The world is getting older.

In the next 50 years, the number of older persons will nearly quadruple, growing from about 600 million to almost 2 billion senior citizens.

Today, one in every ten is 60 years and older. By 2050, one out of every five will be an older person, and by 2150, one third of the people in the world are expected to be 60 years of age or older.

In our fast ageing world, older men and women will increasingly play a critical role - through volunteer work, transmitting experience and knowledge, helping their families with caring responsibilities and increasing their participation in the paid labour force.

Senior citizens make major contributions to society. For instance, throughout Africa and elsewhere - millions of adult AIDS patients are cared for at home by their parents. On their death, orphaned children left behind (currently, 14 million under the age of 15 in African countries alone) are mainly looked after by their grandparents.

It is not only in developing countries that older persons' role in development is critical. In Spain for example, caring for dependent and sick individuals is mostly done by older people (particularly older women).

Such contributions to development can only be ensured if older persons enjoy adequate levels of health, for which appropriate policies need to be in place.

For further information see the UN Programme on Ageing;

World Population Ageing 2002 Wall Chart [PDF, 568KB]

"Ageing is a development issue. Healthy older persons are a resource for their families, their communities and the economy".

World Health Organisation Brasilia declaration on healthy ageing, 1996.

BBC News Listen - Scientists prepare to discover the secrets of a long and healthy life