It's that time of year. Through the letter box come glossy gift supplements; junk mail invocations to eat, drink and get spending; charity Christmas cards and pictures of skeletal African children. We are more cynical than in 1984, when Band Aid's "Do They Know It's Christmas?" raised millions of pounds from the public for starving Ethiopians; today, we assume that famines become evident in December only because it is a good time for charities to raise money.
Yet a UN-backed global appeal launched this month is for a humanitarian crisis as grave as any we have seen in decades, with more than 14 million people in seven southern African countries threatened with starvation right now, 11.2 million people in Ethiopia who need food aid - right now, and for at least a year to come - plus a further three million in Ethiopia expected to be in urgent need of aid in the early months of next year.
Such statistics swim formlessly before our eyes - didn't rich country ministers recently pledge in Rome to reduce by half the 800 million people threatened with hunger worldwide? Is the crisis worse in southern Africa, where seven countries that have generally been able to feed themselves face serious food shortages, but with neither the experience nor the infrastructure to move relief aid around the region? Or in Ethiopia, where food crises are endemic so that even in a year of good harvests, five million people may be in need of food aid?
We know both too much and too little to answer such questions. After almost two decades of humanitarian aid, economic carrots and sticks from the World Bank and International Monetary Fund, and the liberalisation oxymoronically imposed by the World Trade Organisation, we expect things to be better. We keep hearing that they will be. But in absolute terms, the world's most desperate people are poorer, sicker and hungrier than ever.
The only reason their numbers remain more or less constant is that many more are dying younger, partly as a consequence of that other continuing humanitarian crisis - the global Aids epidemic. Last month, UN figures revealed that 30 million people throughout Africa are now infected with the virus. Their chances of survival are negligible while WTO rules stop poor countries producing or importing cheap versions of patented life-saving drugs.
When pictures of dying children were shown on television in October 1984 - the "Band Aid" famine - some eight million Ethiopians were threatened with starvation. The total figure for those at risk in Africa now may be four times that. Yet Africa's current cry for help is barely heard. At the beginning of December, the World Food Programme reported that only half the amount of grain needed in southern Africa had so far been donated. The WFP predicts that it will run out of food for the region by January unless more countries put money on the table. Meanwhile, informed or concerned members of the public have had little to respond to. The Disasters Emergency Committee, through which the leading aid charities such as Oxfam, Save the Children and Christian Aid co-operate to raise funds for such crises, has launched a muted appeal for the threatened southern African countries. The committee has no appeal for Ethiopia, though individual charities are running their own.
The committee and individual aid agencies are in an unenviable situation. If they sound the alarm before people are dying, they will be accused of crying wolf and generating compassion fatigue. There are few plaudits to be earned from averting crises, although that is obviously the optimal outcome. They face equal condemnation if they appear to have been silent when pictures of dying children hit our television screens, as happened in 1984.
Motivated by what he bluntly described as the obscenity of the rich watching the world's poorest die before their eyes, Bob Geldof, then the lead singer in the Boomtown Rats, flew out a planeload of journalists to Ethiopia to see the feeding stations for themselves and press-ganged other celebs to join him in recording a Christmas song. At the time, it was the most successful single ever and, along with subsequent Live Aid concerts, helped to raise around $100m. Geldof may have helped to save as many as seven million lives and, for a while, put global inequality at the top of the political agenda.
The legendary episode has nurtured the view that the media are key to raising funds for humanitarian crises. But it is far from clear what makes some emergencies "noisy" - Kosovo in 1999, for example - while others whose consequences are as bad remain "silent". Geldof engaged public attention after the BBC's Michael Buerk and the late Mohamed Amin, a Kenyan cameraman, had delivered a harrowing film of starving Ethiopians. Yet the facts of a coming famine had been known and reported in the British press long before the pop star's Band Aid initiative. As Paul Harrison, an independent film-maker, and Robin Palmer, a historian of Africa, write in News Out of Africa: Biafra to Band Aid, published soon after the famine, the BBC had asked Buerk and Amin to go to Ethiopia as early as July 1984. Amin was unavailable, having already been contracted to film Brooke Shields on holiday in the game parks of Kenya as part of the television series Lifestyles of the Rich and Famous. Only months later were both available to make the crucial film.
Harrison and Palmer record the despair of the Ethiopian Relief and Rehabilitation Commission as it waited for a response to its appeal for aid throughout early 1984: "I cannot overemphasise," a commissioner told them, "the growing sense of shock that my staff and I felt when we realised that first our March appeal and then our August appeal had failed, when the days of indifference turned into the months of apathy, especially when we could see that our predictions [of country-wide famine] were turning horribly true."
If simple press coverage had been the key factor, then there would have been an earlier response to the 1984 crisis. Research by the humanitarian policy group of the Overseas Development Institute and recent analyses from other humanitarian workers, such as Fiona Terry of Medecins sans Frontieres, suggest that we exaggerate the role of the media.
At a conference in Copenhagen in October on "forgotten crises", funded by the European Commission's Humanitarian Aid Office, a group of Danish researchers analysed press coverage and donor response to the major emergencies of the past few years and concluded that the security concerns of important donors such as the US or Europe had a far greater impact on public sympathy than press coverage, from the overfunded Kosovo and Afghanistan operations to the underfunded emergencies of Angola and Sudan.
But there is another, more important factor in our inability to comprehend and deal equitably with global crises. Globalisation was to be the salvation of the poorest countries. The global trading regime policed by the World Trade Organisation was to lift the poor out of poverty. Our markets were to be open to their produce. They would get fair prices for their coffee, tea and other exports.
But this hasn't happened, either. Global inequality has increased. The poorest have been forced to "liberalise" but have been denied access to rich-world markets. Prevented from protecting their own farmers, they have had to compete with the ever-more-heavily subsidised producers of the richest trading blocs. Meanwhile, the European Union and the United States have increased agricultural subsidies to their farmers, to the calculable detriment of the farmers of the poorest nations.
Ethiopia provides a poignant example. Its major export is coffee. The rich world is drinking more coffee than ever, but the price this year fell - in a market controlled by buyers - by 40 per cent, to a 30-year low. Ethiopia could do nothing.
If international market forces reduce countries to poverty, the solution too must be global. In a new book on global inequality, World Poverty and Human Rights: cosmopolitan responsibilities and reforms, Thomas W Pogge notes that the number of people in poverty has remained constant since 1987, while global inequality has continued to increase. Remarkably, he finds something to celebrate in this. Since the fifth of the world's people living in rich countries are collectively some 74 times richer than the fifth in the poorest (they were 30 times richer in 1960), he argues, we are now far more able to lift the desperately poor out of poverty. In other words, the rich are so much richer that their ability to alleviate the suffering of the poorest has never been greater.
If globalisation means anything, Pogge concludes, it must be that we take global injustices as seriously as injustices within our national borders.
In the coming months, we are unlikely to be spared images of starving and dying men, women and children in Africa. Only a radical new vision of justice to our fellow global citizens can interrupt the terrible and increasing regularity with which such crises recur. We should stop indulging in hopelessness. Poverty, disease and famine are, indeed, ever-present, but what has changed for the better is our ability to do something about it.
The World Food Programme's Africa Hunger Alert (www.wfp.org/africahungeralert/index.html ) provides updates on the crisis and information with which to lobby governments.
Donations can be made to the Disaster Emergency Committee's Southern Africa Crisis Appeal (www.dec.org.uk ) or Oxfam's Ethiopia Appeal (www.oxfam.org.uk/donation/  ethiopia2002.html). Christian Aid accepts donations for Ethiopia on 08080 005 005
Gideon Burrows on the business of charities, page 86