Food has never before existed in such abundance, so why are 870 million people in the world going hungry?
In purely quantitative terms, there is enough food available to feed the entire global population of 7 billion people. And yet, one out of every eight people is going hungry. One in three children is underweight. Why does hunger exist?
Natural disasters such as floods, tropical storms and long periods of drought are on the increase -- with calamitous consequences for food security in poor, developing countries.
Drought is now the single most common cause of food shortages in the world. In 2011, recurrent drought caused crop failures and heavy livestock losses in parts of Ethiopia, Somalia and Kenya.
In many countries, climate change is exacerbating already adverse natural conditions.For example, poor farmers in Ethiopia or Guatemala traditionally deal with rain failure by selling off livestock to cover their losses and pay for food. But successive years of drought, increasingly common in the Horn of Africa and Central America, are exhausting their resources.
Since 1992, the proportion of short and long-term food crises that can be attributed to human causes has more than doubled, rising from 15 percent to more than 35 percent. All too often, these emergencies are triggered by conflicts.
From Asia to Africa to Latin America, fighting displaces millions of people from their homes, leading to some of the world's worst hunger emergencies. Since 2004, conflict in the Darfur region of Sudan has uprooted more than a million people, precipitating a major food crisis -- in an area that had generally enjoyed good rains and crops.
In war, food sometimes becomes a weapon. Soldiers will starve opponents into submission by seizing or destroying food and livestock and systematically wrecking local markets. Fields and water wells are often mined or contaminated, forcing farmers to abandon their land.
When conflict threw Central Africa into confusion in the 1990s, the proportion of hungry people rose from 53 percent to 58 percent. By comparison, malnutrition is on the retreat in more peaceful parts of Africa such as Ghana and Malawi.
In developing countries, farmers often cannot afford seed to plant the crops that would provide for their families. Craftsmen lack the means to pay for the tools to ply their trade. Others have no land or water or education to lay the foundations for a secure future.
The poverty-stricken do not have enough money to buy or produce enough food for themselves and their families. In turn, they tend to be weaker and cannot produce enough to buy more food.
In short, the poor are hungry and their hunger traps them in poverty.
In the long-term, improved agricultural output offers the quickest fix for poverty and hunger.
According to the Food and Agriculture Organization (FAO) 2004 Food Insecurity Report, all the countries that are on track to reach the first Millennium Development Goal have something in common -- significantly better than average agricultural growth.
Yet too many developing countries lack key agricultural infrastructure, such as enough roads, warehouses and irrigation. The results are high transport costs, lack of storage facilities and unreliable water supplies.
All conspire to limit agricultural yields and access to food.
But, although the majority of developing countries depend on agriculture, their governments economic planning often emphasises urban development.
Over-exploitation of environment
Poor farming practices, deforestation, overcropping and overgrazing are exhausting the Earth's fertility and spreading the roots of hunger.
Increasingly, the world's fertile farmland is under threat from erosion, salination and desertification.
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