Of course crops used for bio fuel adversely affect the availability of food globally. There are only so many crops in any given country and when some of these are used for fuel, rather than feed, then the food supply is decreased. Anyone who thinks this is not the case is terribly misinformed.
There is a finite amount of arable land. So when crops are planted for fuel for vehicle instead of fuel for people then the food supply will be adversely affected. As the price of fuel continues to rise when can expect the more land to be devoted to biofuels. But as more land is devoted to biofuels this will cause the price of food to rise making the planting of fuel crops more appealing. The situation is likely to reslove itself in some optimum way.
Yes, the crops used for biofuel have an adverse affect on the availability of food globally. Biofuel uses a large share of our farmers corn crops. Before biofuel, this corn was destined to be either cattle feed used domestically, or exported to other countries. The emergence of biofuel created an additional market for the corn, without the ability to increase corn production. This has caused corn prices to rise dramatically and greatly reduced exports.
I think the production of biofuel has been done at a steady, moderate pace. And because of this and the fact that there isn't technologies using this fuel worldwide yet, it won't have an impact on the availability of food. By the time it's needed, we will already have it stockpiled.