There are some problems so big and so entrenched it is easy to believe they will never be solved. Hunger is one of these problems. I doubt if there is a single moment in our history when all human beings have had enough to eat. Even today, in a world where it is possible to communicate across thousands of miles at a touch of a button, eight million people face chronic food shortages in East Africa. Around the world close to 1 billion men, women and children will go to bed hungry tonight. Yet a lifetime of experience has taught me that there is no problem so great it cannot be solved, no injustice so deeply entrenched it cannot be overcome. And that includes hunger. Hunger is not a natural phenomenon. It is a man made tragedy. People do not go hungry because there is not enough food to eat. They go hungry because the system which delivers food from the fields to our plates is broken. And now in this new age of crisis – with increasingly severe and extreme weather and dwindling natural resources – feeding the world will get harder still. So how did we get here? Our governments must shoulder a lot of the blame. Their policies and practices are propping up a broken system which benefits a few powerful companies and interest groups at the expense of the many. They have spent billions of dollars on biofuels companies and northern farmers but neglected the 500 million small scale farms which together feed one third of humanity. They have spent more then a decade debating climate change but pledged emissions reductions which put us on course for catastrophic warming. They have let the food markets get out of control and have denied women, who produce much of the world’s food, the right to land, resources and opportunities enjoyed by their male counterparts. But the future is not set – it is ours to shape. Today Oxfam is launching its new global ‘GROW’ campaign for a world without hunger. This is not based on the utopian musing of do-gooders and day dreamers. It is a very real plan based on the real achievements of forward thinking governments, companies and communities – for example the government and people of Brazil who together cut the number of hungry people by a half in just 15 years. However it does require a totally different approach to the way we produce and share food. Governments – especially the powerful G20 countries – must kick start the transformation. They must invest in poor producers and provide them the support they need to adapt to a changing climate. They must regulate volatile commodity markets and put an end to the policies which reward companies for turning food into engine fuel. And they must deliver a global climate deal to keep climate change in check. Of course many governments and companies will be resistant to change through habit, ideology or the pursuit of profit. It is up to us – you and me – to persuade them – by choosing food that’s produced fairly and sustainably, by cutting our carbon footprints and by joining with Oxfam and others to demand change. It is not going to be easy but nothing worth struggling for ever is. Archbishop Emeritus Desmond Tutu is an Oxfam Global Ambassador.