It is easy to scoff and to be cynical. But there are times when creating a bandwagon is the only way to get things done. Twenty years ago, simultaneous concerts in London and Philadelphia captured the biggest audience in music history, with 1.4 billion viewers, and forced the issue of Africa and famine relief literally on to the world stage.

It is easy to scoff and to be cynical. But there are times when creating a bandwagon is the only way to get things done. Twenty years ago, simultaneous concerts in London and Philadelphia captured the biggest audience in music history, with 1.4 billion viewers, and forced the issue of Africa and famine relief literally on to the world stage.

Now, a generation later, Bob Geldof has overcome his doubts about repeating the success of Live Aid and returned to the fray with plans for a new concert to dramatise the continuing problem of poverty and debt in the developing world, especially Africa. The aim is once again to arouse the world's conscience and to force global poverty onto the agenda at the summit of next month's G8 countries, attended by leaders of the richest nations, at Gleneagles.

One can mock the motives of many of those taking part, the fashion for celebrities and politicians sporting wristbands in aid of Make Poverty History and even the grandiose aim of such a campaign. But what's the point? The idea of making poverty a thing of the past is a noble ambition; it should also be achievable, given the prosperity of the richest nations. Indeed, the growing gap between rich and poor is little short of obscene. The tendency of a globalising world, and competitive trade environment, to marginalise the weak, to exploit the poor and to ignore the plight of the dispossessed is a terrible rebuke to all of us in the better-off parts of the world who have gained so much from the raw materials and the labour of the developing world.

Two decades ago, the public looked at the scenes of famine in drought-torn Africa, the fathers unable to provide for their families, the mothers unable to feed their dying children, the elderly unable to reach out even for water, and decided something had to be done about it. They gave their money to the aid agencies who were trying to help - and politicians were unable to ignore the groundswell of concern.

Today the focus has shifted from highlighting the pictures of the dispossessed to spotlighting the responsibility of the richer world for their misery, and seeking out the measures to root it out permanently. The compassion is still there, as we saw with the global response to the tsunami crisis. Now we need to see if the political will is there, too. There are hopeful signs of change. The Make Poverty History campaign is one positive indication. The Africa Commission, set up by the Prime Minister, to look into the problems and needs of Africa which reported last month, is another. And both Tony Blair and Gordon Brown deserve credit for their desire to fight for Africa and to put poverty at the top of the agenda when Britain hosts the G8 summit in Gleneagles, with measures to reduce debt and increase aid. They must not be deflected by domestic issues, White House intransigence or the unwillingness of the European Union to abandon protectionist economic policies.

Of course, as the Africa Commission concluded, Africans themselves have to bear their share of responsibility for the misery on their continent. Civil war, repression and environmental devastation have all contributed. But Western trade policies, our exploitation of raw materials and the meddling in African policies from the outside have played an even bigger part. Write off debt, increase aid and reform trade and you have a real chance of tackling the underlying causes of poverty in the world. Especially at a time when there are genuine grounds for optimism emerging across Africa.

"The reality is that only politics created this dilemma and only politics can resolve it," Geldof argues. For all his flaws, he deserves credit for returning to the battle. Now it is the turn of the world's leaders.