HARSH weather, including droughts and floods, will drive up food prices in the future, international aid agency has warned.

In a report released on Wednesday, it said that the world’s vulnerability to further drought in the US could worsen, warning of a possible 140% increase in the price of maize "over and above the average price of food in 2030, which is already likely to be double today’s prices".

Weather conditions in Asia, a nationwide drought in India and flooding in Southeast Asia is expected to drive the world market price of rice up 22%.

Ernest Janovsky, head of Absa’s agricultural agribusiness positioning unit, told the Agriculture Outlook Conference in Pretoria on Wednesday the world’s food security challenges could be worsened by the diversion of food products or production resources to biofuels.

Mr Janovsky said food wastage worldwide was also serious. Current food wastage estimates of about 30% were due to a lack of proper storage facilities, he added, and this figure would not be reduced soon as governments were slow in investing in such agricultural infrastructure.

Oxfam’s report said drought and flooding were also expected to bring up the consumer price of maize "by as much as 120%" in Southern Africa.

This means the price of a 25kg bag of corn meal could rise from R152 to R335.

Tim Gore, a climate change policy adviser at Oxfam, said in the report that while all countries would feel the impact of the price hikes, "the poorest people will be hit hardest".

"The huge potential impact of extreme weather events on future food prices is missing from today’s climate change debate. The world needs to wake up to the drastic consequences facing our food system of climate inaction," Mr Gore said.

He said governments needed to cut down greenhouse gas emissions, increase investment in small-scale agriculture in poorer countries, and provide financial support for poor farmers who faced the weather challenge.

"Our planet is heading for average global warming of 2.5°C to 5°C this century. It is time to face up to what this means for hunger and malnutrition for millions of people on our planet," Mr Gore said.

The Food and Agriculture Organisation is also expected to release a report this week on the US drought’s impact on global food prices.