Hunger in east Africa has been part of our consciousness for so long now – from the 1984 famine and Band Aid onwards – that it's hard to blame anyone who says they're tired of hearing about it. Against that backdrop, it's understandable that people can feel torn between humanitarian concern and a feeling of hopelessness – that whatever they give, and whatever aid agencies do, it will never be enough to make a real difference. So it's important to stress that we in the Red Cross, and others, are appealing now because the situation has reached a crisis point.

In some areas this is now the worst drought for more than half a century and the number of refugees from Somalia arriving in southern Ethiopia in search of food has exploded – from around 5,000 a month to 30,000 in the second week of June alone. People don't abandon their homes and livelihoods except as a last resort. It means they are desperate, and it's a recognised early indicator of famine.

In response, the UK government has pledged £38m in food aid to Ethiopia, and many charities, including ourselves, are appealing for emergency funds to help across the Horn of Africa region. There is absolutely no doubt that aid is urgently needed by millions of people caught up in an unimaginably desperate situation, and that donations made by people here in the UK will save lives. I would urge people to give, and to give as much as they can.

But will those donations mean people in east Africa are not in a similar position this time next year? That's harder to guarantee. In the Horn of Africa, regular droughts are a fact of life. But it's a complex web of factors – including conflict, food and fuel prices, and poverty – that can combine to cause the delicately balanced environment to tip towards scenes of desperate hunger like those we are seeing today.

This is a chronically vulnerable situation in which communities drift in and out of food crisis. One of the things that will make a long-term difference in this region is to help people become more able to cope with these fluctuations. The Red Cross has been working on improving resilience across the region. The Ethiopian Red Cross is running a food security programme that incorporates environmental rehabilitation, development of water access, and promotion of income-generating activities for communities. The Kenyan Red Cross has rehabilitated boreholes and carried out pre-crisis distributions of seeds, greenhouses and livestock to help people increase their resilience. A recent British Red Cross programme in urban areas of Djibouti provided small cash loans to help vulnerable families build up small businesses and earn enough money to buy food.

Today's situation is so dire that in many cases emergency food aid is the only realistic option. But, while it undoubtedly saves lives, it doesn't help build resilience, and can, in fact, destabilise local markets and lock families into dependency. Lifesaving support needs to begin months and years before crisis arrives, supporting people during the good times so that when the bad times strike they have the reserves to carry themselves through.

But, if it's difficult to convince appeal-weary donors to give during a full-blown emergency, it's even harder to garner financial support when rains have fallen, crops are growing and livestock is multiplying, when families, often still recovering from the last crisis, need support to be able to fully capitalise on the favourable conditions presented to them. But it is exactly those times when this longer-term work must be done to try and genuinely change the prospects for communities in the Horn of Africa.

Today, support with longer-term benefits to help people recover and improve their livelihoods – helping people grow crops and raise livestock, and improve long-term access to water – will be rolled out alongside emergency food aid. But much of that can only be funded thanks to money raised on the back of this acute crisis. We in the aid sector must do better at making the case for investment at the times when there are no distressing images to show, or harrowing stories to relate.

Emergency food aid appeals save lives, but they don't solve the root problem. That requires a different, less sensational engagement with the media, with government and with the public – and it needs to be achieved before any of us are able to offer real solutions to extreme hunger in Africa.