(NaturalNews) Riots and other forms of civil unrest have already broken out around the world in response to a global grain shortage and surging food prices.

According to data from the World Food Program and the early warning and global information system of the Food and Agricultural Organization, street protests and rioting over high food prices have broken out in Guinea, Indonesia, Mauritania, Mexico, Morocco, Uzbekistan, Yemen and West Africa in the past several months.

Prices of wheat and rice in particular have skyrocketed recently. Rice prices have increased 50 percent in the past year, while wheat prices went up 115 percent in the same time period. The high prices have been attributed to increased fuel and shipping costs, plus a worldwide grain shortage.

In response to the shortage, India has placed limited restrictions on rice exports to protect its domestic food supply, while Argentina, China and the Ukraine have all restricted exports of wheat and other grains. In an unprecedented move, the President of the Philippines recently made a personal appeal to Vietnamese Prime Minister Nguyen Tan Dung, asking Nguyen to guarantee the Philippines a set quantity of rice imports.

The Philippines is heavily dependent upon rice imports to feed its population.

“This is a wake-up call,” said Robert Zeigler of the International Rice Research Institute. “We have a crisis brewing in rice supply.”

Rice is a primary food source for half of the world’s population.

The global grain shortage has been blamed on droughts and other unusual weather caused by global warming, as well as the increasing diversion of grain into animal feed to meet the growing demand for meat and dairy products, especially in Asian countries.

The prices of foods made with grains, such as bread and beer, are also on the rise. In addition, the increased costs of animal feed are being felt in higher prices for meat, dairy and eggs.