Santa Monica, California, USA
Tom Mark -- You burn the car for fuel and eat the driver!
John, I suspecting that you are setting up a hypothetical but plausible situation. Yes, when the price of producing corn doubles and the price of tortillas, for example, doubles as a consequence, their are and will be more worldwide riots over foodstuffs. But the problem is not yet the diversion of corn, beans, yams, potatoes, cassava, of whatever to a fuel making process. I don't think it is going to go there, but what do I know?
On the other hand, there are some real here and now sustenance crop issues.
Since the question is hypothetical I'll offer up an example which is true in fact but not in the details. That is, it happened, but not exactly this way.
In 1982, the US Department of Agriculture in assistance to to the country of Tchad, gave a large grant to the AG School at Colorado State University to develop a strain of beans, the Tchad subsistence crop, which was more productive during drought conditions.
After five years of work, the Ag researchers at CSU came up with a strain of the Tchadian bean which was twice as productive as the original bean in stressed conditions.
Was this of any benefit? No. The original Tchad bean was deep mahogany colored with black spots. The CSU hybrid was light brown with darker brown spots.
The peoples in Tchad preferred to kill each other in order to acquire more land to grow less productive beans of the preferred color. And so they did and do.
Similarly, certain religious sects in India refuse to kill the rats which consume about 30 per cent of their stored grain. They prefer to watch people starve to death.
Food cropland converted to fuel cropland is still pretty low on the list of starvation related insanities.