Leading article: Twenty-five years after Band Aid

A quarter of a century on from the famine that mobilised Band Aid, Ethiopia faces another food crisis. There will be those who will seize on our report today to say: "See! Nothing can be done; foreign aid is a waste of money." The Independent on Sunday takes the opposite view.

In some ways, the history of Ethiopia since 1984 is a story of success. Despite civil war, political turmoil, the secession of Eritrea and economic crises, the terrible famine of that year has not been repeated. One of the main lessons, of the need for early-warning systems, has been learnt and acted upon.

That is why we are able to report today on the possibility of a food crisis later this year: the rains started three weeks late last month and the quantity of rainfall continues to be low. In the past 25 years, there have been periodic food shortages, but they have been anticipated and have not been allowed to develop into full-scale famines. The productivity of Ethiopia's agriculture has increased hugely: it is a perverse indicator both of the country's relative success and of its continuing problems that the population has doubled in that time.

But Ethiopia is still a society, an agricultural economy and an ecosystem on the edge. Already, one in six of its population is receiving food aid – half in return for work on community projects. Most of its subsistence farmers live a half-step ahead of starvation. It does not take much to tip such a poor country into crisis.

Here we come up against two ambiguities. One surrounds the word "famine". The Ethiopian government does not like it: it would imply that it has failed. Berhanu Kebede, Ethiopia's ambassador to Britain, insists that food reserves are adequate to cope with any contingency. That should not inhibit us from warning of the danger of famine. The risk is real.

Which brings us up against the other ambiguity: the danger of crying wolf. We do not yet know how bad the situation will be after the harvest in October. But now is the time to sit up and take notice, because it can take three months to transport food to remote areas of the country.

And there is an added complication that was not so well understood a quarter of a century ago: global warming is making the Ethiopian climate more fragile and unpredictable. Alex Renton today points out that the new Blackheath campers are right about one thing: climate change is now a central issue for the world's poor.

It is all the more important, therefore, that the leaders of the rich nations fulfil their pledge to provide funding for the UN's World Food Programme. The Ethiopian government may feel constrained in asking for help – although Mr Kebede has said that the international community "is not living up to its promise" – but we should not. Those who were inspired by the idealism of Live Aid – before this newspaper was founded – and those who celebrated the success of Live 8, which helped to secure the Gleneagles agreement four years ago, should redouble the pressure on world leaders to deliver.

Since 1984, our understanding of development economics has advanced. Bob Geldof was always explicit that Band Aid was a temporary, emergency mission, as its name suggested. Much of the work that followed was directed towards understanding how to build sustainable economies that could feed themselves. That learning process in this country informed the work of the Commission for Africa, which reported before the Gleneagles summit. It set out the terms of the deal: that African nations would focus on better governance in return for funding, not primarily for short-term food aid but for investment in greater capacity.

Again, we see the collecting tin as half-full rather than half-empty. Yes, half of the funds promised to the World Food Programme this year have yet to be forthcoming, but, as a result of Gleneagles, the reference level has been raised substantially. Money for UN programmes is always slow to be handed over, but half of a lot is better than half of not very much. And the promises have been made, and renewed at the G8 in Italy last month, so it is not as if we are trying to persuade politicians to produce new sums of money out of the blue.

A quarter of a century after Michael Buerk first roused the conscience of the British television audience with his unflinching reporting from the dry highlands of Ethiopia, it is time for the promises made in Italy last month to be called in.