THE United States and the United Nations disagreed over when the world would pass the six-billion mark. The Americans said the date was June 1998, but the UN placed it on October 12,1999.

The world's population has doubled since 1960. Now the rate is slowing, but it will take time to show, given the vast numbers of people of child-bearing age.

How about a lower forecast for the global population then?

The UN lowered its forecast for 2050 from 9.4 billion to 8.9 billion. This is due to the unexpectedly ravages of Aids in sub-Saharan Africa and parts of the Indian subcontinent and also the slow change of attitude in the developing world, which accounts for over 95 per cent of population growth. Women have more say on the timing and size of their families.

Also, the UN observes, demographic trends are diverse and diverging.

In China and most of the industrialised world, births and deaths are at or below replacement level. People in developing countries, are having fewer children - from an average of six in 1969 to three today.

But the population keeps on growing as more babies survive and the old live longer due to the advances in healthcare.