility when resources are scarce – as shown by the reported rise in contraception and drop in pregnancies in the USA during the current recession (Gallup poll, May 2009). If this natural prudence of individuals and families is not applied to the whole world’s needs, nature will, inevitably, step in and increase our death rate for us, by famine and pestilence. These will be in addition to the wars, et cetera, that we hoped to avoid, but which will become unavoidable in more cases as crowding increases and resources diminish – as already seen in places like Rwanda and Darfur. As noted in a 1998 analysis of the 1994 Rwandan genocide quoted by Diamond, “[i]t is not rare, even today, to hear Rwandans argue that a war is necessary to wipe out an excess of population and to bring numbers into line with the available land resources.” While such horrors always have numerous proximate causes (social, political, etc.), we must not remain blind to the frequently underlying role, whether conscious or unconscious, of population pressure.

Without prudent restraint, the unconscionable result, dictated by the laws of ecology, will be horrific human suffering and a reduction of Earth’s carrying capacity for humans even below what it would have been prior to the population crash. This is what happens with every natural population that seriously outgrows its resources: it crashes catastrophically and takes its habitat down with it.

Ironically, our hitherto pro-natalist norms have betrayed us by too-close conformity to another of nature’s laws: the Darwinian law that dictates as much self-replication as an individual or species can manage. The Darwinian boom-and-bust we are now trapped in is not the way to the Reign of God. It more befits human dignity to restrain this self-centered urge to procreate, and instead to choose living within our means, by responsible stewardship and parenthood.


How the Teaching Can Change

There is ample ground for this choice in our scriptures and tradition. Stewardship of God’s creation is a basic biblical theme about which much has already been written (e.g., Denis Edwards, 2006, Ecology at the Heart of Faith; Nancy G. Wright and Donald Kill, 1993, Ecological Healing). Another theme is the beneficent creativity of the Divine Mind in devising responses to new situations that are often the result of human vice and error. For example, even while punishing Adam and Eve, God provides protective clothing, a new invention previously not needed (Genesis 3:21); the fratricidal Cain receives a special protective mark (Genesis 4:15); Noah’s ark is uniquely designed by God, who for the first time is visibly engaged in naval architecture (Genesis 6:11-22). Moreover, not only does God cause a swath of dry land to bisect the sea (Exodus 14:21-22), but also, in a reverse procedure, God waters the desert to enable the Israelites to return from their punitive exile in Babylon (Isaiah 43:16-21). In regard to the latter, God even announces through the prophet, “See, I am doing something new!” (Isaiah 43:19) What remains constant throughout salvation history is God’s will to preserve human life; what changes from age to age is God’s modus operandi. This is a Creator with an unlimited and versatile imagination. Would such an infinitely creative God reject out-of-hand an effective means of preserving the creation, simply because it is human-made (“artificial”)?

Even St. Augustine, whose work The Good of Marriage is sometimes cited against contraception, points out this versatile divine creativity as revealed in Holy Scripture. Whereas God once permitted the Old Testament patriarchs to engage in polygamy and concubinage, monogamy is now the norm. The reason, according to Augustine, is that God once wished the chosen people to multiply, but now, in the Christian era, there is no need for a burgeoning population. Augustine says, “There is not the need for procreation which there was then, when it was permissible for husbands who could have children to take other women for the sake of a more copious posterity, which certainly is not lawful now,” and he attributes this drastic change in marital mores to “the mysterious difference of times” (The Good of Marriage 15, trans. Charles T. Wilcox, 1955, Fathers of the Church 27).

Although Augustine names “offspring” (proles) as one of the three “goods of marriage”—that is, the three features of marriage that render it a fully Christian way of life, to be respected rather than rejected—the anti-Manichaean context of this treatise is crucial to understanding it. Part of Augustine’s purpose in writing it was to refute the disparagement of marriage by Manichaean believers who spurned the physical creation and the Old Testament revelation of a God who acts through material means, and thus regarded the conception of each new corporeal being as an addition to the dark force of evil matter. Augustine’s emphasis on procreation in marriage is thus an affirmation of the goodness of God’s physical creation over against Manichaeism—and environmentalists today heartily agree. Moreover, Augustine’s opinion that the only positive aspect of marital intercourse is the procreative one has been rendered obsolete, since the Church has subsequently recognized the unitive aspect also.

