You might want to revisit this April 1, 2007 post: The Green Revolution's Outer Limits.

The BBC story looked at whether the world can produce enough food to feed the estimated nine billion expected to inhabit it by mid-century -- in other words, is a second act to the Green Revolution of the 1960s possible? Barring an unforeseen scientific breakthrough, it would appear unlikely.

There are other parts to the series:

March 28, 2007: Tiny island with a global warning

March 31, 2007: Obesity fueled by cheaper food

This page archives the podcasts of the Feeding the World series.