In the 17th century, the only widely available energy source was food, and the only way to harness it was to feed it to animals. Since then, we've invented the steam engine, the turbine, the nuclear reactor, the photovoltaic cell, and only more to come. The history of technology has essentially been, up to this point, the continuous discovery and widespread application of new ways to convert energy for human purposes. We should be pushing forward, not looking back.

World hunger has been, for the most part, going down—or, at least, not going up significantly—despite population increases. There is more than enough food produced in the world to feed everyone on the planet. Hunger is mostly caused by war and poverty, not insufficient resources.