By Marcus Leach

Leading charity Oxfam has warned that the prices of staple foods will doubled in the next 20 years unless action is taken by world leaders to reform the global food system.

The charity, in its report 'Growing a Better Future', predicts that by 2030 the average cost of crops will have increased by between 120% and 180% - with half of that increase due to climate change.

Oxfam have called on world leaders to improve regulation of food markets and invest in a global climate fund.

"The food system must be overhauled if we are to overcome the increasingly pressing challenges of climate change, spiralling food prices and the scarcity of land, water and energy," said Barbara Stocking, Oxfam's chief executive.

Oxfam, in the report, highlight four key areas where citizens are already struggling to feed themselves:

- in Guatemala, 865,000 people are at risk of food insecurity, due to a lack of state investment in smallholder farmers, who are highly dependent on imported food, the charity says.
- in India, people spend more than twice the proportion of their income on food than UK residents - paying the equivalent of £10 for a litre of milk and £6 for a kilo of rice.
- in Azerbaijan, wheat production fell 33% last year due to poor weather, forcing the country to import grains from Russia and Kazakhstan. Food prices were 20% higher in December 2010 than the same month in 2009.
- in East Africa, eight million people currently face chronic food shortages due to drought, with women and children among the hardest hit.

The World Bank has warned that the continued rise in food prices is forcing millions of people worldwide into extreme poverty.

With problems in the Middle East and North Africa they say April's food prices were 36% above what they were a year ago.

Oxfam wants nations to agree new rules to govern food markets, to ensure the poor do not go hungry.

It said world leaders must:

- increase transparency in commodities markets and regulate futures markets
- scale up food reserves
- end policies promoting biofuels
- invest in smallholder farmers, especially women

"We are sleepwalking towards an avoidable age of crisis," said Ms Stocking.

"One in seven people on the planet go hungry every day despite the fact that the world is capable of feeding everyone."