In 1972, the world’s first UN Conference on the Human Environment, in Stockholm, failed to even discuss human population. During the meetings, Paul Ehrlich, author of The Population Bomb, urged the delegates to consider ways to mitigate human population growth, as a driving force of ecological destruction.

Barry Commoner, the scientist who first detected radioactive Strontium-90 in children’s teeth, argued against Ehrlich, insisting that human population growth did not pose a critical environmental threat. Technology, he believed, would allow us to feed billions more people, and the real issue is wasteful consumption by the rich.

Ehrlich agreed about excessive consumption, but maintained that sheer population growth would degrade the planetary ecosystems and lead to humanitarian and ecological catastrophes. He urged environmentalists to advocate a global contraception drive to reduce unwanted pregnancies and the human fertility rate. Ehrlich’s proposals, however, collided with cultural, political, and religious resistance. The Stockholm conference avoided discussing population, and the environmental movement since 1972 has almost entirely ignored human population growth. Nevertheless, the nagging issue remains, 36 years and three billion people later.

Denial

Some resistance to discussing population reflects the common-sense reluctance to blame the world’s poor for our environmental problems. Most environmental groups have focused on the excesses of consumer societies, wilderness protection, pollution, and species loss, all valid issues. China’s response to burgeoning population, the “one-child-per-family” policy, appeared like totalitarian control over personal freedom. Ultimately, however, the greatest obstacle to addressing population growth has been religious and cultural hostility to contraception and women’s rights.

Growth advocates – real estate developers, retailers, and others who profit from population growth – insist that our communities can “grow forever.” Head cheerleader for this group has been Julian Simon, a corporate lobbyist in Washington, D.C. In 1995, Simon wrote:

“We have in our hands now … the technology to feed, clothe, and supply energy to an ever-growing population for the next 7 billion years. … Even if no new knowledge were ever gained…we would be able to go on increasing our population forever.”

Simon – out of deception or ignorance – misrepresents the simple truth about organic growth. Any percentage growth, whether stable or variable, like compound interest in a bank, has a doubling time, and numbers reach extremely values after several doublings. Even if the current population growth rate of 1.14% could be reduced to half a percent, 0.5%, then human population would double every 140 years. After five doublings, 700 years – somewhat shy of “forever” – world population would be 32 times today’s 6.7 billion, that is, over 200 billion people. This is not remotely possible. Simon may secretly understand the mathematical certainty of this impossibility, but he hopes his audience can’t.

Optimism and facts

While the advocates of eternal human expansion deny the limits to growth, even environmental and government agencies often avoid discussing how to stabilize or reduce human population. For example, the inspiring UN Millennium Development Goals – eradicate hunger and poverty; reduce child mortality and disease; achieve gender equality, maternal health, universal education, and sustainable development – never mention stabilizing population.

The notion of “sustainable growth” became popular with the 1987 United Nations Brundtland Report. Presumably with good intentions, the report suggests: “What is needed now is a new era of economic growth … that is forceful and at the same time socially and environmentally sustainable… Sustainable development can only be pursued if population size and growth are in harmony with the changing productive potential of the ecosystem.”

The report does not explain what it means by “sustainable,” the “changing productive potential” of an ecosystem, or how population could grow “in harmony” with this changing potential. However, none of these ambiguous ideas change the laws of nature. All growing organic communities – bacteria in a petri dish, mussels on a tidal shelf, or humans on a planet – eventually meet physical limits, stop growing, and reach maturity.

Dr. Albert Bartlett, Emeritus professor of physics at the University of Colorado, points out, “Any growth after maturity is either obesity or cancer.”

In the natural world, species growth ends in either a stable homeostasis with the environment, or in collapse. “Sustainable growth” is a nice idea, like “perpetual motion,” but equally impossible in the physical world. Bartlett – who urges scientists, environmentalists, and politicians to speak honestly about growth – explains, “The Brundtland Report’s discussion of ‘sustainability’ is both optimistic and vague. The Commission probably felt that, in order to be accepted, the discussion had to be optimistic, but given the facts, it was necessary to be vague and contradictory. … Sustainable growth is an oxymoron.” 

