Common sense would suggest that the world population hasn't massively increased in the last couple weeks, and so in all likelihood the food cost increases and shortages (many grains have increased in price over 100% on the world market over the last year and China and India have announced they will stop exporting rice in order to make sure they have enough to feed those in their own countries) are at least somewhat related to a decrease int he supply of food resulting from diverting grain to fuel production.
However, I try to keep a wary eye on explanations that are too ideologically convenient, so I'd assumed that the impact of bio-fuel couldn't be all that increadibly huge, and that a fair amount of the increase in grain cost must be mainly the result of increased oil costs driving up the costs of running farm equipment and transportin grain to market destinations. Perhaps I was too cautious in this, however. Deroy Murdock writes in a piece last week:
As ReasonOnline’s Ronald Bailey observed April 8, “the result of these mandates is that about 100 million tons of grain will be transformed this year into fuel, drawing down global grain stocks to their lowest levels in decades. Keep in mind that 100 million tons of grain is enough to feed nearly 450 million people for a year” — assuming 1.2 pounds of grain each, daily.His source on the tonage of grain slated to be turned into bio-fuels this year is this Reuters piece. Not only are we burning all that grain at a time when grain is in short supply in poverty-stricken parts of the world, but since producing ethanol as fuel is currently less efficient than using petroleum, one can't even argue that all this is necessary to keep transportation costs from skyrocketing further and increasing food costs.
In short, car engines are burning the crops that feed a half-billion people. That has to hurt.
Not to say that bio-fuels will never under any circumstances be a good idea. It's quite possible they will be someday. But I don't see how the mandated burning of enough food to feed half a billion people is a good idea at a time when there are bread riots in the third world.