Today, in the Horn of Africa, more than 13 million people are affected by one of the region's worst droughts in 60 years. Famine grips swathes of southern Somalia. Yet, drought does not need to become famine –nor should it ever be allowed to, either through system failure or through the kind of deliberate deprivation we are seeing in areas controlled by Al-Shabaab.

The hunger in the Horn of Africa is but a fraction of a needless global menace. There is more than enough food on the planet to feed everyone, yet today nearly one billion people will go hungry. I urge world leaders in rich and poor countries alike to invest the energy and resources necessary to win the battle against hunger –a key pillar of our efforts to achieve the Millennium Development Goals. Lasting solutions must cover the full spectrum of food security –from improving the resilience of smallholder farmers to deploying safety net programmes that help protect the most vulnerable.

This year's World Food Day highlights the issue of price volatility. For the world's poorest people, many of whom spend up to 80 per cent of their income on food, this can be devastating. In 2007-2008 food price inflation pushed some 80 million people into hunger. Recent food price hikes have propelled another 70 million people into extreme poverty.

We need to break the links between poverty, food insecurity and malnutrition. Families impoverished by price volatility risk seeing their babies' minds and bodies permanently damaged by malnutrition their children being taken out of school and put to work, and their income-producing livestock slaughtered for food. The answer is to put in place policies, like those advocated by the Scale Up Nutrition movement, to ensure all people have access to sufficient nutrition.

This month the world's population will top seven billion people. The world has the knowledge and the resources to end hunger we have the tools to ensure that the poorest are buffered from the impact of rising prices. Let us use them –now –to conquer hunger.