Real solutions

In the book version of An Inconvenient Truth, Al Gore writes: “The fundamental relationship between our civilization and the ecological system of the Earth has been utterly and radically transformed by the powerful convergence of three factors. The first is the population explosion.” However, when he gets to his list of 36 things we can do to change society – efficient lighting, recycling – he never mentions population. Is there some reason not to address the “first powerful factor” that has transformed the environment?

We might understand that politicians and even journalists, who are notoriously poor at math, might struggle to understand these properties of living systems. Economists should understand the limits to growth, since most economists are decent math students, but most economists are employed by those who profit from growth and have little interest in natural facts. However, anyone who claims to be an ecologists or a scientist surely must grasp the simple laws of growth if we expect economists and politicians to understand it.

From time immemorial, human population rates grew steadily until about 350 BC, when urban crowding, disease, and war decimated human populations. A great “urban crash” lasted two millennia until the 1700s, when advances in medicine and sanitation allowed population growth rates to match ancient levels, a modest 0.2% per year. Thereafter, human population took off, reaching a peak rate of 2.2% in 1963, during the era of cheap fuel and massive resource extraction. Since then, the human growth rate has declined to 1.14% and continues to fall.

Growth economists like to claim this fertility rate falls because of rising global economic activity (GDP), but the evidence suggests otherwise. Population growth rates and GDP rose together prior to 1964. Since then, fertility rates have fallen to zero in many European countries, but not in the US or Saudi Arabia where religious and cultural restraints keep rates high. In the 1970s, fertility rates fell in Spain and Italy, not due to a sudden increase of wealth, but rather due to an increase in women’s rights and available contraception. In Columbia, fertility rates dropped from 6 to 3.5 in 15 years after contraception was made widely available.

Some people fear that talk of stabilizing or reducing population invokes totalitarian oppression, the China policy, or worse. Politicians cower at the thought of challenging religious taboos against contraception. However, the best, proven means to stabilize population are simple and offer other humanitarian benefits:

1. Achieve women’s rights worldwide, and

2. Make contraception available.

The last doubling

Over the last 200,000 years, human population has doubled 19 times, from about 10,000 Archaic Homo sapiens to our present 6.7 billion. We have now entered the historic last doubling, which will not even reach completion. Human population will likely not reach 12 billion and will stop growing in this century for the first time in history (except for brief periods during the urban collapse and plagues).

Unless humanity experiences a cataclysmic crash to speed up the process, population growth rates will reach zero sometime between 2050 and 2080. By that time, there will be about 10-billion people on the planet. Currently, at 6.7 billion, 13%, 880 million, live at starvation levels, malnourished, and hungry. The UN attempts to feed about 75 million of these starving people (about 8%), but because of rising food prices, the UN announced this year that it could not even achieve that modest goal.

Since population growth will stop, the issue for humanity is whether we are clever enough to slow population by design, or if we simply let nature dictate the terms, which may not be pleasant for our children and grandchildren. Nature, in all her beauty and glory, is not sentimental. When nature steps in to stop growth, it does not offer niceties, as we may witness in the poorest, most ecologically degraded regions of our world, where 25,000 people starve to death every day.

Our regrettable hedging about population has proven unhealthy for the Earth. Since the first UN Environment Conference in 1972, three billion people have been added to the human load on our ecosystems. Both sheer population growth and excessive consumption contribute to the degradation of the ecosphere. Population growth in North America proceeds at about 1% per year, but since North Americans consume about 15-times the energy and resources of developing countries, this 1% growth translates into the world’s most urgent population problem.

Meanwhile, British physician Malcolm Potts estimates that 220,000 unplanned and unwanted conceptions take place every day, representing a massive “unmet demand for family planning.” If we wake up from the long denial about population growth, push governments to achieve women’s rights worldwide, make contraception available worldwide, and thereby reduce population growth to zero or below, we could save our progeny a lot of misery. Environmentalists should lead this change in attitude.

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See my Deep Green columns at Greenpeace International

See Dr. Albert Bartlett’s excellent video on exponential growth