Food prices are up as corn prices have doubled to $4.50/bushel with the $0.51/gallon of ethanol subsidy. As the US is (soon to be was) a huge corn exporter, this is causing higher prices worldwide. Foreign Affairs in the May/June issue says that could lead to doubling the world hungry from 600 million to 1.2 billion. They hope that

relying more on sugar cane to produce ethanol in tropical countries would be more efficient than using corn and would not involve using a staple crop.

No, if sugar cane is more profitable than corn, it will also outcompete staples for land and labor until the price of staples is hungry high.

Scientific American makes the same mistake in the June issue:

[Jatropha, an oil crop] favors hot, dry conditions and hence an unlikely threat to rain forests. There is no trade-off between food and fuel either, because the oil is poisonous.

No, Jatropha will pull away farm equipment, labor and land from other crops driving up the price of every other crop.

Ethanol is an OK energy delivery system to convert solar energy, but if biofuels stay competitive with petroleum (via subsidies for now), all arable land will be converted to corn and other energy crops until the food crop prices are driven up enough to be competitive with the energy crops.

The only way to bring the corn price down is to either bring a multiple of the current acreage under cultivation (all US arable land devoted to corn would get us 12% of petroleum consumption) or reducing the corn/ethanol subsidy.