This morning, for example, 33 million children in Africa are unable to go to school because there is no school and no teacher.
Worldwide, the number of children unable to take the first steps in education is a staggering 75 million, 10 per cent of all children of primary school age in the world.
Even the children who do go to school are at risk of not learning because of a shortage of teachers. Some 4 million new teachers are needed by 2015 if every African child is to go to school in a class with no more than 40 students per teacher.
Even more troubling is that more than 774 million adults - one in four in the developing world - cannot read the instructions on a bag of fertiliser or a bottle of medicine. Hundreds of millions of adults are trapped in poverty because they do not have the skills to read and write - or the confidence to stand up against exploitation - because they cannot go to school or get the instruction they need.
If the rich countries of the world lived up to pledges made in 2000 and since, this situation could be dramatically improved.
African countries have shown the way forward in the past few years by kick-starting a social revolution which has seen school enrolments jump by 40 per cent since 1999. Their governments have abolished school fees, run campaigns in villages to promote girls' education and found ways to make school more affordable to the poor.
However, this progress is extremely fragile. While donors have supported some countries such as Kenya, Ethiopia or Tanzania, for example, generally their aid is too thinly spread and given too sporadically. Consolidating the gains made requires a much more concerted international effort.
In 2000, rich nations pledged that no country would be thwarted in its efforts to provide basic education to all for lack of funds. Yet aid to basic education falls far short of the estimated US$11 billion a year that is required to meet this goal. Aid to basic education in 2006 amounted to just US$5 billion, and overall aid fell by 8 per cent last year.
Nor is the aid that is forthcoming targeted at the countries most in need. The UN Secretary General's Africa Working Group says about 75 per cent of aid to basic education - about US$8 billion - should go to Africa. Both the G8 and the EU have pledged to increase significantly their support for the continent. Yet, in 2006, funding for basic education amounted to just US$2 billion.
It is time for donors to live up to promises and scale up funding; for even if recent pledges are met, aid will still only reach about half of what is needed each year.
The G8 summit in Hokkaido, Japan, is an opportunity for rich nations to show they are serious about achieving universal primary education. If all donor governments were to dedicate 10 per cent of their total aid to basic education, US$10 billion a year could become available by 2010. This is the commitment needed.
Three years ago at the Gleneagles summit, G8 countries pledged amid great publicity to increase their aid by 60 per cent by 2010. At this year's summit they must get back on track.
Too much time has already been lost. Too many promises have not been kept. Yet time is of the essence. Education is imperative for development and access to it is a moral responsibility. Answering this challenge will provide millions of citizens with the keys to improve their livelihoods and help to break the vicious cycle of disadvantage and poverty.
Koïchiro Matsuura
Director-General of UNESCO