Next five years the key to peak of population

STEVE CONNOR

Science Correspondent

What happens in the intimacy of people's sexual relations in the remaining years of the second millennium will be critical in determining the maximum number of people living in the world by the middle of the next century.

Demographers say the world's population will peak in about 50 years but they cannot put an exact number on it, only that it will be between 7.9 billion and 11.9 billion - nearly twice the present 5.7 billion.

Although birth rates are slowing, the number of births will continue to rise as children enter their reproductive years. The availability of contraceptives and their cultural acceptance will largely determine the family size of these new reproductive recruits.

According to the United Nations' State of the World Population report, published yesterday, the world population is increasing by 86 million each year. This annual increase is likely to remain until 2015.

Nafis Sadik, executive director of the UN Population Fund, says the world's population will reach a plateau in the middle of the next century. The actual total reached depends on how well we do in the next decade in implementing the programme of action of the Cairo population conference last year.This envisages spending about $17m in 2000, increasing to $21bn by 2015, on family planning in the developing world.

Although worldwide contraceptive use has increased five- fold since 1969, availability in the developing world continues to be varied. Dr Sadik, an obstetrician, said death during childbirth was between 15 and 50 times greater for women in the developing world than in the West. Half a million women die as a consequence of pregnancy and childbirth, mainly because of the unavailability of contraceptives.

The UN Population Fund estimates that 350 million couples worldwide lack access to ''a full range of modern family planning services'' and 120 million more women would use contraceptives if they were available, affordable and acceptable.

Dr Sadik welcomed the Pope's letter of ''apology'' to women, published yesterday, but criticised the Vatican's continued reluctance to accept the contraceptive rights of women. Until such rights were given attention, she said, the only role for women in many societies would be reproduction.