I am still not sure why, as I knew comparatively little about its work around the world. I knew that the UN was founded after the Second World War to promote peace and co-operation between nations, and that it would endeavour to do this not just through diplomacy but by promoting equality, freedom and the eradication of poverty world-wide. UNESCO was to play its part by promoting international co-operation and the sharing of knowledge and expertise in education science and culture.
However, by the 1970s, it was generally felt that UNESCO had lost its way and become bureaucratic and ineffective. This led, in the 1980s, to the UK's withdrawal from UNESCO. To most people, the commitment before the last election, to rejoin UNESCO was rather obscure and the fact that we have now rejoined has gone largely unnoticed.
My task as chair of the new committee is to convince the people of Britain - especially teachers, pupils and parents - that UNESCO's aims and programmes will benefit not just developing countries but this country too. This is not an easy task given the pressures on schools which tend to squeeze out such issues as world citizenship and the problems other countries have in education.
However, the reformed UNESCO has united behind a powerful vision and commitment to "Education for All" by the year 2015. There are six goals to try to achieve this aim. They are: primary education, access, early years, adult literacy, gender and quality. These may sound similar to the UK's education priorities but in a world context they have a very different meaning.
Primary education doesn't mean 85 per cent of children achievig the average for their age in their key stage 2 SATs. It means that up to pound;5 billion a year will be needed between now and 2015 to get all primary-aged children into school. Access isn't an issue about the socially-excluded minority. More than 113 million primary-aged children do not go to school because there is no school for them to go to. Gender doesn't mean whether girls or boys do better at GCSE. It means that in parts of the world where there are not enough school places to go around, the boys go to school but the girls do not.
In Africa, and increasingly in South Asia, efforts are undermined by the HIV-Aids epidemic. In the worst-affected countries, 10 per cent of teachers are expected to die over the next five years and the proportion of school-aged HIV orphans will rise to more than 20 per cent in the same period.
In a recent statement, "Harness the Power of Education", leaders of UNESCO, UNICEF and the World Bank argued a compelling case for making good-quality education universally available.
"No country has ever achieved sustained economic growth without reaching the critical threshold of literacy for its population," it said. To highlight these issues, UNESCO UK plans to hold conferences and seminars, beginning in Birmingham on October 5 - World Teacher's Day.
An important message will be that children growing up in this country should consider themselves citizens of the world and be informed and concerned about world poverty and the lack of basic education which is the lot of millions of children in other countries. Although this can never be an absolute priority, we have a moral obligation to ensure our children are exposed to these issues.
Christine Whatford is director of education for Hammersmith and Fulham.