Earth’s population is approaching seven billion at the same time that resource limits and environmental degradation are becoming more apparent every day. Rich nations have long assured poor nations that they, too, would one day be rich and that their rates of population growth would decline, but it is no longer clear that this will occur for most of today’s poor nations. Resource scarcities, especially oil, are likely to limit future economic growth; the demographic transition that has accompanied economic growth in the past may not be possible for many nations today. Nearly 220,000 people are added to the planet every day, further compounding most resource and environmental problems. The United States adds another person every eleven seconds. We can no longer wait for increasing wealth to bring down fertility in remaining high fertility nations; we need policies and incentives to stop growth now.
Much has been written about population growth since the first edition of Malthus's famous essay was published in 1798. However, an underlying truth is usually left unsaid: population growth on Earth must cease. It makes more sense for humans to bring growth to a halt by adjusting birth rates downward in humane ways rather than waiting for death rates to move upward as the four horsemen reappear. Those who think it inhumane to control human fertility have apparently never experienced conditions in Third World shanty towns, where people struggle just to stay alive for another day.
In 1970 Norman Borlaug won the Nobel Peace Prize for his work on developing new plant strains that formed the basis for the Green Revolution that began in the 1960s. However, in his Nobel acceptance speech Borlaug perceptively commented that:
There can be no permanent progress in the battle against hunger until the agencies that fight for increased food production and those that fight for population control unite in a common effort. Fighting alone, they may win temporary skirmishes, but united they can win a decisive and lasting victory to provide food and other amenities of a progressive civilization for the benefit of all mankind.
That was four decades ago. During that time the world's population increased by more than three billion and the struggle to feed, clothe, house, and educate ever-growing numbers of people continues. "Temporary skirmishes" seem persistent, if not permanent.
Writers sometimes confuse population issues. For example, in his post, "The Population Bomb: Has It Been Defused?", Fred Pearce wrote that "The population bomb is being defused at a quite remarkable rate." He conflates rates of growth with actual numbers. It is true that the rate of population growth worldwide has declined since 1970. However, the base population has grown by more than three billion; thus we currently add 80 million or more people to the planet each year. That is hardly "defusing" population growth!
Writers may sometimes have short memories when they write about population growth. Fred Pearce's post at "Consumption Dwarfs Population as Main Environmental Threat" is one example. George Monbiot's post on "The Population Myth" is another. Both authors seem to have discovered that our rate of consumption is an issue, so both play down population numbers and focus on our consumption habits. Neither mentions the work of Paul Ehrlich and his I = PAT equation, where I represents our impact on the Earth, P equals population, A equals affluence (hence consumption), and T stands for technology.
Both population and consumption are parts of the problem - neither can be ignored and both are exacerbating the human impact on Earth. More distressing, however, is that many among us don't even see that there are problems created by both growing populations and increasing affluence bearing down on a finite planet. To pretend that another 80 million people added to the planet each year is not a problem because they are all being added to the world’s poor nations makes no sense at all. Many of them will end up in rich nations by migrating, legally or illegally, and all will further compound environmental problems, from strains on oil and other fossil fuel resources to deforestation and higher emissions of CO2 and other greenhouse gases. As Kenneth Boulding noted decades ago, "Anyone who believes that exponential growth can go on forever in a finite world is either a madman or an economist".
Population, consumption, and greenhouse gas emissions will continue to grow until we either face up to the fact that there are limits on our finite Earth or we are confronted by a catastrophe large enough to turn us from our current course. If Chinese, Indians, and others in the poorer world had consumption levels that rose to current western levels it would be like Earth's population suddenly increasing to 72 billion, according to Jared Diamond, who then wrote that:
Some optimists claim that we could support a world with nine billion people. But I haven't met anyone crazy enough to claim that we could support 72 billion. Yet we often promise developing countries that if they will only adopt good policies - for example, institute honest government and a free-market economy - they, too, will be able to enjoy a first-world lifestyle. This promise is impossible, a cruel hoax: we are having difficulty supporting a first-world lifestyle even now for only one billion people.
This promise is often made by people who believe that that alone will stop population growth via the demographic transition, conveniently forgetting about such exceptions as China. As Tom Athanasiou argued, in Divided Planet: The Ecology of Rich and Poor, "In a world torn between affluence and poverty, the crackpot realists tell the poor, who must live from day to day, that all will be well in the long run. Amidst deepening ecological crisis, they rush to embrace small, cosmetic adaptations."
The widespread acceptance and political influence of modern neoclassical economics is a central part of our global problem. In one widely used economics textbook, Principles of Economics, Greg Mankiw wrote that “A large population means more workers to produce goods and services. At the same time, it means more people to consume those goods and services.” Speaking for many neoclassical economists, Tim Harford concluded, in The Logic of Life, that "The more of us there are in the world, living our logical lives, the better our chances of seeing out the next million years." The absurdity of Harford's statement must be recognised and challenged.