Once again, the World Food Program is warning that unless donors step up it will have to start rationing food aid.

The Rome-based World Food Program said it issued the appeal in a letter sent to governments on Thursday, urging them to be as generous as possible by May 1 so the WFP will not have to begin rationing food aid.

The agency estimates that in Darfur alone it needs to provide emergency food for as many as 3 million people daily. The organization, the world's largest humanitarian agency, gives food to as many as 70 million people worldwide.

Earlier this month, WFP executive director Josette Sheeran said that the high prices of food and oil have been swelling the ranks of the hungry since last summer, and cautioned that the crisis would continue for several years.

Sheeran said that a 40 percent rise in the cost of fuel and commodities such as grain since mid-2007 have raised the cost of food and transport, causing the shortfall in the agency's 2008 budget.

The WFP says it needs $125 million to cover transportation costs and $375 million to purchase new food stocks. But this is just the humanitarian face of a larger global crisis. As Ban wrote a couple weeks ago rising food prices are also fomenting political instability around the world.

Food riots have erupted from West Africa to South Asia. In countries where food has to be imported to feed hungry populations, communities are rising to protest the high cost of living. Fragile democracies are feeling the pressure of food insecurity. Many governments have issued export bans and price controls on food, distorting markets and presenting challenges to commerce.

In January, to cite one example, Afghan President Hamid Karzai appealed for $77 million to help provide food for more than 2.5 million people pushed over the edge by rising prices. He drew attention to an alarming fact: The average Afghan household now spends about 45 percent of its income on food, up from 11 percent in 2006.

Other than Free Rice enthusiasts, it seems that few people in donor countries paying much attention to this emerging global crisis.