Power to the people

In the 1970s, demographers made apocalyptic predictions of rapid population growth. Now they think numbers will actually fall within 50 years. Why? Fred Pearce reports

The women of Bangladesh are among the poorest, least-educated in the world. But they are in the forefront of a revolution that is amazing population scientists. In a single generation, they have halved the birth rate. On average, they have a little more than three children today, down from the six born to their mothers. Their daughters may have fewer than two.

They and hundreds of millions of other women could be setting the human race on a path toward demographic decline. Within 50 years, four-fifths of the world's women may settle for two or fewer children. And if that happens, babies will be so scarce that the world's population will be shrinking. Forget the population bomb: there may be a baby bust - a message that may go unnoticed following the publication today of the United Nations report on world population.

In much of southern and eastern Europe, women already have an average of just 1.3 children - way below the two or more needed to maintain populations. Now, large numbers of developing countries are heading that way, too, says Joseph Chamie, head of the United Nations population division in New York. He expects fertility rates in most of the developing world to drop by mid-century to around 1.85. Barring a vastly expanded life expectancy, this will inevitably lead to an eventual population decline.

Already 60 countries have fertility rates below replacement levels, from Europe and North America to East Asia and the Caribbean. Soon Thailand, Iran, Vietnam, and Sri Lanka will join them. Mexico and Turkey, Indonesia and Brazil, even India, will be there within 20 years. Muslim or Catholic, socialist or capitalist, rich or poor, women are electing not to have as many children. The implications, says Chamie, are "momentous".

It's a far cry from the apocalyptic population predictions of the Seventies, when the fear was of exponential population growth. Yet, even then, there were signs that the population bomb had been defused. Fertility rates have fallen steadily since the Fifties, when the average woman of the world had five children. Today she has 2.7.

Demographers have theorised for some time that the world would eventually follow Europe and North America on a path from a population explosion to stability. They call this path the "demographic transition". Populations first soar as better nutrition, sanitation, and medical science cut death rates, and then stabilize as people opt for fewer babies.

Until this year, the consensus was that the world's population, which quadrupled to six billion during the 20th century, would settle down by 2100 at between 10 and 12 billion. But the UN now projects that, after peaking at around nine billion in 2050, the world's population could start falling.

In many countries, the decline is already happening. Japan expects to have 14 per cent fewer people by 2050, Italy 25 per cent fewer, and Russia 30 per cent fewer.

Now, government concerns remain how to cope with the three billion extra people likely to be on the planet by 2050. But, beyond that, Chamie's projections are that there could be fewer people on the planet at the end of the 21st century than at the start - the first time that has happened since the Black Death of the 14th century.

What has changed demographers' thinking? First, they have dropped the notion that humans are "hard-wired" to have at least two children. Secondly, they have largely ditched the idea that certain levels of prosperity and education are required before women voluntarily reduce their numbers of babies. In the past two decades, ever-poorer countries have joined the trend for smaller families, says Tim Dyson of the London School of Economics. None is more startling than Bangladesh, which is still one of the poorest nations outside Africa. Equally unexpected is the discovery that most of the recent decline in fertility in India has been among illiterate women.

Some say that poor women only stop having babies if forced to by governments. That certainly happened in China, where the one-child policy is close to stabilizing the world's most populous country. But many countries with the fastest decreases in birth rates have had governments opposed to state-sponsored family planning. In Brazil, fertility rates have fallen from more than six to a little more than two in 40 years. In Iran, women have cut their fertility rate by two-thirds in less than 20 years.

Demographers say that, apart from the availability of contraception, there is another common factor in the countries with fast-falling fertility - women's emancipation. Even the very poor and ill-educated are starting to learn about the gains of women round the world, Dyson says. They are seizing their chance for a better life. And that doesn't have to involve babies.

Their chance came with the improved life-expectancy of children. "The enormous time, energy and emotion women used to spend on bearing and raising children, most of whom died before reaching adulthood, can now be spent on other things," says Griffith Feeney of the East-West Center in Hawaii. And, having seized their social and economic opportunities, women are questioning the need for parenthood altogether. "Getting married and having children are simply not as important as they used to be," Dyson says.

Not every country has followed the trend. Israel, Argentina and Malaysia have all kept fertility rates around three children per woman. The US has not plunged to low fertility levels, largely because of the influx of immigrants with higher fertility rates. And in many poor African nations, women still have six children or more.

These nations eventually may follow, but nothing is certain. A massive increase in poverty, a waning of female emancipation or a growth in religious fundamentalism might all cause family sizes to start growing again. Equally, the spread of HIV could cause even countries with high fertility rates to slip into demographic decline.

In Europe, the highest fertility rates are now in Scandinavia, where men and the state have accepted more responsibilities for bringing up children. Women there combine motherhood with a career in a way still not possible in southern Europe, says Peter McDonald of the Australian National University in Canberra. What he calls the "Mediterranean patriarchal model" seems more typical of the rest of the world. But if men worldwide began to remodel themselves to allow women to resume childbearing, the baby bust might be ended.

The new demographics suggest other social changes. Migrants could become a new power on the planet. Currently, refugees and economic migrants are ostracized. But, soon, as the supply of indigenous young adults slows in most countries, they will be in increasing demand.

And what of grey power? As childbirth declines, the world's elderly population is already growing twice as fast as the population in general. The average age today is 28; by 2050, it will be around 40. A fast-growing population of the elderly will put pressure on pensions and health services. But could it also herald a more conservative, less innovative world? Ben Wattenberg of the American Enterprise Institute has warned that global aging is "the real population bomb". But Theodore Roszak of California State University stated in his book The Longevity Revolution that we should herald the advent of an older, wiser world.

We have grown used to the idea that the future of humanity is threatened by overpopulation, mainly because of the drain on global resources. A declining population would certainly reduce such pressures, but it also may turn our world upside-down.