How severe weather impacts global food supply

Sometimes Jaria Faraj Ali is so hungry that she ties a scarf tight around her waist to make her feel more comfortable.

The Yemeni mother of six told the international aid group Oxfam that she has now resorted to begging because food prices are so high and she doesn't have an income.

And in Pakistan, 28-year-old Asif Masih says he has to work at two jobs to buy enough food. "I drive a taxi part time as well as work in an office because otherwise me and my family won't be able to eat," he told CNN.

Their stories of hardship are echoed across the globe from Tajikistan to Peru where a recent spike in world food prices has hit the most vulnerable, and particularly in countries that rely on imported food.

Rising food prices have been blamed on a number of factors -- for example, rising energy costs, changing land use for biofuel production, local conflicts, and an increasing demand for meat and dairy products.

But 2012's severe weather events around the world have led to low yields in nations such as the U.S. that export grain. Oxfam fears climate change is responsible and that impoverished people could be facing a future of high food prices driven by extreme weather trends.

Oxfam spokesperson Colin Roach said: "High and volatile food prices spell misery for millions of people like Jaria who face a daily struggle to put food on the table. This is man-made misery in a world which produces enough for everyone to eat."

A recent study commissioned by Oxfam into global warming and food prices, said: "Against a backdrop of rising populations and changing diets which will see global food production struggle to keep pace with increasing demand, the food security outlook in a future of unchecked climate change is bleak."