A Cornell University research group had developed a new biological substitute for a petroleum product by making plastic from oranges.

The process uses limonene oxide and carbon dioxide and a newly discovered "helper molecule." Limonene is a carbon-based compound that is found in more than 300 plant species, but in oranges it makes up about 95 percent of the oil in the peel.

This is another indication that our modern society can continue on without oil--but only within certain limits. Bio-solutions are limited by the available farmland, and farmland is under pressure from expanding urban areas, dwindling water supplies, and overuse.

In "The Graduate" Dustin Hoffman was given just one word of advice by an overbearing neighbor--"plastics." It was very prescient advice for the time. For the Twenty-First century, the one world that everyone should know is "sustainability."