“The battle to feed all of humanity is over. In the 1970s and 1980s hundreds of millions of people will starve to death… It cannot be overemphasised, however, that no changes in behavior or technology can save us unless we can achieve control over the size of the human population.” Despite seeming to come from a dystopian novel, these ideas belong to biologist Paul Ehrlich and were popularised in his highly successful 1968 book The Population Bomb.
Ehrlich’s environmental campaign was in its early stages when he stated that “nobody has ever come up with a reason to have more than 140 million people alive at the same time in the United States”. In order to prevent a catastrophe that the biologist believed would begin to show signs in the early 1980s, Ehrlich called for strict measures such as compulsory sterilisation and a tax on baby carriages.
More than half a century after the publication of his controversial book, Ehrlich, who is the Bing Professor Emeritus of Population Studies of the Department of Biology of Stanford University, believes that, aside from certain details or a miscalculation of the timing of the predicted events, the book remains accurate and relevant. Insisting that “perpetual growth is the creed of the cancer cell” the biologist notes that we should anticipate the almost certain collapse of our civilisation in just a few decades as a result of population growth and excessive consumption of natural resources. Ehrlich argues that solutions exist, but the extreme ones will be rejected and the mild ones will not act quickly enough. Making modern contraception and abortion accessible and ensuring equal pay and opportunities for women and men are acceptable means, but “it will take a very long time to humanely reduce total population to a size that is sustainable.”
Ehrlich was inspired by William Vogt, an amateur ornithologist who published the bestseller Road to Survival, in which he coined the term “carrying capacity” to describe the relationship between the human species and the environment. Just as a ship can only carry a certain amount of cargo, Vogt argued, the planet cannot support more people than its capacity allows. He identified eugenics as the answer to the problem of overpopulation.
In fact, both Vogt and Ehrlich follow the theory of the economist Thomas Malthus (1766–1823), who argued that while the means of subsistence increase in an arithmetic progression, the population increases in a geometric progression. According to this theory, overpopulation will inevitably lead to a crisis of natural resources, while poverty, epidemics, or wars will intervene to regulate the balance between the number of inhabitants on the planet and the amount of resources available.
The idea that the shortcomings of the present and, especially, the future stem from uncontrolled population growth is still prevalent in expert discourse today, and is supported by a series of arguments and forecasts.
When numbers matter
According to Ehrlich’s calculations, the optimal global population size would be between 1.5 and 2 billion, allowing for population concentrations in urban areas as well as uninhabited wilderness areas, although the planet could support 4–5 billion people if they were content with small living spaces and reasonable food rations. However, the professor believes that over 7 billion would be too large and unsustainable for a finite planet.
The global population currently stands at 8.2 billion, with an average annual growth rate of 70 million. According to a report by the UN Department of Economic and Social Affairs, this figure is expected to reach 8.6 billion by 2030, 9.8 billion by 2050, and 11.2 billion by 2100.
The report also shows that, in about three decades, half of the world’s population growth will be concentrated in nine countries: India, Nigeria, the Democratic Republic of the Congo, Pakistan, Ethiopia, Tanzania, the United States, Uganda, and Indonesia.
John Wilmoth, director of the department that produced the report, says that the pace of population growth varies greatly: it is accelerating in Africa, where the fertility rate is high at 4.7 births per woman, and falling in Europe, where it has dropped to 1.6 births per woman.
With 11% of the world’s population already facing starvation, experts are concerned about the planet’s ability to sustain a growing population with dwindling resources.
Population growth under the microscope
A 2012 report by The Royal Society concluded that rapid changes in the size of the world’s population and unprecedented consumption of resources pose serious challenges to human well-being and the natural environment.
The report says that most of the global population growth in the next century will come from poorer countries, 32 of which are in Africa. In Africa alone, the population is expected to increase by 2 billion, according to Eliya Zulu, one of the 22 researchers who wrote the report and former president of the Union for African Population Studies. If fertility rates remain the same, the population could double, says Zulu, who insists that African women too desire access to contraception in order to keep families within their means.
The dual problem of population size and excessive resource consumption should be at the top of the political and economic agenda, the authors of the study conclude. However, they refuse to put forward a figure for a sustainable population, arguing that this depends on lifestyle and choices made.
A 2016 study coordinated by Theodore Lianos of the Athens University of Economics and Business emphasises that pessimistic views of the planet’s future are based on solid arguments, showing that population growth rates will exceed the planet’s regenerative capacity if current trends continue.
The study’s authors estimate the optimal world population at 3.1 billion, as they consider the Earth to be “heavily overpopulated.” The study’s disconcerting conclusion is that, given the ineffectiveness of family or state measures to reduce the number of births, “a strong international authority should be instituted and invested with sufficient powers to implement policies that would contribute to the reduction in world population.”