In her book Guests of God: Stewards of Divine Creation, which sparked our reflections here, the late theologian Monika Hellwig ponders the many ways in which God shows hospitality to us, and how we are called to respond but fall short. Her wide-ranging critique of human behavior is meant also for our church community, which has not always been a well-behaved guest in God’s world, or modeled God’s care for its creatures – including the needs of future generations.

Our bishops must now recognize that preserving the long-term fruitfulness of the Earth and its ability to support humankind is a valid and “grave” motive for limiting births (cf. Gaudium et Spes, no. 50; Humanae Vitae, nos. 10, 16), trumping the narrowly individual aspect of the issue that is traditionally the only moral lens they have looked through. Their persistence in this narrow outlook, as blind to global environmental costs as Galileo’s opponents were to the mountains on the Moon, has become a form of structural sin. As Benedict XVI has said (July 25, 2007), “obedience to the voice of the Earth is more important for our future happiness ... than the desires of the moment. Our Earth is talking to us and we must listen to it and decipher its message if we want to survive”. He notes further “our grave duty to hand the earth on to future generations in such a condition that they too can worthily inhabit it and continue to cultivate it” (Caritas in Veritate, no. 50).


Envisioning a Sustainable Future

Beyond merely tolerating the limitation of births for this gravest of reasons, however, the Catholic hierarchy has a moral duty in the present crisis to forcefully promote such limitation, including by responsible use of contraception, at the same time as it promotes development. The preferable alternative to the government-imposed mandatory birth control condemned in Caritas in Veritate (no. 44) is not our present feckless course, but voluntary birth control to implement the “responsible procreation” urged by Benedict XVI in the same paragraph.

Indeed, one can find the principle of responsible stewardship well stated even in the U.S. bishops’ defense of the traditional teaching and reliance on “natural family planning” (NFP): “The spouses are to exercise the virtue of prudence in a considered assessment of the well-being of the whole family. Reason and will are not to be abandoned in favor of a passive submission to physiological processes. Husband and wife are called to stewardship of all their gifts, especially fertility …” (Shivanandan, "When Can We Use NFP?"). Such words can plainly lend themselves to development of doctrine in the direction we urge, as soon as the bishops recognize what the well-being of the whole human family now requires.

NFP alone is inadequate to the need, as it does not work for everyone. The heroic efforts of devout Catholic couples who have sought to limit family size with NFP deserve admiration; but the training and commitment that NFP requires makes it analogous to a monastic charism that is not to be expected even of most Catholics, let alone the other billions who must also grapple with overpopulation.

Thus there is no escaping the need to reverse Rome’s ban on “artificial” birth control – a ban which in any case is theologically a dead letter, having been widely rejected by the sensus fidelium from the day Humanae Vitae was promulgated. It cannot justifiably be imposed on anyone’s conscience: living within our means cannot be immoral. By his numerous confessions of the church’s past errors, John Paul II enhanced rather than undermined the church’s credibility. The same will be true in this case. In the face of resentment that past church teachings worsened our environmental woes by delaying the cure, it will help heal the church’s reputation and credibility to have come around late rather than later. It is good that the church “thinks in centuries”; too few institutions nowadays take the long view. But it’s time that our church started to think in the twenty-first century instead of the nineteenth.

However moral it may be, is the idea of inducing world population to decline by two-thirds a “practical” one? We submit that it is more practical than imagining we could live with the alternative – which could be the standard of living of Ethiopia today, or worse (see Objection #3, below). It is a stunning prospect, to be sure. But if we think we can continue as we are, let alone raise up the poor, without bringing world population into line with our resources, then we are as foolish as the man who began to raise a tower without calculating the cost (Luke 14:28-30).

In today’s ecological crisis, the church is called on as never before to put its leadership on the line in service to this world. Undeniably, the population drawdown we advocate, in both the developed and the developing worlds, will require many sacrifices. The church can set an example by sacrificing its own long-held views that have proven obsolete. Jesus, who put the concrete needs of people ahead of “traditions of the elders” (Mark 7:1-13), expects nothing less of us.

