Sweet fuel

Mention alternative fuels to most people, and they are likely to think of ethanol-spiked biodiesel and perhaps cooking oil—unless they're Andy Pag and John Grimshaw. The British environmentalists drove a truck fueled by chocolate some 4,500 miles (3,600 kilometers) across Europe and Africa. Their purpose, they told reporters, was to raise awareness of "green" fuels and the dangers of climate change. "I wanted to do something that's carbon-neutral," Pag told the BBC. "What we [are doing] is actually carbon-negative."

Recent news reports about farmers destroying areas of rainforest to grow crops for biofuels led the pair to try an often-wasted resource: cocoa butter. To power the truck, they used cocoa butter extracted from nearly 9,000 pounds (4,082 kilos) of rejected chocolate "misshapes"—the equivalent of 80,000 chocolate bars. According to Ecotec, the sponsor of the road trip, some two million liters (about 528,000 gallons) of fuel could be created from the waste generated by a single chocolate factory.

The pair salvaged an aging Ford truck from a scrapyard to demonstrate the value of recycling old equipment. They traveled for about one month, starting in Great Britain and passing through such countries as Spain, Morocco, and Mauritania before reaching their final destination, Timbuktu in Mali. Now the pair reportedly has plans for another carbon-neutral adventure: flying to China on a motorized paraglider fueled by landfill waste.