In contrast, specialists who are optimistic about the effects of population growth believe that numerical pressure will accelerate scientific progress. This will either involve finding substitutes for depleted resources or identifying new methods of extracting inaccessible resources. In a free society, shortages will always be resolved thanks to human creativity.
However, the downside of this optimistic approach is that it often ignores the accelerated consumption of natural resources that modern life entails. Therefore, before deciding that all environmental warnings are false alarms, perhaps we should take a closer look at our consumerist lifestyle.
When consumption becomes the reason for living
Journalist and author George Monbiot writes that campaigns about overpopulation are designed to divert attention (and shift the blame) away from our own environmentally damaging actions. This is an elegant way of evading responsibility, because, as Monbiot notes, “when there is almost nothing to be done, there is no requirement to act.”
In a 2015 article for The Guardian, Monbiot argued that we should be more concerned about the proliferation of livestock, since intensively farmed animals far outnumber humans globally.
He stated that while the global human population was increasing by 1.2% per year, the number of livestock was rising by 2.4%, meaning the planet would have to provide for 400 million more animals by 2050. Although the figures have changed since then, the core message still holds true.
Animal farming will require more land and account for almost half of all grain crops, contributing to food shortages in poor areas of the world where people rely on grain to survive.
Developed countries have an increasingly large ecological footprint: Europeans use 4.9 hectares per person, and Americans use 7.8 hectares per person, despite the fact that the available global biocapacity per person is only 1.8 hectares. If everyone on the planet consumed resources at American levels, it would take four to five Earths to sustain the demand.
Further proof that our lifestyle is unsustainable comes from the waste with which we are suffocating the environment. In a single century, the amount of waste produced by the world’s cities has increased tenfold, and estimates show that it will double by 2025—the year when we will throw away enough waste to fill a convoy of trucks about 5,000 kilometres long every day.
The volume of food waste suggests that waste, rather than overpopulation, is responsible for the world’s food shortages. More than a third of the food produced worldwide ends up in landfill, while a quarter of this could feed 870 million people suffering from starvation.
Furthermore, the evidence that we are responsible for the waste that is in stark contrast to the shortages experienced in underdeveloped cewcountries, as well as the planet’s limited resources, is supported by a substantial body of research. Many experts argue that the blame for the planet’s impoverishment should be placed on the greed of those who have prospered rather than on those who have experienced hardship.
In defence of the population
“Overpopulation is not the problem,” argues Professor Erle Ellis of the University of Maryland, who rejects Vogt’s idea that the planet has a carrying capacity.
Although he once believed in classical population mathematics, which proves that populations must have a numerical limit in order to survive on a finite planet, Ellis says that coming across the theories of Danish economist Ester Boserup changed his perspective. Boserup, who worked for the United Nations in low- and middle-income countries, challenged Malthus’ conclusions in her book The Conditions of Agricultural Growth: The Economics of Agrarian Change under Population Pressure.
Drawing on her observations of how agriculture developed in countries that experienced rapid population growth, Boserup argues that the challenge of feeding more people motivates improvements in food-growing methods and the development of new technologies that enable higher agricultural yields. This occurred during the Green Revolution, which took place between 1943 and the late 1970s and saw agricultural production become industrialised in developing countries.
In an article for the Population Research Institute, Steven Mosher and Anne Morse argue that overpopulation cannot be responsible for the lack of resources, suggesting that it is merely a myth used to cover up our wasteful habits.
They base their argument on a 2012 study coordinated by Eric Holt Giménez, titled “We Already Grow Enough Food for 10 Billion People … and Still Can’t End Hunger.” The study suggests that food shortages are not the result of human overcrowding, but of inequality and poverty. Mosher and Morse quote the humanitarian organisation Oxfam: “Famines are not natural phenomena, they are catastrophic political failures.”
While acknowledging that water scarcity is a serious humanitarian problem, the authors emphasise that this crisis is not caused by overpopulation either. Karen Bakker, director of the Program on Water Governance and Geography at the University of British Columbia, pointed out that water is one of the most difficult substances to transport due to the associated costs. Therefore, “we need more dams, canals, and pipelines, not more abortion, contraception, and sterilisation,” Mosher and Morse add. According to the authors, it is not population growth in Africa that should concern us, but the decline in fertility in Europe. A UN report entitled World Population to 2300 warned that, if European fertility rates do not change, half of the continent’s countries would lose 95% of their population over the next three centuries.
We tend to blame poor people in Africa for having many children, but the elephant in the room is our own irrational consumption, writes Fred Pearce, author of “The Last Generation: How Nature Will Take Her Revenge for Climate Change.”