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Answers to Objections:

1) Shouldn’t we trust God to provide for our growing population? Reply: Indeed, we have heard it seriously argued that Jesus multiplied loaves and fishes for the multitude, and therefore we should await in faith and trust (and complacency) a divine solution to our dilemma. Yet history shows that God does not intervene even to save us from our worst follies of war and genocide. God takes our responsibility of stewardship very seriously (Matthew 25:14-30), and will not look kindly on our expecting him to pull our chestnuts out of the fire. “Scripture has it, ‘You shall not put the Lord your God to the test.’” (Matthew 4:7)

2) Given the general rejection of Humanae Vitae by Catholics, not to mention others, isn’t this whole issue of the church’s teaching moot? Reply: Many Catholics still feel bound by this teaching; it still profoundly influences government policies in some nations, e.g., the Philippines (Blaine Harden, The Washington Post, April 21, 2008); and most of all, the world does not need the bishops’ marginalization, or their grudging acquiescence to contraception, but their forceful, committed support of population reduction.

3) Isn’t the real problem not overpopulation but overconsumption? Reply: Environmental impact is proportional to the product of population and per-capita consumption; both are part of the equation. Even if each person consumed the absolute minimum needed for life, unlimited population growth would soon exceed the carrying capacity of a finite planet. The Earth could probably sustain even a wasteful American standard of living for everyone, if there were only half a billion humans. But Americans, with less than 5% of the world’s population, are estimated to use 20% or more of the world’s energy reserves and other critical resources. For everyone to consume like us, we would need the resources of three or four additional Earths. Thus, the United States is arguably the most dangerously overpopulated nation, and the most in need of population reduction. Conversely, for everyone to have an equal share of the actually-available resources, we Americans would have to make do with one-quarter or less of what we now enjoy. Are we likely to accept that? And as population continues to grow on a fixed resource base, that “equal share” per person becomes less and less compatible with human dignity. “The UN currently projects the world's population at 2050 to be between nine and ten billion. In order for that population to be sustainable, … the highest sustainable average living standard would be approximately … the living standard … of Ethiopia today. This is a difficult and harsh standard of living that all nations have struggled for centuries to move away from —approximately one-third the current world average standard of living” (Erickson, op. cit.). This is our choice: will we humans return to one-third of our present population (of almost 7 billion), or to one-third of our standard of living?

4) Won’t a rapid decline in birthrates create “graying societies” like Japan’s, with workforces inadequate to support massive numbers of retirees? Reply: Fewer young dependents help compensate for more old dependents. The socioeconomic problems of a shrinking population are mild and transient compared with those of an exploding population, and are now, in any case, our only route to the ideal: a stable population in balance with its resources. Besides, for the foreseeable future there will be more than enough would-be immigrants to meet the labor needs of any nation willing to admit them.

5) Won’t church approval of contraception encourage promiscuity? Reply: This amounts to arguing that disease and unwanted pregnancy deter promiscuity; therefore the church should do nothing to diminish these risks of disease and pregnancy. But this is morally untenable. In any case, the hierarchy’s present disapproval of contraception could hardly be more widely ignored by individuals with the means to do so, even where it still influences governments (see Objection #2 above) – mainly because it is based on arguments that are unpersuasive to most people. The increase in overall credibility of church teachings to be gained by overhaul of the teaching on contraception is more likely to strengthen than to undermine those moral precepts that are seen by people of good will as logically defensible, such as condemnation of promiscuity.

6) Won’t concerted efforts to cut the global birthrate lead to abuses like the formerly forced sterilizations in India and forced abortions in China? Reply: Rather than using such horror stories to discredit the entire idea of a responsible population policy, we should say “There, but for the grace of God, go we!” If overcrowding could drive those societies (which traditionally value children and families as much as any) to such desperate policies, it can do the same to us. The pressures leading to such abuses increase with every day we fail to effectively implement more humane measures.

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The authors are members of a Christian Life Community in Silver Spring, Maryland:

Daryl Domning is a paleontologist and Professor of Anatomy at Howard University, Washington, D.C.

Anne Cole (pseudonym) teaches church history at a graduate school of theology in Maryland.

John Czajka is a demographer and Senior Fellow at Mathematica Policy Research, Washington, D.C.

Fred Leone is a retired Executive Director of the American Statistical Association (ASA), and Fellow of the ASA and of the American Society for Quality Control.

Hubert Ngueha is a student in the Washington, D.C. area.

Nestor Ymeli is a computer network engineer in Falls Church, Virginia.