Alarm as world population enters a grey area

ON THIS crowded, trampled planet, one of the most vexing trends is something countless of us see when we look in the mirror: we are going grey. The United Nations has declared that the human population has hit 7 billion, and an expanding percentage of those people are in the market for reading glasses.

The ageing of the human race has been faster than anyone could have imagined a few decades ago. Fertility rates have plunged globally and life spans have increased. The result is a new age graph the pyramid, once with a small number of old folks at the peak and a broad foundation of children, is inverting. In wealthy countries, the graph already has a pronounced middle-age spread.

Longer life is a blessing of modern medicine and nutrition, while lower fertility corresponds to greater prosperity and education. Women have gained more control over their reproductive lives.

But the unexpectedly abrupt demographic transition has created economic upheaval. For the countries that hit the fertility brakes the hardest, the greying of society has become a full-blown crisis. They are suddenly desperate for babies. They need more workers to provide goods and services to huge numbers of pensioners.

The fertility rate in Germany, Italy, Spain, Greece and many other nations is less than 1.5 children per woman, dramatically lower than the "replacement" rate of 2.1 children. Japan (fertility rate 1.4) is already the oldest country in the history of the world, while China (1.5) is racing to get rich before it becomes old.

In far better shape is the US, with a fertility rate just slightly below replacement level. Immigration boosts the country's workforce. But the baby boom generation is storming the higher age brackets.

"There are many countries, more all the time, that are going to be looking at a population implosion rather than a population explosion," said Matthew Connelly, a Columbia University professor of history and the author of Fatal Misconception: The Struggle to Control World Population.

The ageing of the world will change cultures in myriad ways. People may have to extend their working lives far beyond the traditional retirement age.

Countries may start competing for immigrants. Vast numbers of people are already migrating from high-fertility countries to those which need workers.

The planet as a whole does not have a baby shortage. Every minute of every day, according to the Population Reference Bureau, the number of births exceeds the number of deaths by 158. But the growth is not spread out. Of that net increase, 154 are in the developing world.

It is unclear how big the human population will get. The most likely scenario, the UN said, will put the population at 10 billion at the end of this century and growing only modestly. But a relatively small boost in the predicted fertility rate could result in a world with 16 billion people a decrease could mean a drop to 6 billion.