While population growth can cause local environmental crises or hinder a country’s economic development, the trigger for a global crisis lies with us, “the overconsumers, whose numbers are largely stable but whose appetites seem infinite.”
Consumerism does not meet legitimate needs, but seduces us with the promise of filling non-economic voids in our lives, says Annie Leonard, director of Greenpeace USA. Our consumer selves have become so overfed that we can no longer address important issues such as global warming except in terms of consumption: “I should buy this instead of this,” when the real solution is to walk away from the products you don’t need, she emphasises.
The dilemma of a generation: the lives of others versus our own comfort
Population stability or decline is not a panacea as long as consumption continues to rise, says Charles Eisenstein, author of The More Beautiful World Our Hearts Know Is Possible. He argues that if the world’s population had the lifestyle of an Indian villager, 12 billion would not be too many; however, to live up to the standards of the middle class in the United States, 2 billion people would already be an unsustainable number.
Under these circumstances, we will not be able to avoid making a choice; however, our moral sense must guide it, not our appetite for more. According to World Bank estimates, more than 1 billion people will belong to the middle class by 2030 (a spectacular increase from 400 million in 2005). However, the planet will not cope well with this change if these people consume meat or drive cars in the same way as Americans, as journalist and writer Robert Kunzig points out in an article for National Geographic.
In fact, the renowned ecologist E.O. Wilson was asked by the researcher David Suzuki how many people the planet could sustain indefinitely. His answer was: “If you want to live like North Americans, 200 million.”
Speaking about the choices that must be made when fewer resources are shared among more people, French demographer Hervé Le Bras noted: “Eating less meat seems more reasonable to me than saying, ‘Have fewer children!'”
This is especially pertinent given that the discussion is about restrictions that should be imposed on others—the planet’s poor—and as Stephen Pacala, director of the Environmental Institute at Princeton, calculated, the richest half a billion people on the planet (i.e. 7% of its inhabitants) are responsible for 50% of the world’s carbon emissions, while 50% of the world’s population is responsible for only 7%. As Pearce points out, we worry excessively about the two billion people who will be born in poor areas of the world, yet we ignore the fact that the carbon emissions of one American are equivalent to those produced by 20 Indians, 40 Nigerians, or 250 Ethiopians.
Emphasising that he is not an expert in the field, journalist Brian Merchant writes that the way the issue of overpopulation is propagated makes him feel uncomfortable. It is as if we want to place the blame for real problems on our most disadvantaged fellow human beings in order to absolve ourselves of responsibility for failing to find solutions to crises we have created.
Life is built on a foundation that is more robust than any mathematical calculation
David Bier, an analyst at the Cato Institute’s Center for Global Liberty and Prosperity, says that the issue of managing resources so that no one suffers should not be discussed in mathematical terms. Although he was involved in discussions and projects related to reducing fertility in poor countries in the late 1960s, Bier says he experienced a turning point when something reminded him of the words of a Jewish chaplain eulogising the dead on the battlefield on the island of Iwo Jima during World War II: “How many who would have been a Mozart or a Michelangelo or an Einstein have we buried here?”
Bier re-evaluated his stance, deciding that it was not his place to prevent the birth of a future Mozart, or indeed any child who might have brought “joy to his or her family and community.”
He believes it is wonderful to give people the opportunity to expand their families as much as they want or can afford, and that it is cruel to manipulate or coerce them into doing something they do not want to do.
Bier points out that the lack of respect for human life permeating all the approaches of specialists talking about the danger of overpopulation is disconcerting, analysing Ehrlich’s bet, modelled on Pascal’s.”If I’m right, we will save the world [by curbing population growth]. If I’m wrong, people will still be better fed, better housed, and happier, thanks to our efforts. Will anything be lost if it turns out later that we can support a much larger population than seems possible today?” This is Ehrlich’s bet, which Bier considers cynical, as long as the stakes are not its author’s life.
The analyst admits that he fails to see the logic in people being horrified at the starvation of a comparatively few people in a faraway country yet positively gleeful at the thought that “a million or ten million times that many lives will never be lived that might be lived.”
Although the issue of overpopulation may seem to be an economic or environmental problem, it ultimately has a substantial ethical dimension. In the 1970s, environmentalist Garrett Hardin used the metaphor of a lifeboat to represent wealthy nations surrounded by poorer populations. He argued that because the lifeboat had limited capacity, admitting too many people would have meant certain death for the existing passengers.
However, Pearce points out that the metaphor says nothing about the fact that the privileged people on board had taken up ten places each. Nor does it address the fact that our artificially amplified needs constantly and relentlessly devalue the lives of those who suffer and die in a world separated from us by an ocean of selfishness.
